Austrian butchery and the wider German speaking tradition both turn skin, sinew, membrane, and rind into useful sausage material. They do so by opposite means. One keeps the collagen raw and cold. The other converts it to gelatin with heat, a practice as old as brawn and head cheese. From one animal raw material, two different ingredients are made, each with its own function, by preparing it two different ways. The materials worth distinguishing are pork skin, chicken skin, beef skin, and beef connective tissue. We do not work with pork or chicken connective tissue, because they do not have nearly as much usable connective tissue as beef.
By Eben van Tonder and Christa van Tonder-Berger, 18 June 2026
EarthwormExpress, Applied Meat Science
Executive summary
Connective tissue, that is skin, rind, sinew, and membrane, is cheap and rich in collagen. Using it in sausage is old practice among butchers. The cooked collagen gel behind Sülze, Presswurst, and the Kochwurst class reaches back to medieval Europe. Helsinki measured its temperatures in 1981, and Nebraska measured its water binding in the 1990s.
Out of this come two ways of using the connective tissue, which do different jobs and work best in combination.
- The Salzstoß way. The connective tissue is kept raw and cold and added as an inlay. Native collagen binds water poorly, so it serves as a filler that gives bite and body.
- The rind, skin, or tendon emulsion way, the HeatCut Stoß. The connective tissue is cooked to gelatin, comminuted fine with water, and added back as a gel. Gelatin is a strong water binder, so it holds inexpensive added water in bound form.
- The combination. Snap comes only from the lean meat, never from collagen. Keep the lean meat high for snap, hold the cooked gel as a minority phase to bind the water, and use a little raw Salzstoß for body. Firmness and inexpensive water then come from two different proteins doing two different jobs.
Further findings supporting this:
- How readily the collagen converts depends on the raw material. Pork rind and chicken skin convert easily. Old beef sinew is hardest, because mature crosslinks accumulate with age. Beef carries more collagen than pork.
- Salt and phosphate have no functional effect on the gel or the stoss. Their work is on the binding of the meat. The organic acid in old recipes is a collagen pretreatment, useful for skin and young tissue, weaker on old beef.
- The article gives preparation guidance across young and old pork, beef, and chicken, and tests the combination against the LaBudde bind framework.
- We chose the names HeatCut Hautstoß for the skin gels and HeatCut Tendonstoß for the connective tissue gels to keep a link with the Austrian tradition, while the prefix HeatCut marks that the tissue was heated, cut, and made with added water. In the old language these are simply skin emulsions and tendon emulsions. The contribution is the naming, not a new process.
Using connective tissue in sausage is older than meat science. Sinew, muscle membrane, and rind are abundant, cheap, and rich in collagen, so every sausage tradition found a use for them. There are two methods. The Austrian Codex keeps the material cold and raw, in what it calls Salzstoß. The German speaking tradition, shared across Germany, Austria, and Switzerland, does the opposite and cooks the collagen-rich tissue until it turns to gelatin and sets as a binding gel. This hot route is the basis of brawn, Sülze, and the Kochwurst class. It reaches back to medieval rural Europe, where Sülze was a way to waste no part of the animal, and cooking the rind, grinding it fine, and mixing it into the batter to set on cooling is long recorded among butchers. The laboratory came later and measured it. Puolanne and Ruusunen at the University of Helsinki characterised the temperature behaviour of these gels in 1981, and Osburn and Mandigo at the University of Nebraska measured their water-binding capacity in the late 1990s. The two methods make the point clear: native collagen and gelatin are not the same ingredient.
The Austrian approach: Salzstoß as cold, raw collagen
The Österreichisches Lebensmittelbuch defines Salzstoß narrowly. It is the low fat connective tissue, the sinews and muscle membranes, that arises during the de-sinewing of meat, held in a salted state. The defining features are therefore three. The tissue is raw. It is salted. It is comminuted and incorporated cold.
In the Burenwurst, the sequence confirms this. The Brät is built first from meat and water, and only then is the Salzstoß, pre-ground to between two and three millimetres, added together with potato starch, after which the back fat is worked in. The connective tissue is never heated before incorporation, and it is never asked to bind water by itself. The binding work is done by the salt-soluble muscle protein in the Brät, where, under the influence of the salt, the protein passes into solution and later coagulates on heating into a network that holds the fat and the water. The Salzstoß in this scheme is an inlay and a structural filler. The native collagen contributes to bite and to yield, however it is not the functional water binder.
The tradition: cooked rind as a setting gel
The German speaking butcher has long known how to turn connective tissue into a binder. Scald or simmer rind and other collagen-rich parts until the collagen softens toward gelatin, then let it set. The set material has several names. A block of cooked, gelled rind is a Schwartenblock, also called Schwartengallerte. The Swiss Kümmelwurst uses both forms at once. Its base Brät is built from beef, sausage fat, Schwartenblock, and ice water, while scalded rind appears separately in the inlay with pork head and Sigelfleisch, the beef diaphragm. So one product uses cooked rind two ways, as a gelled binder in the Brät and as a visible scalded inlay.
The Kochwurst class is built on this method. These are precooked sausages whose ingredients are largely cooked before the sausage meat is made. The parts are held together by solidified fat in the spreadable Streichwürste, by gelatine in Sülze, the meat in aspic, or by heat-coagulated blood protein in Blutwurst. Unlike a Brühwurst, a Kochwurst does not stay solid when reheated but tends to liquefy, which is the signature of gelatin rather than a coagulated muscle protein network. Cooked rind also binds Presssack and Blutwurst, and a rind-rich batter canned on its own will set without added stock. This is the same chemistry the laboratory later measured.
The laboratory contribution: Helsinki and Nebraska measured an old method
The cooked collagen gel is old butchery. The medieval and early modern butcher cooked rind and head and trotters, released the gelatin, comminuted the softened tissue, and let it set to bind the product. Austrian teaching manuals list Sülzwürste as standard trade repertoire by the 1920s, and the Presswurst appears in the 1913 Codex and in Viennese accounts from the early nineteenth century. The laboratory added quