By Eben van Tonder and Christa van Tonder-Berger, 7 August 2026

Abstract

This document establishes the scientific and practical framework for using skin and connective tissue as functional ingredients in comminuted and restructured (pressed) meat systems. This spans emulsified sausage, coarse fresh sausage, hamburger patties, formed and pressed ham, sandwich ham, reformed bacon, and whole muscle bacon and ham where these systems apply. It distinguishes three related processes built on the same anatomical raw materials. Hautstoß is the heat cut, hydrolysed skin product. Sehnenstoß is the heat cut, hydrolysed connective tissue product, taken from tendon, sinew, epimysium and the silverskin trimmed from around whole muscles. Salzstoß is a separate, cold process. It uses raw, unprocessed connective tissue trim, most often the silverskin and sinew removed during the preparation of ham, bacon and other whole muscle primals, comminuted through a fine plate and salted to build structural rigidity, not gelatin. Klebemasse remains the clean meat glue system against which Salzstoß is now compared. The document is grounded in three interlocking bodies of research: the Bundesanstalt fur Fleischforschung (BAFF) Kulmbach tradition (Kotter and Pralat, 1981); the Nebraska body of work by Osburn and Mandigo (1996, 1997, 1998, 1999); and the South African applied research of Mapanda, Hoffman, Mellett and Muller (2011, 2015). The Mexican research of Güemes-Vera, Yanez-Fernandez, and Totosaus on pork skin collagen in frankfurters is incorporated for regional context. Section 4 sets out recent bench observations on Salzstoß, published as Van Tonder (2026), which suggest that Salzstoß may match or exceed the glue function of Klebemasse. These observations are stated as observations. They are kept separate from the established literature that explains the mechanisms behind them, and they await instrumental confirmation. Section 7 provides complete standalone preparation recipes for four Hautstoß and Sehnenstoß types. Water addition figures throughout this document refer to water added over and above what was used to make the Hautstoß or Sehnenstoß itself, treating the emulsion as a pre-made batch ingredient. All temperatures are in degrees Celsius.

1. Introduction and Scope

This document reviews work done over the past two years in Austria, Germany and Lagos, Nigeria. Christa van Tonder-Berger grew up on a farm in Styria and trained under the Austrian master butcher tradition through her mother’s work with Marcel Kropf. That training shaped the Klebemasse and Salzstoß groundwork, the cold, meat only approach to binding and rigidity that this document builds on.

The heat cut system itself, Hautstoß and Sehnenstoß, began in West Africa as a direct progression of the Salzstoß work on Zebu cattle. Salzstoß in Lagos started as raw, cold, salted connective tissue trim, following the method set out in Section 4. Applying heat to that same material, an extension of the Salzstoß work rather than a separate line of enquiry, showed that collagen hydrolysed to gelatin under heat was exactly what a comminuted meat system needs for water binding. That observation, made in West Africa on Zebu raw material, is the origin of the heat cut system documented in Section 3. Zebu skin and connective tissue have a different crosslink profile from the young bulls and pigs used in the original Kulmbach studies, because Zebu animals are older and worked harder over their lifetime. The European literature cited throughout this document, the Kulmbach tradition and the Nebraska body of work, supplied the scientific framework for understanding why the West African observation held. It did not supply the observation itself.

Work on Salzstoß continued in West Africa alongside this. Passing raw connective tissue trim through a plate four times, first a kidney plate, then 4.5 mm, then twice through 3 mm, reduced particle size enough to make the trim workable without pre-boiling it. This route depended on freezing the raw material before comminution rather than boiling it. Boiling was not abandoned. Both routes, the frozen multi-pass grind for Salzstoß and boiling for Hautstoß and Sehnenstoß, stayed in use side by side, since they serve different products.

Earlier work at Green Cell Technologies in Cape Town, using their Dynamic Cellular Disruption process, showed what a properly formed, solid gel structure of boiled collagen looks like, and what state the collagen needs to reach before cutting. That reference point made it possible to reproduce a comparable texture using only a bowl cutter, without the specialised Green Cell equipment. The bowl cut version held the bulk of the water an emulsified sausage, a mortadella or bologna style ham, a formed or pressed ham, or a reformed bacon needs, across beef, pork and chicken, with results better than expected going into the work. One further, unexpected result came out of the poultry work. Removing the silverskin sheath from around a chicken fillet and processing it the same way also worked well in whole muscle chicken ham production.

This document is not a separate regional adaptation, and it is not written only for an African production environment. It is a technical reference for any comminuted or restructured meat system that uses skin and connective tissue as functional ingredients, whether the finished product is a fine emulsion, a coarse fresh sausage, a hamburger patty, a formed or pressed ham, a sandwich ham, a reformed bacon, or a whole muscle bacon or ham built around a Salzstoß, Klebemasse, Hautstoß or Sehnenstoß component. It is built from a West African discovery and explained through European and American literature. Where Lagos conditions required a change to method, this document states the change and gives the reason. Where the same principle held without change, this document states that as well.

Hautstoß names the heat cut, hydrolysed skin product. Sehnenstoß names the heat cut, hydrolysed connective tissue product. Salzstoß names the cold, unhydrolysed trim generated as a by-product of ham and bacon primal preparation, silverskin and sinew trimmed from around whole muscles, distinct from both of the heat cut systems. This document is informed by current European and Nigerian bench practice and by the modern water binding literature, rather than by older treatments that reduce collagen and connective tissue to an inert filler.

Across every system documented here, the process contributes as much as the ingredient, and often more. Particle size, grinding sequence, temperature, the physical state of the collagen, the physical state of the meat, timing, and mixing intensity repeatedly decide whether a given raw material binds, gels, or fails, independent of what that raw material is. Two batches of the same silverskin trim, ground to the same final particle size but by a different route, do not behave the same way. Processing history is as important as ingredient composition, and this document treats it that way throughout, rather than describing outcomes as though ingredients alone produced them.

This has a consequence for how the whole system should be read. Conventional formulation practice asks what ingredient solves a problem: soy for water binding, starch for yield, carrageenan for slice. This document asks what function is needed, adhesion, rigidity, water holding, collagen functionality, or fat stability, and then supplies the module built for that function. Klebemasse manages adhesion. Salzstoß manages rigidity. Hautstoß manages water. Sehnenstoß manages collagen functionality. Fettstoß, introduced in Section 2.5, manages fat. Read this way, the document is not a description of five separate products. It is a functional formulation system, where each module can be chosen, combined, or left out according to what the product needs, in the same way an engineer selects a component for its function rather than its familiarity.

The practical recommendations in this document arise from production work. Where a recommendation is supported directly by published literature, it is presented as established practice. Where a recommendation arises from recent production observation, it is identified once, plainly, as an observation awaiting quantitative confirmation, and that status is not repeated at every subsequent mention.

2. Terminology: Klebemasse, Hautstoß, Sehnenstoß, Salzstoß and Fettstoß

Five related but distinct terms are used throughout this document. They share raw materials in some cases, and they are frequently confused with one another because most of them involve skin, sinew, tendon or the meat trimmed alongside them. The heat cut sausage system described in Section 3 is not Salzstoß, even though the two are easily confused, and the distinction is set out below and used throughout the rest of the document.

2.1 Klebemasse: Clean Meat, Cold Process, Glue Function

Klebemasse is made from clean primal meat trim, free of skin, sinew and silverskin. It is fine minced, typically through a 3 mm plate, and paddle mixed with salt. No heat step is involved. Salt extracts myofibrillar protein, mainly myosin and actomyosin, from the meat surface created by comminution. This extracted protein forms the sticky surface layer that binds pieces of meat together on cooking. Klebemasse is built to provide glue, the extra adhesion that holds pieces of meat together in a formed or reformed product and prevents them from separating on slicing. It is not built to provide rigidity on its own.

2.2 Hautstoß: Heat Cut Skin

Hautstoß is the name used in this document for skin that has been boiled or cooked under pressure, hot comminuted while the gelatin phase is still fluid, and finished as an emulsion. Hautstoß can be made from beef skin, pork rind or chicken skin. Whichever species it comes from, the process and the function are the same. Collagen is hydrolysed to gelatin through extended heat, and the gelatin is dispersed into the product while still hot, following the Kulmbach principle documented by Kotter and Pralat [1].

Hautstoß is not simply gelatin, and describing it that way understates what it is. Hautstoß is a gelatin rich, dispersed collagen phase. Alongside gelatin it includes residual, incompletely hydrolysed collagen fragments, other dissolved proteins released during cooking, retained fat, minerals from the raw material and the cooking liquor itself, all held together as one phase once bowl cut. Each of these fractions contributes something to the finished emulsion, not gelatin alone, and this is part of why Hautstoß performs differently from a purified commercial gelatin at the same inclusion level. Once cooled, the gelatin fraction sets into a thermoreversible gel that binds water and contributes bulk and juiciness. Hautstoß does not contribute snap or elastic bite. Section 3 sets out the Hautstoß gelatin system in full, and Section 7 gives standalone recipes for beef, pork and chicken Hautstoß.

2.3 Sehnenstoß: Heat Cut Connective Tissue

Sehnenstoß is the name used in this document for tendon, sinew and other collagen dense connective tissue that has gone through the same hot process as Hautstoß. Tendon comes away from the carcase largely free of adhering muscle tissue, so a Sehnenstoß raw material is close to pure Type I collagen with very little sarcoplasmic or myofibrillar protein attached. This makes Sehnenstoß a useful way to isolate the collagen contribution from the meat protein contribution, because the two mechanisms behind bind, myofibrillar extraction on one hand and collagen hydrolysis to gelatin on the other, can be studied and used separately when the raw material is nearly pure collagen.

Sehnenstoß, like Hautstoß, is cooked at 85 to 98°C for an extended period, with water added during cooking. Extended cooking at this temperature hydrolyses the collagen through to gelatin, and the purpose of that gelatin is water binding, holding water in the finished product. It is not built to create a Klebemasse type rigid protein matrix. Sehnenstoß and Hautstoß share raw materials with Salzstoß in a broad sense, both begin as connective tissue or skin, but they do not share a mechanism, and neither should be substituted for the other. Section 6 gives the Nebraska data underlying Sehnenstoß performance, and Section 7.3 gives the standalone recipe.

2.4 Salzstoß: A Processing Technology, Not Just an Ingredient

Salzstoß is a different category from Hautstoß and Sehnenstoß, and it is the term most often confused with them. Describing Salzstoß only as an ingredient, raw silverskin and sinew trim, misses what actually does the work. The raw material is simply silverskin. Salzstoß is the technology applied to it: trim it correctly, grind it repeatedly to the right particle size, salt it, extract protein from the meat riding along with it, hydrate it, rest it, and incorporate it. Any one of these steps done differently changes the outcome, which is why Salzstoß is treated in this document as a process to be controlled, not a raw material to be sourced and used as is.

The raw material itself is the silverskin and epimysium removed from around whole muscles during ham, bacon and reformed product preparation, along with sinew and fascia trimmed during general carcase breakdown. No boiling or hydrolysis step is involved. Salzstoß trim is comminuted cold, typically through the same 3 mm plate used for Klebemasse, and paddle mixed with salt.

Because silverskin and epimysium lie directly against the muscle fibre, they cannot be lifted away from a primal without taking a layer of adhering muscle tissue with them. Salzstoß trim therefore always includes some meat alongside the collagen. This is the reason salt is still added to Salzstoß even though salt does very little to the tendon and collagen fraction itself at cold, unhydrolysed temperatures. Salt’s established role in comminuted meat is extraction of the salt soluble myofibrillar proteins from the meat fraction, not disruption of collagen crosslinks, and pyridinoline crosslinks in mature collagen are heat stable and unaffected by salt at these temperatures [2, 3]. Salt therefore has a job to do in Salzstoß trim because meat is always present in it, not because it does anything to the collagen.

The demonstrated production function of Salzstoß is rigidity, the firmness that holds a formed or reformed product together as one solid piece. This is different from the glue function of Klebemasse. Recent bench observations, reproduced in full in Section 4 and published separately as Van Tonder (2026) [21], suggest that Salzstoß may also perform the glue function at least as well as Klebemasse, and possibly better, because the fine plate tears the collagen sheets in the trim into small aggregates with far more surface area than an intact sheet. This is stated here as an observation awaiting formal testing, not as an established finding, and Section 4 treats it accordingly.

2.5 Fettstoß: Fat Management

Fettstoß completes the functional system rather than standing apart from it as a separate discovery. Where Klebemasse manages adhesion, Salzstoß manages rigidity, Hautstoß manages water, and Sehnenstoß manages collagen functionality, Fettstoß manages fat, dispersing it into a matrix in a controlled, stable form rather than leaving it to render, pool, or separate unpredictably during processing. Fettstoß formulation and inclusion levels are under active development and are not yet documented with the same completeness as the other four systems in this reference. It is introduced here so that the five part framework is stated in full, and it will be built out with recipes and formulations, including its correct accounting against lean meat inclusion, in a future revision.

2.6 Practical Applications for Sehnenstoß Beyond Sausage

Sehnenstoß is documented throughout this reference primarily in sausage and reformed products, but its function, holding water inside a collagen rich gelatin phase, applies wherever moisture retention during processing or storage matters. This includes pet food, high protein convenience meals, canned meat, pie fillings, dumpling fillings, meatballs, kebabs, kofta, meat loaf, pulled meat products, and ready meals generally. In each of these categories, the same mechanism documented in Sections 3 and 4 applies: collagen hydrolysed to gelatin binds water inside the product through cooking, chilling, freezing, reheating, or shelf storage, in exactly the way it binds water inside a sausage batter. The specific inclusion levels and recipes for these categories are outside the scope of the current formulations in Section 11, and should be established by the same trial process used for the sausage and ham formulations documented there.

2.7 Choosing the Right System

Need	Use
More adhesion	Klebemasse
More rigidity	Salzstoß
Higher yield through water binding	Hautstoß
Higher collagen functionality, isolated from meat protein	Sehnenstoß
Stable fat management	Fettstoß

Table B. A processor choosing a functional module starts from the need, not from a familiar ingredient. Klebemasse, Salzstoß, Hautstoß and Sehnenstoß are documented in full in this reference. Fettstoß is introduced conceptually in Section 2.5 and will be documented in full in a future revision.

2.8 Summary Table

Term	Process	Typical raw material	Mechanism	Function
Klebemasse	Cold, no heat step	Clean primal meat trim, no skin or silverskin	Salt extraction of myofibrillar protein from meat	Glue, adhesion between meat pieces
Hautstoß	Hot, 85 to 98°C, extended cooking	Beef skin, pork rind, chicken skin	Collagen hydrolysed to gelatin	Water binding, bulk, juiciness, no snap
Sehnenstoß	Hot, 85 to 98°C, extended cooking	Tendon, sinew, connective tissue with little adhering meat	Collagen hydrolysed to gelatin	Water binding, isolates the collagen only contribution
Salzstoß	Cold, no heat step	Silverskin and sinew trimmed from primals, always includes some adhering meat	Salt extraction of myofibrillar protein from the adhering meat fraction	Rigidity, demonstrated production function, and possibly glue, per Section 4
Fettstoß	Under development	Animal fat	Controlled dispersion of fat into the matrix	Fat management, stable fat phase

Table C. The five systems compared. For Klebemasse, Hautstoß and Sehnenstoß, the function listed follows directly from mechanisms established in the cited literature. For Salzstoß, the literature establishes the mechanical role of connective tissue and the effects of comminution and extracted myofibrillar protein; Salzstoß as a defined process, and rigidity as its named function, is this document’s own demonstrated production system built on that mechanism, not a function the cited literature names as such.

3. The Two Systems: Same Kulmbach Principle, Different Structure

Both the Hautstoß patty system and the HeatCut Hautstoß / Sehnenstoß sausage system share the same foundational principle documented by Kotter and Pralat at BAFF Kulmbach [1]: connective tissue and skin must be hot-comminuted immediately after cooking so that the gelatin phase remains fluid at the moment of dispersion into the batter. Once the gelatin sets, cold mechanical mixing cannot recreate the continuous phase. Complete remelting above the gel’s melt temperature can, and Section 8.3 gives the correct route when same-day hot incorporation is not possible.

The systems diverge in what the gelatin does inside the final product. This divergence determines everything about formulation, water limits, comminution sequence, and the achievability of snap.

3.1 The Hautstoß Gelatin System

Gelatin is the structure. In a burger patty with 40 to 55% beef skin, myofibrillar protein is insufficient to form a dominant myosin gel matrix. Structure is provided primarily by the thermoreversible gelatin network from boiled skin collagen, supported by hydrocolloids and starch.

• Cold-state cohesion: strong. Below the gel set temperature (25 to 32°C) the gelatin is a firm solid.
• Thermal vulnerability window: between approximately 47 and 65°C, the gelatin phase is liquid. Methylcellulose, at 0.3 to 0.5%, can bridge this window in a gelatin-dominant product where gelatin holds most of the structure. Section 10.3 discusses this cost and when it is worth paying. Section 11.1 shows the alternative used in this document: build the product myofibrillar-protein-dominant instead, so the gap does not need bridging in the first place.
• No snap. No elastic bite. Gelatin provides bulk, juiciness, water binding, and non-stick frying surface.
• Juiciness is retained gelatin-phase water released on chewing.

3.2 The HeatCut Hautstoß / Sehnenstoß System

Gelatin supports a myofibrillar protein matrix. In a sausage with 15 to 20% beef skin or connective tissue alongside 30 to 45% lean meat and 20 to 30% MDM, myofibrillar proteins extracted by salt and phosphate form the dominant structural matrix. Snap, elastic bite, sliceability, and structural integrity through the full thermal cycle come from the myosin gel, not from gelatin.

The snap of the SA Russian or Hungarian sausage comes entirely from the myofibrillar protein system and casing tension. Gelatin contributes nothing to snap and can only dilute it by reducing the lean meat fraction below the critical minimum.

3.3 Comparative Summary

Property	Hautstoß Gelatin System	HeatCut Hautstoß / Sehnenstoß System
Primary binding agent	Thermoreversible gelatin (skin collagen)	Myosin heat-set gel (lean meat)
Role of gelatin	Gelatin IS the structure	Gelatin SUPPORTS the protein matrix
Role of myofibrillar protein	Anchoring only; minority phase	Dominant structural phase
Thermal stability 47-65°C	Weak: gelatin melts above 47-52°C	Stable: myosin sets above 50-60°C
Post-cooking snap	None	Good: myosin gel provides elastic bite
Juiciness mechanism	Retained gelatin-phase water	Combined myosin WHC and gelatin
Skin / CT inclusion level	Up to 55% in patty	Max 20% in sausage
Lean meat minimum	10-15% for structural anchoring	25-35% for snap and structure
Optimal product type	Burger patty, reformed bacon	SA Russian, Hungarian, frankfurter

Table 1. Structural comparison of the two systems. References: [1, 6, 7, 8]

4. Salzstoß: The Cold Process and the Glue Question

This section reproduces and expands bench observations recorded after one month of using Klebemasse, Salzstoß, Hautstoß and Sehnenstoß together as the basic building blocks of sausage, ham and reformed bacon production, without starch, isolate or textured vegetable protein. The observations were first published as Van Tonder (2026) [21]. Where the literature supports or explains an observation, that literature is cited. Where the observation goes beyond what has been published, this section says so plainly, because the distinction changes how the finding should be used in production.

4.1 Salzstoß Trim Always Includes Meat

When silverskin or epimysium is trimmed off a primal, the trim is never collagen alone. Silverskin and epimysium lie directly against the muscle fibre bundles they surround, so a portion of muscle tissue always comes away with the collagen. This is a physical consequence of trimming, not a preparation choice, and it applies whether the trim comes from a ham primal, a bacon primal or general carcase breakdown.

Because Salzstoß trim always includes a meat fraction, salt added to Salzstoß is not working on collagen alone. It is working on the meat fraction riding along with the collagen, in the same way it would work on a clean primal cut. Salt’s primary functional role in comminuted meat is extraction of the salt soluble myofibrillar proteins, mainly myosin and actomyosin, and the literature on protein extraction places the optimum pH for this around 6.5 to 7.0, with an ionic strength above roughly 0.3 M needed before extraction proceeds [23]. This mechanism is identical whether the meat fraction is a clean primal cut or the thin layer of muscle tissue riding along on a piece of trimmed silverskin. This is why salt still makes sense in trim that is mostly collagen. It has meat to work on, even though it does very little to the tendon and collagen fraction itself.

4.2 Salzstoß Builds Rigidity, Klebemasse Builds Glue

Klebemasse and Salzstoß are built for different jobs. Klebemasse is not built to give a product rigidity. Its job is glue, the extra adhesion that holds pieces of meat together and prevents them separating on slicing. Salzstoß has a different primary job. It builds rigidity into the mix, the firmness that holds a formed or reformed product together as one solid piece. The bench observation behind this section is that Salzstoß may do more than its primary job, and may match or exceed Klebemasse’s glue function as well.

4.3 Sehnenstoß as a Contrast: Isolating the Collagen Only Fraction

Sehnenstoß, tendon put through the same fine mince as Salzstoß, behaves differently from Salzstoß because tendon comes away from the carcase largely free of adhering muscle tissue. Beef sinew is close to pure Type I collagen with very little sarcoplasmic or myofibrillar protein attached. Sehnenstoß is therefore a useful differentiator in the wider product system. It isolates the connective tissue contribution from the meat protein contribution, so that the two mechanisms behind bind, myofibrillar extraction on one hand and collagen disruption followed by thermal gelatinisation on the other, can be studied and used separately. Salzstoß, by contrast, always involves both mechanisms at once, because it always includes some meat. Section 2.3 sets out how Sehnenstoß and Hautstoß differ from Salzstoß in mechanism as well as in process.

4.4 What the 3 mm Plate Does to Collagen

The mechanical action of mincing through a 3 mm plate is not simply size reduction. It is a directional tearing action. The knife and plate combination shears the collagen sheath, mainly perimysium and epimysium, away from the muscle fibre bundles it surrounds, rather than cutting cleanly through it. Epimysium is composed almost entirely of Type I collagen, and bovine epimysial tissue has been measured at around 24 percent collagen on a wet weight basis, with gristle running to about 27 percent, arranged as sheets rather than dispersed fibres [22]. When these sheets are torn rather than sliced, the result is small collagen aggregates, effectively balls of torn sheath, rather than the large continuous sheets present in the intact muscle.

Intact silverskin sheets present a large, continuous, low surface area barrier inside a product. They do not take up salt evenly, they do not hydrate evenly, and in a finished product they behave as a mechanically distinct phase, a plane of weakness rather than something built into the matrix. Once the same collagen is torn into small aggregates by the fine plate, its surface area rises sharply. This mirrors the established finding for meat particle size generally, where comminution raises surface area and, as a direct consequence, increases the amount of myofibrillar protein available for binding [24, 27]. Small collagen aggregates can be salted, hydrated and coated in extracted myofibrillar protein far more evenly than a sheet ever could. On cooking, this same collagen converts partially to gelatin, and a well dispersed gelatin phase contributes adhesive strength to the matrix instead of remaining inside it as an inert sheet.

4.5 Why Torn Collagen May Bind Better Than Meat Protein Alone

The established mechanism for binding in any comminuted meat product runs as follows. Salt at sufficient ionic strength solubilises myosin and actomyosin at the cut surface of the meat particle. This extracted protein forms a sticky, viscous surface layer, and where fat is present it forms an interfacial protein film around the fat droplet, which sets on cooking into a continuous gel network that holds particles, fat and water together [23]. Because extraction happens at the cut surface, the amount of surface area created by comminution is directly proportional to how much salt soluble protein can be recruited into that film in a given mixing time. This is why particle size and plate hole size are treated as primary process variables in the literature, not secondary ones. Reducing plate hole size and comminuting more finely repeatedly raises water binding capacity and reduces cook loss [26, 27]. A fine plate in the 2 to 3 mm range is treated as the range for a smooth bind in classic emulsified products, while a medium plate in the 4 to 6 mm range is reserved for everyday burgers and meatballs, and a coarse plate for rustic, chunky fillings.

A 3 mm Salzstoß mix has more cut surface per unit weight than a 4 mm clean meat mix, so more myofibrillar protein is available for extraction within the same paddle mixing time. Comparing a 3 mm Salzstoß mix to a 4 mm clean meat Klebemasse mix therefore changes two variables at once, plate size and the collagen content of the raw material, so the collagen story cannot claim credit for all of the difference on its own. The current Klebemasse protocol used for comparison in Van Tonder (2026) [21] holds plate size and mixing time constant against Salzstoß, which isolates the raw material as the remaining variable.

Two things happen together in a Salzstoß mix that do not happen, or happen to a much lesser extent, in clean meat Klebemasse. First, myofibrillar protein extraction proceeds from the meat fraction exactly as it would in clean meat. Second, the torn collagen aggregates, once hydrated and partially gelatinised on cooking, are mechanically present inside the matrix in a form clean meat, being nearly free of collagen, does not have available to it in the same concentration. The observations reported here are consistent with torn collagen aggregates contributing mechanically to the finished bind, although the relative contribution of the collagen fraction and the extracted myofibrillar proteins has not been quantified, and the exact mechanism by which the collagen fraction contributes, whether through adhesion, through the composite reinforcement effect set out in Section 4.6, or through some combination of the two, has not been established experimentally. Whole muscle collagen studies show that collagen content and fibre diameter correlate strongly with the mechanical properties of the tissue in which they are measured, with both collagen fibre diameter and collagen content in the perimysium and endomysium tracking meat toughness closely [22]. That literature describes toughness in intact meat rather than bind in a comminuted matrix, but it confirms that collagen is mechanically active and concentration dependent, consistent with a well disrupted collagen fraction contributing measurably to the strength of a cooked matrix rather than merely being tolerated in it. The restructuring literature establishes that disrupted collagen, mainly from perimysium and endomysium, is not simply tolerated in comminuted products and can make a positive contribution, because comminution destroys its structural continuity and prevents it being detected as a texture defect once it is broken up enough [24, 25].

4.6 Composite Reinforcement: A Second, Distinct Mechanism

The account in Section 4.5 treats torn collagen as a possible contributor to adhesion, the same kind of contribution myofibrillar protein makes. There is a second, mechanically distinct possibility that this document has not previously addressed, and it deserves separate treatment because it is a different effect, not a restatement of the first.

Repeated grinding of silverskin through a fine plate does more than raise surface area for salt and protein extraction, the mechanism set out in Section 4.4. It also converts one continuous collagen sheet into a very large number of small, discrete collagen fragments, distributed through the surrounding myosin gel once the mix is cooked. This is structurally similar to short fibre reinforcement in composite materials, where a large number of small, well distributed reinforcing fragments embedded in a continuous matrix, the way steel or synthetic fibres are embedded in concrete, raise the fracture resistance of the finished composite without necessarily raising its adhesive strength at any single point.

If this mechanism is active in a Salzstoß mix, its effect is on fracture resistance, how much force the finished matrix can absorb before it splits or crumbles, rather than on adhesion, how strongly two surfaces stick together. These are different properties, measured differently, and a formulation could show an improvement in one without the other. This composite reinforcement effect has not been measured in this system, and this document does not claim it has been. It is presented here as a plausible second mechanism, grounded in general composite materials principles rather than in meat science literature specific to this application, and it offers one explanation for why Salzstoß trim performs as well as it does in practice. Confirming it would need mechanical testing designed to separate fracture resistance from adhesive strength, which is different from the gel strength or shear testing already proposed in Section 4.7 for the adhesion question.

4.7 An Unexpected Conclusion, Stated as an Observation

Trimming silverskin off ham cuts or reformed bacon primals is necessary regardless of what is later done with the trim, because intact sheets of silverskin inside a whole muscle product are a known defect. Put through a 3 mm plate and paddle mixed for twenty minutes, that trim has, in one month of bench work, matched or bettered the glue effect of the clean primal meat Klebemasse protocol used until then, while still doing the rigidity job Salzstoß is built for [21]. If this holds under proper testing, the trim stream from ham and bacon production is not simply a lower value by-product to be minced into economy sausage. It may do the work of two separate binding systems at once, and it may be, on current bench impression, a remarkable substitute for Klebemasse rather than a mere supplement to it.

The restructuring literature supports the individual mechanisms involved: the salt extraction mechanism, the surface area effect of comminution, the identity and distribution of collagen types in epimysium and perimysium, and the general tolerance of disrupted collagen in comminuted products are all supported by peer reviewed sources [22, 23, 24, 25, 26, 27]. The specific, measured comparison between the glue effect of Salzstoß and the glue effect of clean meat Klebemasse needs instrumental gel strength or shear testing, run with plate size, mixing time, temperature and salt level held constant across both raw materials. In formulation, Salzstoß should be treated as a proven rigidity agent with a promising glue function, per the introductory note on observation status in Section 1, not as a validated one to one replacement for Klebemasse.

5. Raw Material Behaviour

5.1 Beef Skin from Zebu Cattle

Beef skin is composed primarily of type I and type III collagen in the reticular dermis. In mature nomadic Zebu cattle (Bokolo, White Fulani, Sokoto Gudali), skin collagen has a high density of pyridinoline crosslinks: heat-stable mature crosslinks that accumulate with age and physical work [2, 3].

Gelatin conversion from 90 minutes of atmospheric boiling is estimated at approximately 60 to 75% of available collagen, based on production observation rather than analytical measurement on this specific raw material. Extending boiling to 120 minutes is estimated to raise conversion toward 75 to 85%, and pressure cooking at 121°C for 45 minutes is expected to achieve near-complete conversion even of heavily crosslinked Zebu collagen. Purslow [2, 3] supports the underlying crosslink biology, the reason older, harder worked Zebu cattle have denser, more heat stable crosslinks, but it does not report these specific conversion percentages for Zebu skin, and no analytical measurement of gelatin yield on this raw material has been done to confirm them. These figures should be read as working production estimates, not as established analytical results, until such measurement is done.

5.2 Connective Tissue: Sinew, Epimysium, Fascia

Connective tissue from carcass breakdown is less collagen-dense than skin but more heavily crosslinked per unit of collagen, particularly in shank and neck material from old Zebu cattle. Between 25 and 50°C during the sausage cook cycle, residual unhydrolysed connective tissue actually becomes stronger before the myofibrillar proteins have fully set [2]. This is why fine comminution before incorporation is essential. Particles above approximately 0.5 mm increase the risk of perceptible connective tissue in this temperature window in a fine emulsion sausage [12].

5.3 Comparative Raw Material Data

Property	Pig skin (Kulmbach [1])	Beef skin Zebu (estimated)	CT Zebu shank/neck (estimated)
Pyridinoline crosslink density	Low	High	Very high
Gelatin set temperature	23°C	25-30°C	30-35°C
Gelatin re-melt temperature	47°C	47-52°C	50-55°C
Required boiling time (atmospheric)	60 min	90-120 min	120-150 min
Gelatin conversion at minimum boil	Near complete	60-75%	50-70%
Optimal grind (hot)	4.5 mm → 3 mm	4.5 mm → 3 mm	4.5 mm → 3 mm → bowl cutter
Acceptable at 3 mm in sausage?	No	No	No: must reach <1 mm
Acceptable at 3 mm in patty?	Yes	Yes	Yes

Table 2. Raw material behaviour. Kulmbach data from Kotter and Pralat [1]. Zebu estimates based on crosslink biology [2, 3].

6. The Scientific Foundation: Kulmbach, Nebraska, South Africa, and Mexico

6.1 The Kulmbach Principle (Kotter and Pralat, 1981)

Kotter L, Pralat A (1981) The properties of connective tissue membrane and pig skin as raw materials for cooked sausage. Meat Science 5(6): 397 to 413. Bundesanstalt fur Fleischforschung (BAFF), Kulmbach. [1]

The foundational applied study from BAFF Kulmbach established the following findings, all of which underpin every emulsion recipe in Section 7:

• Pig skin and epimysial membrane from young bulls were comminuted in a colloid grinder, mixed with water and additives, heated in a water bath to 72°C, and centrifuged while still hot.
• As temperature rose, bound water content dropped but dissolved protein content and gel strength increased.
• The liquid released from connective tissue membranes gelled at 32°C and re-melted at 49°C. For pig skin, gel set was 23°C and re-melt was 47°C.
• Variations in salt content, phosphate content, added water amount, and pH within the ranges used in cooked sausage manufacture did not cause marked changes in water-bound content, dissolved protein, or gel strength once the gelatin was formed.

The last finding is critical: the gelatin phase, once formed by correct hot processing, is robust to formulation variables. This is why Mapanda could vary water additions substantially across his nine treatments without destabilising the rind emulsion phase.

6.2 The Nebraska Body of Work (Osburn and Mandigo, 1996 to 1999)

Osburn and Mandigo at the University of Nebraska conducted a systematic programme across three raw materials: desinewed beef shank connective tissue (BCT), chicken skin connective tissue (CCT), and pork skin connective tissue (PCT). The key references are:

• Osburn WN, Mandigo RW (1996) Gelatinized high added-water pork skin connective tissue protein gels as potential water binders. University of Nebraska Swine Day Report [4].
• Osburn WN, Mandigo RW (1996) Gelatinized high added-water beef connective tissue protein gels as potential water binders. University of Nebraska Animal Science Report [5].
• Osburn WN, Mandigo RW, Eskridge KM (1997) Pork skin connective tissue gel utilization in reduced-fat bologna. Journal of Food Science 62: 1176 to 1182 [4a].
• Osburn WN, Mandigo RW (1998) Reduced-fat bologna manufactured with poultry skin connective tissue gel. Poultry Science 77: 1574 to 1584 [5a].
• Osburn WN, Mandigo RW, Calkins CR (1999) Utilization of desinewed beef connective tissue gel in reduced-fat bologna. Journal of Muscle Foods 10: 29 to 50 [5b].

The 1998 Poultry Science paper is particularly important because it established, using chicken skin connective tissue (CCT), the practical inclusion framework for gels in finished products:

Raw material	Optimal heating (°C/time)	AW range tested	AW range used in finished product	Inclusion level in bologna
Pork skin (PCT)	70°C / 30 min	100-600%	100-300% AW PCT gels	10-30% of batch
Beef connective tissue (BCT)	70°C / 30 min	100-600%	100-400% AW BCT gels	10-30% of batch
Chicken skin (CCT)	60°C / 30 min	100-300%	100-300% AW CCT gels	10-30% of batch

Table 3. Nebraska optimal parameters for AW connective tissue gels and their inclusion in reduced-fat bologna. Sources: Osburn and Mandigo [4, 5, 4a, 5a, 5b].

Critical Nebraska finding: BCT gels at 100 to 600% AW, PCT gels at 100 to 600% AW, and CCT gels at 100 to 300% AW were incorporated at 10 to 30% of total finished product batch weight. In all cases, gel incorporation increased juiciness and acted as a practical water binder and texture modifier. The water already locked inside the gel entered the finished product as bound water, not as free water competing with the batter protein system. The total added water in the finished product therefore included both the emulsion water and any additional batter-stage water, and both were manageable at the levels used.

The practical optimum identified by Osburn and Mandigo for practical production is not the maximum 600% AW but a working range that balances gel stability, handling properties, and contribution to the finished product. For pork skin and beef CT, 200 to 300% AW is the recommended practical working range. For chicken skin CCT, 200% AW is the practical working limit because the high fat content of chicken skin destabilises gels above this level.

6.3 The South African Applied Framework: Mapanda, Hoffman, Mellett and Muller (2011, 2015)

The most directly applicable applied work for your Lagos production context is:

• Mapanda C (2011) Utilisation of pork rind and soya protein in the production of polony. MSc thesis, Stellenbosch University. Supervised by Hoffman LC and Mellett FD [17].
• Mapanda C, Hoffman LC, Mellett FD, Muller N (2015) Effect of pork rind and soy protein on polony sensory attributes. Journal of Food Process Technology 6(2): DOI 10.4172/2157-7110.1000417 [18].

The Mapanda study is the most important applied reference for your system because it demonstrates, in a South African regulatory and commercial context, exactly how a pre-made rind emulsion is prepared, incorporated, and supplemented with additional batter-stage water to reach a target product composition.

Step	Mapanda procedure	Key parameter
Rind emulsion preparation	7.5 kg raw rind cooked in 7.5 kg water for 4-5 hours	100% AW on raw rind weight in the emulsion itself
Emulsion finalisation	After cooking, water added back to make up 15 kg total. Bowl-cut to fine homogenous mass.	Total emulsion = 50% rind + 50% water by weight
Emulsion storage	Cooled to room temperature, vacuum packed, stored at -18°C until use	Note: this is the cold-store protocol; hot incorporation is preferred per Kulmbach [1]
Rind emulsion inclusion in polony	0%, 8%, or 16% of total polony batch weight	Pre-made emulsion weight, not raw rind weight
Additional batter-stage water	Adjusted per treatment to maintain constant product weight and 10% protein	Variable: water added over and above what was in the rind emulsion
Other batter additives (constant)	8% tapioca starch, 1.8% NaCl, 0.016% nitrite, 0.3% phosphate	Fixed across all nine treatments
Mixing sequence	MRM first, then salt/nitrite/phosphate + 1/3 water, then rind emulsion, then soy flour + 1/3 water, then starch + ascorbic acid + final 1/3 water	End temperature 12-17°C
Cooking	Steam bath, 2 hours, internal temperature 80°C	Note: 80°C internal is above the gelatin re-melt temperature of 47-49°C [1]

Table 4. Mapanda protocol for pork rind emulsion preparation and incorporation. Sources: Mapanda (2011) [17], Mapanda et al. (2015) [18], documented via EarthwormExpress.

Three conclusions follow from the Mapanda framework:

1. The rind emulsion water and the batter-stage water are separate, independent, and cumulative contributions to total product moisture. Mapanda varied the batter-stage water independently of the fixed emulsion water, adjusting it to reach his target protein percentage. He did not subtract emulsion water from a total water budget.
2. The rind emulsion is a pre-made ingredient with its own moisture content. When expressed as a batch ingredient, it contributes both protein and moisture to the finished product. These are tracked separately in formulation accounting.
3. South African commercial practice already uses up to 16% pork rind (as emulsion) in polony alongside separate batter-stage water. This is a demonstrated, commercially viable system, not a theoretical limit.

The Mapanda approach makes the skin emulsion at a defined water ratio, treats it as a finished ingredient, includes it at a defined batch percentage, and then adds whatever additional water the protein system can bind at the batter mixing stage. The two water additions are accounted for separately, within the finite capacity of the complete system.

6.4 The Mexican Research Tradition: Güemes-Vera, Yanez-Fernandez, and Totosaus

Mexican meat scientists have investigated pork skin collagen as a functional ingredient in frankfurters and emulsified sausage products. The key reference for this document is:

• Güemes-Vera N, Chavez JF, Yanez-Fernandez J, Totosaus A (2018) Frankfurter sausage texture is affected by using isolate, concentrate and flour of Lupinus albus and pork skin proteins. Food Research 2(3): 234 to 239 [19].

Güemes-Vera et al. (2018) prepared collagen solutions from pork skin at concentrations of 0%, 1%, 2%, and 3% and added these solutions directly to frankfurter batters alongside Lupinus flour, isolate, and concentrate at various levels. Their findings:

• A significant decrease in Warner-Bratzler firmness was observed in frankfurters supplemented with 3% collagen solution prepared from pork skin, relative to control.
• The collagen solution functioned as a water binder and contributed to emulsion stabilisation in the fine emulsion batter.
• The interaction between pork skin collagen and Lupinus proteins improved textural homogeneity compared to either ingredient alone.

The Mexican context is relevant to your Lagos system because it demonstrates that pre-extracted skin collagen solutions can be directly incorporated into fine emulsion batters as water-binding functional ingredients, and that their inclusion level and preparation conditions determine the textural outcome in the finished product. The Garcia-Garcia and Totosaus (2008) work on dietary fibres and emulsion stability in comminuted meat products is cited in the international literature [20] and confirms the Mexican research group’s engagement with collagen and texture in comminuted meat systems.

7. Standalone Preparation Recipes for Hautstoß and Sehnenstoß

These recipes produce pre-made emulsions that are treated as finished batch ingredients in the product formulations of Section 11. All water listed in these recipes is internal to the emulsion. Water added at the batter mixing stage (Section 11) is additional to and accounted for separately from the water used here, following the Mapanda framework [17, 18]. Section 9 sets out how these two water pools are managed within the finite total capacity of the finished product.

Hautstoß is the umbrella term used in this document for the heat cut, hydrolysed skin product, whichever species it comes from. Beef skin, pork rind and chicken skin are therefore three raw material variants of Hautstoß. Sehnenstoß is the umbrella term for the heat cut, hydrolysed connective tissue product, in this case Zebu shank and neck connective tissue. Table 5 and Table 6 below list beef skin, connective tissue, pork rind and chicken skin separately because their raw material properties differ enough to need separate recipes, even though beef skin, pork rind and chicken skin all fall under Hautstoß once processed.

7.1 Comparative Properties of the Four Emulsion Types

Property	Beef Skin Zebu	Connective Tissue Zebu	Pork Rind	Chicken Skin
Primary collagen type	Type I, III (dermis)	Type I, III (epimysium)	Type I, III (dermis)	Type I, III (dermis)
Fat content raw	5-15%	<5%	10-30%	35-50%
Pyridinoline crosslink density	High	Very high (shank/neck)	Low to moderate	Very low (broiler)
Optimal cooking temperature	95-98°C bag	95-98°C bag	90-95°C bag	60-70°C bag
Optimal cooking time	90-120 min	120-150 min	60-90 min	30-60 min
Gelatin set temperature (approx.)	25-30°C	30-35°C	23°C [1]	Lower than mammalian
Gelatin re-melt temperature (approx.)	47-52°C	50-55°C	47°C [1]	Lower than mammalian
Nebraska AW range tested	PCT: 100-600%; BCT: 100-600% [4,5,5b]	BCT: 100-600% [5, 5b]	PCT: 100-600% [4, 4a]	CCT: 100-300% [5a]
Recommended working AW in emulsion	200-300% (practical optimum)	200-300% (lower conversion)	200-300% [4a]	100-200% (fat limits AW)
Inclusion in sausage (as finished emulsion)	15-20% of batch	15-20% of batch	Up to 16% [17, 18]	5-10% of batch
Inclusion in patty (as finished emulsion)	40-55% of batch	20-30% of batch	20-30% of batch	10-20% of batch
Halal status	Yes	Yes	NO (pork)	Yes

Table 5. Comparative properties of four skin/Sehnenstoß types. Kulmbach data from [1]. Nebraska data from [4, 5, 4a, 5a, 5b]. Mapanda data from [17, 18]. The patty inclusion figures are the tested range, not a target: Formulation 1 in Section 11.1 uses 15%, well below the 40-55% ceiling, because a patty built mainly on emulsion rather than lean meat tastes and bites poorly, regardless of what the gel itself can structurally support.

Emulsion Type	Water added IN the emulsion(% of raw material weight)[Mapanda / Nebraska basis]	Salt(% of emulsion)	STPP(% of emulsion)	Approx. emulsion moisture(finished emulsion)
Beef Skin Emulsion (Zebu), reference only, not the current production route	200-300% AW on raw skin weight[Nebraska [4, 5b] practical optimum]	1.5-1.8%	0.25-0.30%	~70-75%
Beef Sehnenstoß Emulsion (Zebu), current production ratio	300% AW on raw CT weight (1 to 3, the current production ratio, within Nebraska tested range [4, 5, 5b])	1.5-1.8%	0.25-0.30%	~72-76%
Pork Hautstoß Emulsion, current production ratio	200% AW on raw rind weight (1 to 2, the current production ratio, within Nebraska and Mapanda tested range [4a, 17, 18])	1.5-1.8%	0.25-0.30%	~68-72%
Chicken Hautstoß Emulsion, current production ratio	150% AW on raw skin weight (1 to 1.5, the current production ratio, within Nebraska CCT tested range [5a])	1.0-1.5%	0.20-0.25%	~60-64%

Table 6. Water added within each emulsion type, with salt and phosphate blend (2:1 TSPP:STPP, per Section 10.2 [28]; the STPP column header reflects the historic single-salt figure this document has now replaced with the blend). These figures represent water added to the emulsion itself, not batter-stage water. All figures on raw material weight basis. Mapanda [17, 18] and Nebraska [4, 4a, 5, 5a, 5b] basis. Rows marked as the current production ratio give the fixed operating point now used in routine batches. The wider Nebraska and Mapanda ranges remain valid and are kept for reference.

7.2 Beef Skin Hautstoß (Zebu Lagos): Reference Recipe

Current production runs beef through the Sehnenstoß route in Section 7.3, using beef connective tissue rather than beef skin, at a fixed 1 to 3 ratio. This recipe is kept as a reference for operations that process beef skin directly, or that need beef skin data for comparison against the pork and chicken Hautstoß recipes in Sections 7.4 and 7.5.

Scientific basis: Kotter and Pralat, BAFF Kulmbach [1] (hot comminution, gel set/melt temperatures). Osburn and Mandigo, Nebraska [4, 5b] (BCT/PCT water binding; 200-300% AW practical optimum; 10-30% gel inclusion in finished product). Purslow [2, 3] (crosslink behaviour in mature bovine collagen).

Raw material specification

• Beef skin from Zebu carcasses: dehaired, washed, trimmed of excess subcutaneous fat. Acceptable residual fat: 5 to 15%.
• Skin from old nomadic Zebu animals: crosslink density is high. Use the longer boiling time.
• Do not use skin with heavy hair root contamination or with attached muscle that has not been trimmed.

Emulsion recipe: per 100 kg raw skin input

Ingredient	Quantity per 100 kg raw skin	Function / basis
Raw beef skin (pre-washed, trimmed)	100 kg	Collagen source
Water added to cooking bags (retained in full)	All bag liquid retained	Gelatin solution: counted as part of emulsion AW
Additional water added during hot mincing and bowl cutting	Net total: 200-300 kg(i.e. 200-300% AW on raw skin weight)Not all needs to be added at this stage: adjust to workable viscosity	Nebraska basis [4, 5b]: practical optimum 200-300% AW. At 200% AW, emulsion is firm and handleable. At 300% AW, emulsion is fluid and bowl-cut disperses easily.
Salt (NaCl)	1.5-1.8 kg (1.5-1.8% of emulsion)	Protein extraction, flavour, preservation
Phosphate blend (2:1 TSPP:STPP) [28]	0.25-0.30 kg b	pH adjustment, water inding improvement
Sodium erythorbate	0.05 kg	Antioxidant, colour protection

Table 7. Hautstoß recipe. Total emulsion yield: approximately 300-400 kg from 100 kg raw skin at 200-300% AW. This emulsion is then used as a batch ingredient in Section 11 at 15-55% of the final product batch depending on product type.

Step-by-step method

Step 1: Bag preparation. Place raw washed trimmed beef skin in sealed food-grade bags rated above 100°C. Maximum 15 kg per bag. Tie or clip firmly.

Step 2: Cooking. Water bath at 95 to 98°C. Cook for 90 minutes (trimmed Zebu skin, cleaner animals) to 120 minutes (heavily worked old Zebu cattle with high crosslink density). The bag internal temperature must reach 70°C and be sustained for at least 30 minutes per Nebraska minimum [4]. Do not allow bags to run dry.

Step 3: Open bags immediately. Retain ALL liquid. This is gelatin solution. Do not discard any of it.

Step 4: First grind hot. Pass hot skin and all cooking liquid through 4.5 mm immediately while above 60°C. The Kulmbach principle [1]: gelatin must remain fluid during comminution.

Step 5: Second grind hot. Pass through 3 mm immediately.

Step 6: Bowl cutting and water addition. Add hot minced skin mass to bowl cutter. Add salt and the dissolved phosphate blend [28]. Cut at medium speed 20 to 30 seconds. Begin adding ice water progressively to bring the emulsion down to 30 to 40°C while continuing to cut. Total water (bag liquid plus added ice water) should reach 200 to 300 kg per 100 kg original skin. Adjust to the upper end for a more fluid emulsion and the lower end for a firmer emulsion that handles better in a paddle mixer.

Step 7: Final temperature. Chill to below 12°C. The gelatin re-sets throughout the mass as it cools, forming a uniform gel.

Step 8: Use hot (preferred) or hold at 60 to 65°C for up to 4 hours, or refrigerate (do not freeze) and re-melt to above 50°C before use. Beyond 4 hours at 60 to 65°C, move the emulsion to refrigeration. Time and temperature control governs food safety here, not a cure addition; adding Prague Powder No. 1 to a standalone emulsion does not substitute for holding it correctly, and it introduces a nitrite contribution that would then have to be tracked and included in the final cured product calculation.

Kulmbach application [1]: Steps 4 to 6 implement the Heisschnitt principle. The gelatin must be mobile and fluid when it contacts the lean meat fraction. Cooling or freezing before grinding produces damaged gelatin particles that cold mechanical mixing cannot recreate as a continuous phase; complete remelting above the melt temperature can. Nebraska confirmation [4, 5b]: the 200-300% AW range was the practical working optimum across all three studies. The 600% AW maximum is achievable but produces an emulsion that is too fluid for easy handling in a paddle mixer; it is better suited to bowl-cutter or emulsifier incorporation in large batches.

7.3 Sehnenstoß (Lagos Zebu Beef)

Scientific basis: Kotter and Pralat, BAFF Kulmbach [1] (epimysial membrane processing). Osburn and Mandigo, Nebraska [5, 5b] (BCT at 100-400% AW; heating at 70°C for 30 min; inclusion at 10-30% in bologna). Purslow [2, 3] (very high crosslink density in Zebu shank and neck CT).

Raw material specification

• Source: sinew, heavy epimysium, fascia trimmed during carcass breakdown. Remove all bone fragments and cartilage (not hydrolysed under normal cooking conditions; produces hard particles).
• Remove clearly identifiable yellow elastic ligaments and other elastin rich tissue (for example the backstrap). Elastin does not hydrolyse to gelatin, and it is a separate tissue from the collagen rich silverskin this document treats as Salzstoß raw material elsewhere.
• Shank and neck CT: highest crosslink density; requires 150 minutes cooking. Loin and hip epimysium: 100 to 120 minutes.

Emulsion recipe: per 100 kg raw CT input

Ingredient	Quantity per 100 kg raw CT	Function / basis
Raw connective tissue (bone-free, elastin-trimmed)	100 kg	Collagen source
Bag cooking liquid (retained in full)	All liquid retained	Gelatin solution
Additional ice water added during hot mincing and bowl cutting	Current production ratio 1 to 3, 300 kg total AW	Current production ratio 1 to 3. Within the Nebraska BCT tested range of 100-400% AW [5, 5b]
Salt (NaCl)	1.5-1.8 kg	Extraction, preservation
Phosphate blend (2:1 TSPP:STPP) [28]	0.25-0.30 kg	pH, water binding
Sodium erythorbate	0.05 kg	Antioxidant

Table 8. Sehnenstoß recipe. Current production ratio 1 to 3 (300% AW), yielding approximately 400 kg from 100 kg raw CT. Use at 15-20% of sausage batch (as finished emulsion weight) per Nebraska inclusion study [5b].

Key difference from Hautstoß

Connective tissue requires a longer bowl-cut step (40 to 60 seconds versus 20 to 30 seconds for skin) because the fibrous residue from incompletely converted crosslinked collagen is more pronounced. The Kulmbach colloid grinder is the optimal tool for this step [1]. In its absence, extend the bowl-cut time and consider a third pass through a fine plate (1.5 to 2 mm) while still hot before the bowl cutter. For sausages, Sehnenstoß particles must reach below 0.5 mm. If 3 mm particles are visible in the emulsion, do not use it in fine emulsion sausages.

7.4 Pork Rind Emulsion (Schwarte-Emulsion, for non-halal production)

Scientific basis: Kotter and Pralat, BAFF Kulmbach [1] (pig skin gel set 23°C, re-melt 47°C; near-complete conversion). Osburn and Mandigo, Nebraska [4, 4a] (100-600% AW PCT gels; 10-30% inclusion in bologna). Mapanda et al. (2011, 2015) [17, 18] (100% AW rind emulsion used in South African polony at up to 16% batch inclusion). Güemes-Vera et al. Mexico [19] (pork skin collagen in frankfurter texture). NOTE: Pork rind emulsion is not permissible in halal products.

Mapanda protocol (2011, 2015)

The Mapanda protocol is the most directly applicable applied reference for a South African / Lagos production context:

• 7.5 kg raw rind cooked in 7.5 kg water (100% AW on raw rind weight) for 4 to 5 hours.
• After cooking, water was added back to make the total exactly 15 kg (maintaining 100% AW).
• Bowl-cut until a fine, sticky homogenous mass (rind emulsion) was formed.
• Cooled and vacuum-packed for use. (Note: the Mapanda laboratory protocol involved cooling and freezing for storage. For production, hot incorporation per Kulmbach [1] is preferred.)
• Incorporated at 0%, 8%, and 16% of the finished polony batch weight.
• Additional batter-stage water was adjusted independently per treatment to maintain target product weight and protein percentage.

The Nebraska approach for PCT [4a] tested higher AW levels (up to 600%) and found that 200 to 300% AW PCT gels incorporated at 10 to 30% of bologna batch produced the best textural outcomes. For the Lagos system, either the Mapanda 100% AW protocol or the Nebraska 200 to 300% AW protocol is acceptable; the Nebraska range produces a more fluid emulsion with higher water load already incorporated, while the Mapanda 100% AW produces a firmer emulsion.

Emulsion recipe: per 100 kg raw pork rind input

Ingredient	Quantity per 100 kg raw rind	Function / basis
Raw pork rind (dehaired, fat 10-15%)	100 kg	Collagen source
Bag cooking liquid (retained in full)	All liquid retained	Gelatin solution
Additional water (current production ratio 1 to 2, 200% AW. Mapanda basis: 100% AW. Nebraska tested range: up to 600% AW)	Current production ratio: 200 kg total AW (1 to 2 ratio on raw rind weight)Mapanda: 100 kg total AW (net add to reach 100%)Nebraska tested up to 600% AW	Current production ratio 1 to 2 [within Nebraska tested range, 4, 4a]. Mapanda 100% AW [17, 18]: firm, handleable emulsion, kept for reference. Nebraska tested up to 600% AW, not used in routine production.
Salt (NaCl)	1.5-1.8 kg	Extraction, preservation
Phosphate blend (2:1 TSPP:STPP) [28]	0.25-0.30 kg	pH, water binding
Sodium erythorbate	0.05 kg	Antioxidant

Table 9. Pork Hautstoß recipe. Current production ratio 1 to 2 (200% AW), yielding approximately 300 kg per 100 kg raw rind. Inclusion in polony/sausage: up to 16% of finished product batch weight per Mapanda [17, 18]; up to 30% per Nebraska [4a] if using higher AW gels.

Why pork rind is easier to work than Zebu beef skin: pig skin has near-complete gelatin conversion at equivalent boiling time because pyridinoline crosslink density is much lower [1]. The Kulmbach data shows pig skin gels at 23°C and re-melts at 47°C versus 25-30°C and 47-52°C for Zebu beef skin. Pig rind therefore disperses more easily, produces a more uniform emulsion, and requires less bowl-cut time.

7.5 Chicken Skin Emulsion (for halal all-poultry lines)

Scientific basis: Osburn and Mandigo, Nebraska [5a] (CCT at 100-300% AW; heating at 60°C for 30 min; 10-30% inclusion in reduced-fat bologna). Bekhit et al. (2022) [15] (chicken skin gelatin rheological properties). Mikulec et al. (2019) [16] (chicken skin gelatin vs bovine: lower water holding capacity). NOTE: Chicken skin emulsion is halal and suitable for all-poultry product lines.

Nebraska CCT findings (Osburn and Mandigo, 1998) [5a]

The 1998 Poultry Science paper established for chicken skin connective tissue (CCT):

• Optimal heating: 60°C for 0.5 hours (lower temperature than bovine skin because pyridinoline crosslink density in broiler skin is very low).
• AW range tested: 100, 200, and 300%. Gel stability confirmed across all three levels.
• Inclusion in finished product: 10 to 30% of total batch weight as finished CCT gel.
• CCT gels at 100 to 300% AW acted as practical water binders and texture modifiers in reduced-fat bologna.

The key constraint for chicken skin emulsion is not collagen crosslink density but fat content. Raw chicken skin has 35 to 50% fat. This high fat content limits practical AW to 200% maximum in the emulsion, because above this the fat-to-protein ratio produces emulsion instability during bowl cutting and during the thermal vulnerability window in the final product.

Emulsion recipe: per 100 kg raw chicken skin input

Ingredient	Quantity per 100 kg raw chicken skin	Function / basis
Raw chicken skin (fresh, chilled)	100 kg	Collagen and fat source
Bag cooking liquid (retained in full)	All liquid retained	Gelatin solution
Additional ice water (current production ratio 1 to 1.5, 150% AW)	150 kg total AW (current production ratio)	Current production ratio 1 to 1.5, within the Nebraska CCT tested range and below the 200% practical maximum set by fat content [5a]
Salt (NaCl)	1.0-1.5 kg (less than bovine: less protein to salt-extract)	Preservation, limited myofibrillar extraction
Phosphate blend (2:1 TSPP:STPP) [28]	0.20-0.25 kg	pH, water binding
Sodium erythorbate	0.05 kg	Critical: chicken fat oxidises rapidly

Table 10. Chicken Hautstoß recipe. Current production ratio 1 to 1.5 (150% AW). Cook at 60 to 70°C (lower than bovine skin, per Nebraska [5a]). Do NOT cook above 80°C: excessive fat rendering destabilises emulsion. Total yield approximately 250 kg from 100 kg raw chicken skin.

Why chicken skin emulsion has lower water holding capacity than bovine skin: measured water holding capacity is 3.8 to 5.6 mL per gram of chicken skin gelatin [16], compared to up to 600% AW on dry weight achievable with PCT and BCT [4, 5, 5b]. The Nebraska study [5a] confirmed that stable CCT gels were only achievable up to 300% AW, not the 600% achievable with PCT. For this reason chicken skin emulsion holds less water per unit weight than pork or beef skin emulsion.

7.6 Optional Transglutaminase Addition for Solid-Piece Applications

The recipes in Sections 7.2 to 7.5 produce a thermoreversible gel. The gel melts above its re-melt temperature and this is deliberate, because the standard use of Hautstoß and Sehnenstoß is hot incorporation into a batter or patty mix where the gelatin must still be fluid at the point of mixing, as set out in Section 3.1. Adding transglutaminase to this standard batch would defeat that purpose, since a crosslinked gel no longer re-melts.

A separate use case calls for the opposite property. Where Hautstoß or Sehnenstoß is used as a visible, shape-holding piece inside a formed or pressed product, for example chicken Hautstoß pieces set into a pressed ham, the piece needs to survive the product’s own final cook without melting back into a liquid phase. Transglutaminase gives the gel this property by crosslinking the gelatin network so that it no longer melts on reheating.

Add transglutaminase to the Hautstoß or Sehnenstoß as it cools through 40 to 50°C, at 0.5% of the emulsion weight. This 0.5% figure is the working dose for the specific commercial transglutaminase preparation used in this production system. Commercial transglutaminase preparations differ substantially in enzyme activity and carrier composition, so 0.5% of a different preparation will not necessarily deliver the same crosslinking effect. The transferable parameter is enzyme activity per gram and the supplier’s own recommended dosage for the intended application, not the percentage of powder addition as such. Confirm the dose against the specific product in use before applying 0.5% as a default. Mix gently for 2 to 3 minutes, enough to distribute the enzyme evenly without excessive shear. Hold the mixture at a temperature within this window, or slightly below it, for the crosslinking period recommended by the enzyme supplier, before moulding or before combining with other pieces. Once crosslinked and cooked, the piece keeps its shape through any further thermal processing the finished product receives.

Only use this transglutaminase step for emulsion destined for a solid-piece application. Keep the batches intended for hot incorporation into a batter or patty mix, as in Formulations 1 through 5, free of transglutaminase, since those systems depend on the gel remaining re-meltable.

8. The Kulmbach Hot Comminution Principle and the Process Error

8.1 What Kulmbach Established

The Kulmbach protocol [1]: comminute the skin in a colloid grinder, mix with water and additives, heat in a water bath to 72°C, centrifuge while still hot. The gelatin phase must be fluid at the moment of dispersion. The gel set temperatures documented by Kotter and Pralat are [1]:

• Pig skin: gels at 23°C, re-melts at 47°C.
• Bull epimysial membrane: gels at 32°C, re-melts at 49°C.
• Estimated Zebu beef skin: gels at 25-30°C, re-melts at 47-52°C.
• Estimated Zebu CT (shank/neck): gels at 30-35°C, re-melts at 50-55°C.

Once the gelatin sets below these temperatures, cold mechanical mixing cannot recreate the continuous phase. Complete remelting above the melt temperature can, per Section 8.3. This is the central Kulmbach principle.

8.2 The Lagos Process Error

What happened: boil, cool, freeze, bandsaw, mince cold, incorporate.

• Cooling: gelatin re-set below 32°C. Peak functional potential lost.
• Freezing: ice crystal formation damages the gel structure and promotes syneresis, producing a granular, crumbly, structurally weakened mass. Complete remelting can recover a working gel from frozen material, per Section 8.3, but the practical instruction is to avoid freezing skin or connective tissue between cooking and incorporation wherever the schedule allows it.
• Mincing cold: the mincer produced particles of damaged gelatin, not a continuous gelatin phase.
• The bandsaw was a workaround symptom. Hot skin does not need a bandsaw. The need for it was the diagnostic.

8.3 If Same-Day Hot Incorporation Is Not Possible

• Short hold (up to 4 hours): hold at 60 to 65°C in sealed containers in a bain-marie. Gelatin remains fluid; microbiologically safe.
• Overnight: refrigerate (do not freeze). Re-melt to above 50°C before use.
• Freeze-thaw: avoid entirely. If unavoidable, re-melt completely above 55°C and accept reduced functional performance.

9. Water Addition: The Correct Framework

9.1 Water Addition Cannot Be Calculated from a Single Fixed Capacity Ceiling

Total water addition is not governed by a single fixed capacity budget applied to the whole formulation. The Nebraska and Mapanda work demonstrates that water already incorporated into a preformed collagen gel can coexist with additional batter-stage water, treated as two separate pools rather than one shared allowance. It does not demonstrate that those two water pools are functionally independent without limit. The complete finished matrix still has a finite total water holding capacity, set by the combined protein, gelatin and hydrocolloid system present, and pushing either pool far enough eventually reaches that limit. This follows for three reasons established by the Mapanda and Nebraska research:

• The rind/skin emulsion water and the batter-stage water are independent contributions to the finished product, up to the combined capacity of the system. Mapanda adjusted batter-stage water independently of the emulsion water across nine different formulations [17, 18]. Within the ranges Mapanda and Nebraska tested, the two water pools did not compete for the same capacity.
• The water already bound inside the skin emulsion arrives in the final product as bound gelatin-phase water, not as free water that must be re-bound by the batter protein system. The Nebraska studies confirmed this [4, 5, 5b]: gel incorporation increased juiciness and did not compromise emulsion or cook stability in finished products at the tested gel inclusion levels.
• South African commercial practice already delivers products with 30% water extension in fine emulsion sausages using MDM, starch, and SPI as supporting water binders. This is a proven industrial system, again within a tested range rather than without limit.

9.2 How to Think About Water in This System

The correct mental model, based on Mapanda [17, 18] and the Nebraska body of work [4, 5, 4a, 5a, 5b]:

Step A: Make the skin emulsion with the chosen AW level. This emulsion has a defined moisture content. Call this the emulsion water.

Step B: Incorporate the emulsion into the final batter at the chosen inclusion percentage. The emulsion contributes its inherent moisture to the batch as bound gelatin-phase water.

Step C: Add batter-stage ice water over and above the emulsion. This additional water is bound by the combined capacity of the remaining protein network, primarily MDM and lean meat myofibrillar protein, per Section 2, with hydrocolloids or starch as optional additions only where Section 10.3 identifies a specific gap this protein network does not close.

The figures in Table 11 below refer to batter-stage ice water: water added over and above what was already in the skin emulsion.

9.3 Batter-Stage Water Limits: Over and Above Emulsion Water

Product / Formulation	Batter-stage ice water(OVER AND ABOVE emulsion water)	Supporting water binders required	Basis
Patty: 45% beef skin emulsion (200% AW), 18% lean beef, 18% MDM	10-20%	Starch 4-5%, methylcellulose 0.4%	Gelatin already bound in emulsion; batter water bound by remaining proteins and hydrocolloids
Patty: 40% beef skin emulsion, 20% lean, 20% MDM	15-20%	Starch 4%, carrageenan 0.3%, LBG 0.1%	MDM protein available for additional batter water binding
Sausage: 18% beef skin emulsion, 32% lean, 22% MDM	20-30%	Starch 2-3%, SPI 1.5-2%, carrageenan 0.4%	Comparable to Mapanda [17,18] and SA commercial 30% water Russian; myosin from lean meat is the primary binder
Sausage: 15% CT emulsion, 35% lean, 22% MDM	20-30%	Starch 2-3%, SPI 2%, carrageenan 0.4%	Same framework as above; Sehnenstoß brings less inherent water than skin at same AW
Reformed bacon: 18% skin emulsion, 42% whole muscle, 12% trim	10-15%	Starch 2.5%, SPI 2.5%	Whole muscle pieces limit total water uptake; tumbling increases brine uptake in muscle

Table 11. Batter-stage ice water (water added over and above the emulsion). Based on Mapanda [17, 18] (South African polony), Nebraska body of work [4, 5, 5a, 5b] (reduced-fat bologna), and SA commercial practice for Russian sausage extension. Compare with 200% ham where 100% of meat weight is added as brine/water.

The 200% ham parallel: in extended 200% ham, 100 kg of raw meat produces 200 kg finished product. The additional 100 kg is brine, water, and other ingredients. The protein system, myofibrillar proteins and phosphate, with a hydrocolloid such as carrageenan added only where testing shows it is needed, bears this load. Your sausage system with 18% skin emulsion plus 20 to 30% batter-stage water is operating on exactly the same principle. The skin emulsion water is already bound and does not compete with the batter-stage water for protein binding sites.

10. Functional Additives

Sections 10.1 to 10.4 document the functional additives available to this system, including cassava or potato starch and SPI. The formulations in Section 11 no longer include starch or SPI. Lean meat and MDM alone hold the water and binding load in those formulations, following the meat-only approach set out in Section 2. Starch and SPI remain valid, documented options and are kept here for reference, for anyone reintroducing them or comparing against a starch or SPI containing batch.

10.1 Salt

Mandatory at 1.6 to 2.0% NaCl of total batch (accounting for salt added to the emulsion). Extracts myosin from lean meat fibres; without adequate extraction, the sausage has no snap regardless of gelatin quality [6].

10.2 Phosphate Blend

Use tetrasodium pyrophosphate and STPP together rather than STPP alone. STPP does not act on muscle protein directly. It has to be broken down by meat enzymes into pyrophosphate first, and that conversion takes time, so a batch dosed with STPP alone is still building toward full activity through the early part of processing. Pyrophosphate is already in the active form and starts weakening the actin to myosin bond from the moment it dissolves. Combined, pyrophosphate extracts early while STPP is still converting, and STPP continues extracting through the rest of mixing, tumbling or resting as it breaks down, giving a wider window of activity than STPP alone for a small addition to ingredient cost [28].

Blend tetrasodium pyrophosphate and STPP yourself as food grade dry powders, starting at roughly two parts pyrophosphate to one part STPP, and treat this as a trial starting point rather than a fixed rule. Dissolve the blend completely in cold water before it meets the meat, since undissolved particles cause local protein coagulation and white streaking, and add it together with the salt at the start of mixing, tumbling or brine preparation, not partway through. Total inclusion across the recipes and formulations in this document runs 0.2 to 0.3% of batch weight, within the working range set out in [28]. Do not exceed 0.4%: soapy off-flavour results. Wherever “phosphate blend” appears in a recipe or formulation table in this document, it refers to this tetrasodium pyrophosphate and STPP combination, weighed and dissolved as described here, not to STPP used on its own.

10.3 Hydrocolloids

Salt and phosphate extract the muscle’s own myofibrillar protein, and that extracted protein gives a better texture and taste than an added gum, because a protein bound gel bites and tastes like meat where a hydrocolloid gel bites and tastes like a gel. Salt and phosphate are also the cheaper route, since they are already present in the formulation for curing, pH and flavour reasons, while a hydrocolloid is a single purpose addition on top. Hydrocolloids are frequently oversold in meat processing as a substitute for real myofibrillar protein extraction, when what they typically deliver is a different, weaker form of water holding at a materially higher ingredient cost [28]. For this reason, this document keeps hydrocolloids out of a formulation wherever salt, phosphate, the myofibrillar protein already present, and the Klebemasse, Salzstoß, Hautstoß or Sehnenstoß system already documented can do the job on their own. Where a hydrocolloid is kept, Section 11 states the specific structural gap it closes that the meat protein and gelatin system cannot close by itself, and it is kept at the lowest concentration that closes that gap, not at a concentration chosen to compete with a purchased functional blend.

Kappa-carrageenan at 0.3 to 0.5%: gels strongly with water and meat proteins on cooling; improves sliceability [9]. Include only where Section 11 identifies a specific gap that salt, phosphate and the existing protein and gelatin system do not close.

Locust bean gum at 0.1 to 0.2%: synergy with carrageenan; increases combined gel strength. Include only alongside carrageenan, and only under the same condition.

Methylcellulose gels on heating, not cooling, which is what would make it useful for bridging a 47-65°C thermal vulnerability window in a gelatin-dominant product, the range where a Hautstoß or Sehnenstoß gelatin phase is liquid and the myosin gel has not yet fully set. Reliable gelling for this function needs 0.3 to 0.5%. Below approximately 0.2%, methylcellulose is unlikely to form a functional gel at all, so a dose chosen for affordability rather than function risks paying for the ingredient without getting its effect. Methylcellulose is also one of the more expensive functional additives in this document’s ingredient set. This document avoids the trade-off entirely rather than resolve it with an unaffordable dose: Formulation 1 in Section 11.1 is built as a myofibrillar-protein-dominant patty, following the same framework as Formulations 2 and 3, so the thermal window is covered by the myosin gel already forming from the lean beef and MDM, and methylcellulose is not required. Where a formulation is deliberately built gelatin-dominant for some other reason and a genuine thermal gap remains, either fund the full 0.3 to 0.5% dose or increase the lean meat or MDM fraction until the gap closes, rather than include methylcellulose at a token, sub-functional level.

Cassava or potato starch at 2 to 6%: gelatinises above 60°C; permanently binds free water; reduces purge. Mapanda used 8% tapioca starch [17, 18]. Not used in the formulations in this document, per Section 11.

10.4 Soy Protein Isolate (SPI)

At 1.5 to 2.5%. Significant additional water binding at low cost. Mapanda [17, 18] used soy flour at 4 to 8%; SPI provides higher protein density at lower inclusion levels. Critical in high-MDM formulations where myosin gel functionality is partially reduced by mechanical denaturation.

11. Validated Product Formulations

All formulations below use the finished skin emulsions from Section 7 as pre-made batch ingredients. Salt and phosphate blend quantities are expressed as additional to what was added in the emulsion; the batch totals for salt and phosphate blend are given as notes. Batter-stage water is as defined in Section 6: over and above the water already in the emulsion.

11.1 Formulation 1: Hautstoß Burger Patty

System: myofibrillar-protein-dominant, following the same framework as Formulations 2 and 3, per Section 3.2. Paddle mixing only. 3 mm particle size throughout. No soy isolate or starch. Lean beef and MDM supply the primary protein structure and the water and binding load, with the Sehnenstoß in a supporting role for juiciness and cost.

A patty built mostly on real lean beef, with MDM and the Sehnenstoß in supporting roles, tastes and bites like meat and keeps enough myofibrillar protein to hold its own structure through cooking without needing a hydrocolloid to bridge the gelatin’s thermal weak point.

Ingredient	Inclusion %	Notes
Lean beef trim 80/20, minced 5 mm	50%	Primary myofibrillar protein source; supplies the patty’s meat flavour and bite
Beef or chicken MDM	20%	Emulsification capacity, protein supplement, cost reduction
Beef Sehnenstoß emulsion (Section 7.3, 300% AW, current production ratio, hot)	15%	Juiciness and cost reduction; a supporting phase, not the dominant structure; has ~74% moisture inherently
Batter-stage ice water (OVER AND ABOVE emulsion water)	11-14%	Total batter moisture rises accordingly; adjust within range
Salt NaCl (additional, in batter)	1.4% (emulsion contributes ~0.23%: total ~1.6%)
Phosphate blend (2:1 TSPP:STPP) [28] (additional, in batter)	0.2% (emulsion contributes ~0.04%: total ~0.25%)
TOTAL	approx. 100%	Spice pack (1.1%, listed below) is outside this table; use the low end of the batter water range to accommodate it and keep the finished total at approx. 100%

Table 12. Patty Formulation 1. No methylcellulose required: at 50% lean beef and 20% MDM, myofibrillar protein rather than gelatin now holds the primary structure, so the myosin gel that begins forming above 50°C and continues setting through the 47-65°C range covers the thermal window that previously needed bridging, the same mechanism already relied on in Formulations 2 and 3. Kappa-carrageenan and locust bean gum are also not included by default; add either only if testing shows a specific gap beyond what the protein and gelatin system already close, at 0.3% carrageenan and 0.1% LBG. Spices: black pepper 0.20%, garlic powder 0.15%, onion powder 0.10%, sweet paprika 0.10%, coriander 0.10%, sugar 0.15%, Prague Powder No. 1 0.25%, sodium erythorbate 0.05%.

Process: salt + dissolved phosphate blend [28] to lean meat, paddle mix 3 minutes. Add hot Sehnenstoß. Add ice water progressively. Add remaining dry ingredients. Mix 8 to 10 minutes below 12°C. Form. Cook to 72°C internal.

11.2 Formulation 2: SA Russian / Hungarian Sausage (Pork Hautstoß)

System: myofibrillar-protein-dominant. Bowl-cut fine emulsion. Snap required. No soy isolate or starch. Lean pork trim is increased to hold the water and binding load that SPI and starch previously shared.

Ingredient	Inclusion %	Notes
Lean pork trim 80/20	35%	Primary myofibrillar protein source; snap; holds the water binding load in place of SPI and starch
Pork Hautstoß emulsion (Section 7.4, 200% AW, current production ratio, hot- incorporated)	15%	Gelatin support phase; juiciness; water already in emulsion
Chicken MDM	20%	Emulsification, cost reduction
Pork MDM	10%	Additional protein and emulsification
Batter-stage ice water (OVER AND ABOVE emulsion water)	15-18%	Reduced from the previous 20-25% range because SPI and starch no longer share the binding load; myosin from lean pork is now the only batter-stage binder
Salt NaCl (additional)	1.1% (emulsion contributes ~0.27%: total ~1.8%)
Phosphate blend (2:1 TSPP:STPP) [28] (additional)	0.17% (emulsion contributes ~0.045%: total ~0.3%)
Fat trim / balance	balance to 100%, including the spice pack below	Kappa-carrageenan and locust bean gum are not included by default. Lean pork trim at 35% plus the Hautstoß gelatin phase already supply the snap and sliceability these hydrocolloids would add; include them only if slice bind testing shows a specific gap, at 0.3-0.4% carrageenan and 0.1% locust bean gum, per Section 10.3

Table 13. SA Russian/Hungarian with pork Hautstoß. Batter-stage water is held below the previous South African commercial extension figure of 30% (MDM + starch + SPI) because starch and SPI have been removed. Lean pork trim is increased to 35% to keep myosin available for this water. If slice bind falls short at 15-18% batter water, reduce toward the lower end rather than reintroducing starch or SPI. Hydrocolloids are also withheld by default, per Section 10.3, since the myofibrillar protein and gelatin phase already present are expected to supply the required bind.

Spice pack: sweet paprika 0.40%, smoked paprika 0.20%, black pepper 0.20%, white pepper 0.10%, garlic powder 0.20%, coriander 0.15%, nutmeg 0.05%, allspice 0.05%, sugar 0.20%, Prague Powder No. 1 0.25%, sodium erythorbate 0.05%.

Process: add hot Hautstoß to bowl cutter first. Cut 20 to 30 seconds. Add balance salt and the dissolved phosphate blend [28]. Add cold lean pork, cut while adding ice water progressively to below 12°C. Add MDM, cure, spices. Stuff into sheep casing 22 to 24 mm. Cold smoke 55 to 60°C for 60 minutes. Cook-finish to 72°C internal. Shower cool immediately to below 10°C.

11.3 Formulation 3: SA Russian / Hungarian (Sehnenstoß)

No soy isolate or starch. Lean beef trim is increased to hold the water binding load, following the same approach as Formulation 2.

Ingredient	Inclusion %	Notes
Lean beef trim 80/20	38%	Primary myofibrillar protein, snap, and batter-stage water binding
Sehnenstoß 15% (Section 7.3, 300% AW, current production ratio, hot-incorporated, bowl-cut to <0.5 mm)	Gelatin s	upport phase
Chicken MDM	22%	Emulsification, cost reduction
Batter-stage ice water (OVER AND ABOVE emulsion water)	17-20%	Reduced from the previous 20-25% range because SPI and starch have been removed
Salt NaCl (additional)	1.1%	Total approx. 1.8%
Phosphate blend (2:1 TSPP:STPP) [28] (additional)	0.17%	Total approx. 0.3%
Fat trim / balance	balance to 100%	Kappa-carrageenan and locust bean gum are not included by default, for the same reason as Formulation 2: lean beef trim at 38% plus the Sehnenstoß gelatin phase are expected to supply the needed bind and slice on their own. Include only if testing shows a specific gap, at 0.3-0.4% carrageenan and 0.1% locust bean gum, per Section 10.3

Table 14. SA Russian/Hungarian with Sehnenstoß. Sehnenstoß must be bowl-cut to below 0.5 mm before use in fine emulsion sausages. If slice bind falls short at 17-20% batter water, reduce toward the lower end rather than reintroducing starch or SPI. Hydrocolloids are withheld by default for the same reason given in Formulation 2 and Section 10.3.

11.4 Formulation 4: Reformed Bacon (Sehnenstoß Binder)

No soy isolate or starch. Lean beef trim is increased to hold the water binding load that SPI and starch previously shared.

Ingredient	Inclusion %	Notes
Beef silverside or topside, whole muscle chunks 2-4 cm	42%	Whole muscle base; visible in slice
Lean beef trim	16%	Additional myofibrillar protein and water binding
**Sehnenstoß 18% (Section 7.3, 300% AW, current production ratio)*	Gelatin b	inder between chunks
Brine + additional batter-stage water (OVER AND ABOVE emulsion water)	20-22%	Tumbling brine + any free water addition
Salt NaCl (additional)	1.1%	Total approx. 1.8%
Prague Powder No. 1	0.3%	Cure, colour stability
Phosphate blend (2:1 TSPP:STPP) [28] (additional)	0.17%	Total approx. 0.3%
Smoke flavour	0.15%
Spices	0.45%
TOTAL	approx. 99.5%	Adjust brine to close

Table 15. Reformed bacon. Process: tumble whole muscle chunks with brine 2 to 3 hours at 4°C. Mix with hot Sehnenstoß. Fill moulds under pressure. Steam-cook to 72°C internal. Chill under pressure to below 5°C. Slice 3 to 4 mm cold.

11.5 Formulation 5: Reformed Bacon with Salzstoß Trim in Place of Part of the Klebemasse Fraction (Provisional)

Status: provisional. This formulation applies the bench observation set out in Section 4 [21]. It has not yet been confirmed by instrumental gel strength testing and should be run as a trial batch alongside a Klebemasse control before it replaces Formulation 4 in routine production.

Formulation 5 follows Formulation 4 in every respect except the glue component. Where Formulation 4 uses a separate clean meat Klebemasse addition to bind the whole muscle chunks together, Formulation 5 replaces that addition with silverskin and sinew trim collected during the same primal preparation, comminuted through a 3 mm plate and paddle mixed cold with salt for twenty minutes, following the Salzstoß protocol in Section 4.7 [21].

Ingredient	Inclusion %	Notes
Beef silverside or topside, whole muscle chunks 2 to 4 cm	42%	Whole muscle base, visible in slice
Lean beef trim	14%	Additional myofibrillar protein and water binding
Salzstoß trim (silverskin and sinew from primal preparation, 3 mm plate, salted cold, paddle mixed 20 minutes)	4%	Rigidity and glue, replaces separate Klebemasse addition, per Section 4
Sehnenstoß (Section 7.3, 300% AW, current production ratio)	18%	Gelatin binder between chunks
Brine plus additional batter-stage water (over and above emulsion water)	13%	Tumbling brine plus any free water addition; reduced slightly because SPI and starch have been removed
Salt NaCl (additional)	1.1%	Total approximately 1.8%
Prague Powder No. 1	0.3%	Cure, colour stability
Phosphate blend (2:1 TSPP:STPP) [28] (additional)	0.17%	Total approximately 0.3%
Smoke flavour	0.15%
Spices	0.45%
Total	approximately 93%	Adjust Salzstoß trim yield and brine to close

Table 16. Reformed bacon with Salzstoß trim as the glue component, no soy isolate or starch. Process: tumble whole muscle chunks and lean trim with brine 2 to 3 hours at 4°C. Prepare Salzstoß trim separately by paddle mixing cold with its share of the salt for 20 minutes. Combine tumbled meat, Salzstoß trim and hot Sehnenstoß. Fill moulds under pressure. Steam cook to 72°C internal. Chill under pressure to below 5°C. Slice 3 to 4 mm cold. Compare slice cohesion against a Formulation 4 control batch before adopting this formulation in routine production.

11.6 Formulation 6: Pressed Ham with Chicken Hautstoß Pieces

This formulation follows a Central European Pressschinken method: injection, overnight rest, coarse mincing, and an internally generated Klebemasse fraction, rather than a separately sourced clean trim addition. It uses TG-set chicken Hautstoß pieces, prepared per Section 7.6, as a distinct visible component. No soy isolate or starch, and no water beyond the injection brine.

Ingredient	Inclusion %	Notes
Pork leg or shoulder, injected to 130% (30% pump) with brine holding salt, cure and phosphate blend, rested overnight, minced with a kidney plate	84%	Injected to 130% of green weight with brine holding salt, Prague Powder No. 1 and the phosphate blend, per Section 10.2; this figure is the combined pork and brine mass, and holds all of the batch’s water
Chicken Hautstoß (Section 7.5, 150% AW, current production ratio, TG-set per Section 7.6, diced)	15%	Visible, shape-holding piece; TG-set per Section 7.6 so it survives the final cook without melting; diced into pieces before combining
Sodium erythorbate	0.05%	Antioxidant
Spices	0.5%
TOTAL	approx. 99.5%

Table 17. Pressed ham with chicken Hautstoß pieces, built on an injected and internally generated Klebemasse method. No separate Klebemasse ingredient and no separate batter-stage water: the 30% pump brine supplies the entire water content, and the Klebemasse fraction is produced from within the pork itself rather than added as separate clean trim. Process: prepare chicken Hautstoß per Section 7.5, add transglutaminase per Section 7.6 as the emulsion cools through 40 to 50°C at 0.5% of the emulsion weight, cast into sheets, cold-set at 2 to 4°C, then dice into pieces. Inject the pork leg or shoulder to 130% of its green weight (a 30% pump) with a brine holding salt, Prague Powder No. 1 and the dissolved phosphate blend, at the strength needed to reach target levels in the finished, pumped product, per Section 10.2. Rest the injected pork overnight under refrigeration at 2 to 4°C to let the brine equilibrate through the muscle. Mince the rested pork through a kidney plate for a coarse grind. Take 15% of this coarse-ground pork by weight, pass it through a 3 mm plate, and paddle mix it cold on its own until a sticky myosin exudate forms, the Klebemasse texture set out in Section 2.1. Recombine this Klebemasse fraction with the remaining 85% coarse-ground pork and paddle mix the whole batch to an extremely tacky consistency. Fold in the diced, TG-set chicken Hautstoß pieces gently, enough to distribute them without breaking them down, since the tacky pork mass has already formed by this point. Fill moulds under pressure. Steam-cook to 70°C internal. Chill under pressure to below 5°C. Slice cold.

12. Why 100% Hautstoß Cannot Replace MDM in Sausages

Gelatin does not form an elastic heat-set gel. It forms a thermoreversible physical gel that melts above 47 to 52°C. A sausage cooked to 72°C passes well beyond this point. At 72°C a gelatin-only system is liquid: the sausage collapses.

The snap of a cooked sausage comes from the irreversible heat-set gel formed by myosin above 50°C [8]. Once set, the myosin network is permanent. Gelatin and myosin are thermally complementary: cold gelatin provides cold-state cohesion and juiciness; hot myosin provides cooked-state structure and snap. Neither can replace the other.

The minimum lean meat fraction for acceptable snap is 25 to 30% of total batch weight [7]. MDM contributes myosin at reduced functionality due to mechanical denaturation during deboning [7]. This is why the sausage formulations maintain at least 30 to 35% lean beef trim alongside MDM.

13. Frying Behaviour and Non-Stick Property

Both skin and connective tissue systems produce non-stick frying behaviour when correctly formulated. The gelatin phase melts at the frying surface, flows to form a thin continuous film between patty and pan, then sets rapidly against the cooler pan surface to create a smooth low-friction interface.

This fails and produces sticking when: total moisture is too high (excess free water produces steam that lifts and collapses the surface film before the myosin gel or, where funded, methylcellulose can set), fat content is too low (minimum 10 to 12% batch fat), or the patty surface is too cold when placed in the pan.

In Formulation 1, combined fat from lean trim (20% fat in 80/20 trim, at 50% inclusion), MDM (13 to 15% fat, at 20% inclusion), and Sehnenstoß (~5 to 8% residual fat, at 15% inclusion) produces approximately 13 to 14% batch fat, within the acceptable range.

14. Experimental Project: Klebemasse as a Surface Seal Before Drying and Smoking

Status: experimental. Nothing in this section has been tested. It is recorded here as a proposed trial, not as a validated method, and should be treated as provisional until weight loss data confirms it.

The idea is to coat the exterior of whole muscle pieces, bellies and pork legs, with a thin layer of Klebemasse during tumbling, before drying, thermal processing and smoking, to reduce weight loss during these stages.

The mechanism this idea rests on is established elsewhere in food science, even though it has not been tested for this specific purpose. Salt extracts myofibrillar protein from the meat surface during tumbling, exactly as it does inside a Klebemasse batch, per Section 2.1. Left to stand, this extracted protein forms a tacky surface film, the same pellicle formation used before smoking fish and some cured meats to help smoke adhesion and give the surface a set skin. A continuous myosin film at the surface, once it sets on the early part of the thermal process, could plausibly slow moisture migration out of the product during the drying and smoking stages that follow, in the same way a collagen casing or a natural pellicle reduces surface moisture loss.

Suggested procedure

• Prepare Klebemasse separately: clean lean pork trim, free of skin and silverskin, minced through a 3 mm plate, salted at 2.0 to 2.5% of the Klebemasse fraction weight, paddle mixed cold until a sticky exudate forms, per Section 2.1.
• Add the Klebemasse to the tumbler at 3% of total batch weight, toward the end of the tumbling cycle, so that it coats the exterior of the bellies or legs rather than mixing through the interior.
• Hold the coated pieces under refrigeration for a short set period, 2 to 4 hours at 2 to 4°C, before moving to drying, thermal processing or smoking, to allow the surface film to firm before it meets heat.
• Weigh a coated batch and an uncoated control batch of matched starting weight before drying or smoking begins.
• Weigh both batches again after drying or smoking, and again after any subsequent thermal processing step, recording weight loss as a percentage of starting weight at each stage.
• Inspect both batches for surface appearance, smoke colour uptake, and any effect on slice bind at the very outer edge of the product, since a firm surface film could also change texture at the rind.

Expected benefits, if confirmed

• Reduced weight loss during drying, thermal processing and smoking, which is the primary hypothesis being tested.
• More even smoke colour development, if the surface film gives the smoke a more uniform protein surface to bind to than bare fat or skin.
• A small additional yield gain at low cost, since 3% Klebemasse is a minor addition relative to the whole muscle weight.

None of these benefits should be assumed until the weight loss data from a coated batch is compared against an uncoated control under the same drying, thermal processing and smoking conditions.

15. Technical Conclusions

• Hautstoß and Sehnenstoß are standalone pre-made intermediate ingredients, distinct from raw, cold Salzstoß trim. Their internal water is separate from batter-stage water. The two water additions are accounted for separately, within the finite capacity of the complete system, following the Mapanda (2011,
  • framework [17, 18].
• The Kulmbach Heisschnitt principle (Kotter and Pralat, BAFF Kulmbach, 1981 [1]) applies to all four emulsion types. Hot comminution is mandatory: the gelatin phase must be fluid at the moment of dispersion into the batter.
• The Nebraska body of work (Osburn and Mandigo, 1996 to 1999 [4, 5, 4a, 5a, 5b]) establishes that PCT and BCT gels at 200 to 300% AW, incorporated at 10 to 30% of total batch weight, are viable water binders and texture modifiers in finished comminuted products. This is the practical working range for your system.
• Batter-stage ice water additions of 20 to 25% in emulsified sausages with 15 to 18% Hautstoß are consistent with: (a) South African commercial Russian sausage production at 30% water extension; (b) Mapanda’s variable batter-stage water across nine polony treatments; (c) the general 200% ham principle that the protein system determines water limits, not a fixed total water budget.
• Water addition figures in Section 9 (Table 11) refer explicitly to batter-stage water over and above the emulsion water.
• The Mexican research of Güemes-Vera, Yanez-Fernandez, and Totosaus [19, 20] confirms that pork skin collagen solutions function as water binders and texture modifiers in frankfurter-type sausages in an applied Latin American production context, extending the international relevance of these findings.
• 100% Hautstoß cannot replace MDM in a sausage. The gelatin melts above 47 to 52°C. The sausage cook temperature of 72°C is above this melt point.
• Snap in a cooked sausage requires a minimum of 25 to 30% lean meat providing extractable myosin. No hydrocolloid or gelatin system can substitute for this.
• Salzstoß is a cold, raw process distinct from the heat cut Hautstoß and Sehnenstoß systems. Salzstoß trim always includes an adhering meat fraction, because silverskin and epimysium cannot be lifted cleanly off a primal, and this is why salt continues to serve a function in Salzstoß even though it does very little to the tendon and collagen fraction itself [2, 3, 21, 22, 23].
• Bench observations recorded over one month of production, published separately as Van Tonder (2026) [21], suggest that Salzstoß trim put through a fine plate may match or exceed the glue function of clean meat Klebemasse, in addition to its established rigidity function. This finding is supported at the mechanism level by the restructuring literature on disrupted collagen and comminution surface area [22, 23, 24, 25, 26, 27], but the specific comparison between Salzstoß and Klebemasse has not yet been confirmed by instrumental testing and should be treated as provisional until it is.

References

All references are peer reviewed or from established applied meat science institutions, with the exception of reference 21, which is the authors’ own bench observation and is flagged as such wherever it is cited, and reference 28, a companion technical article by the same authors setting out the phosphate blend and hydrocolloid guidance used in Section 10. References 22 to 27 support the mechanisms discussed alongside reference 21 and are peer reviewed or from established institutional sources. Where reference 21 cites earlier work at second hand, for example Acton (1972) and Chesney, Mandigo and Campbell (1978) as reviewed in Zhuang and Zhou (2019), this document notes the secondary route rather than presenting it as a primary citation.

[1] Kotter L, Pralat A (1981) The properties of connective tissue membrane and pig skin as raw materials for cooked sausage. Meat Science 5(6): 397 to 413. Bundesanstalt fur Fleischforschung (BAFF), Kulmbach, Germany. https://pubmed.ncbi.nlm.nih.gov/22054490/

[2] Purslow PP (2005) Intramuscular connective tissue and its role in meat quality. Meat Science 70(3): 435 to 447. https://pubmed.ncbi.nlm.nih.gov/22063743/

[3] Purslow PP (2018) Contribution of collagen and connective tissue to cooked meat toughness: some paradigms reviewed. Meat Science 144: 127 to 134. https://pubmed.ncbi.nlm.nih.gov/29636208/

[4] Osburn WN, Mandigo RW (1996) Gelatinized high added-water pork skin connective tissue protein gels as potential water binders. University of Nebraska Swine Day Report. https://digitalcommons.unl.edu/coopext_swine/183/

[4a] Osburn WN, Mandigo RW, Eskridge KM (1997) Pork skin connective tissue gel utilization in reduced-fat bologna. Journal of Food Science 62(6): 1176 to 1182.

[5] Osburn WN, Mandigo RW (1996) Gelatinized high added-water beef connective tissue protein gels as potential water binders. University of Nebraska Animal Science Report. https://digitalcommons.unl.edu/animalscinbcr/485/

[5a] Osburn WN, Mandigo RW (1998) Reduced-fat bologna manufactured with poultry skin connective tissue gel. Poultry Science 77(10): 1574 to 1584. https://pubmed.ncbi.nlm.nih.gov/9776068/

[5b] Osburn WN, Mandigo RW, Calkins CR (1999) Utilization of desinewed beef connective tissue gel in reduced-fat bologna. Journal of Muscle Foods 10(1): 29 to 50.

[6] Offer G, Knight P (1988) The structural basis of water-holding in meat. Developments in Meat Science 4: 63 to 243.

[7] Xiong YL (2000) Protein functionality in comminuted meat products. ACS Symposium Series.

[8] Tornberg E (2005) Effects of heat on meat proteins. Meat Science 70: 493 to 508. https://www.sciencedirect.com/science/article/abs/pii/S0309174005000239

[9] Verbeken D, Neirinck N, Van Der Meeren P, Dewettinck K (2005) Influence of kappa-carrageenan on thermal gelation of salt-soluble meat proteins. Meat Science 70: 161 to 166.

[10] Foegeding EA, Larick DK (1986) Contributions of collagen to the properties of comminuted and restructured meat products. Reciprocal Meat Conference Proceedings 42.

[11] Chavez AJ, Henrickson RL (1986) Collagen as a hamburger extender. Journal of Food Quality 9(4): 275 to 285.

[12] Ambrosiadis I, Wirth F (1984) Comminution of connective tissue and temperature pattern in the manufacture of frankfurter-type sausages. Fleischwirtschaft 64: 68 to 72. [Kulmbach tradition]

[13] Hamm R (1972) Kolloidchemie des Fleisches. Paul Parey Verlag, Berlin. [BAFF Kulmbach foundational monograph]

[14] Haug IJ, Draget KI, Smidsrod O (2004) Physical and rheological properties of fish gelatin compared to mammalian gelatin. Food Hydrocolloids 18(2): 203 to 213.

[15] Bekhit AA, Hopkins DL, Gzhalytdinova MV, Bekhit AED (2022) Rheological and functional characterization of gelatin and fat extracted from chicken skin. Food Science and Nutrition 10(6). https://pmc.ncbi.nlm.nih.gov/articles/PMC9179164/

[16] Mikulec A, Kowalski S, Stachowiak B, Marzec A (2019) Chicken skin gelatine as an alternative to pork and beef gelatines. Potravinarstvo Slovak Journal of Food Sciences 13(1). https://potravinarstvo.com/journal1/index.php/potravinarstvo/article/view/1022

[17] Mapanda C (2011) Utilisation of pork rind and soya protein in the production of polony. MSc thesis, Stellenbosch University. Supervisors: Hoffman LC, Mellett FD. https://earthwormexpress.com/wp-content/uploads/2019/03/utilisation-of-pork-rind-and-soya-protein-in-the-production-of-polony-by-chrispin-mapanda-2011.pdf

[18] Mapanda C, Hoffman LC, Mellett FD, Muller N (2015) Effect of pork rind and soy protein on polony sensory attributes. Journal of Food Process Technology 6(2): DOI 10.4172/2157-7110.1000417. https://earthwormexpress.com/wp-content/uploads/2020/05/effect-of-pork-rind-and-soy-protein-on-polony-sensory-attributes.pdf

[19] Güemes-Vera N, Chavez JF, Yanez-Fernandez J, Totosaus A (2018) Frankfurter sausage texture is affected by using isolate, concentrate and flour of Lupinus albus and pork skin proteins. Food Research 2(3): 234 to 239. https://www.researchgate.net/publication/322530683

[20] Garcia-Garcia E, Totosaus A (2008) Low-fat sodium-reduced sausages: Effect of the interaction between locust bean gum, potato starch and kappa-carrageenan by a mixture design approach. Meat Science 78(4): 406 to 413. [Cited in international literature for Mexican comminuted meat research context]

[21] Van Tonder E (2026) Salzstoß: Rigidity That Also Glue. EarthwormExpress, 31 July 2026. [Authors’ own bench observation, one month of production work, not yet instrumentally validated. See Section 4.] https://earthwormexpress.com/salzstos-rigidity-that-might-also-glue/

[22] Light N, Champion AE, Voyle C, Bailey AJ (1985) The role of epimysial, perimysial and endomysial collagen in determining texture in six bovine muscles. Meat Science 13(3): 137 to 149.

[23] Gordon A, Barbut S (1992) Effect of chloride salts on protein extraction and interfacial protein film formation in meat batters. Journal of the Science of Food and Agriculture.

[24] Zhuang H, Zhou G (2019) Review of restructuring technology in meat products. Journal of Food Science and Technology. [Includes discussion of Acton (1972) and Chesney, Mandigo and Campbell (1978), cited here at second hand through this review, not from the original sources.]

[25] Strange ED, et al (1989) Contribution of collagen to the properties of comminuted and restructured meat products. American Meat Science Association, Reciprocal Meat Conference Proceedings.

[26] Food and Agriculture Organization. Small scale sausage production, chapter on comminution and protein extraction. fao.org.

[27] Development of the design of plate with variable diameters of holes and its impact on meat grinding quality and efficiency. Processes, 2024.

[28] Van Tonder E, Van Tonder-Berger C (2026) Salt, Phosphate and the Chemistry of Bind. EarthwormExpress, 4 August 2026. https://earthwormexpress.com/the-meat-factory/meat-science-research/salt-phosphate-and-the-chemistry-of-bind/

Document prepared for EarthwormExpress. All formulation data is based on peer reviewed science, with the single exception of the Salzstoß glue observation in Section 4, which is identified there and in reference 21 as the authors’ own bench observation awaiting instrumental validation. No ingredient quantities, temperatures, or functional claims are invented or extrapolated beyond published data or clearly flagged bench observation. All temperatures in degrees Celsius. Water addition figures in Section 9 and all product formulations refer to batter-stage water added over and above the water used in the Hautstoß or Sehnenstoß preparation. 7 August 2026.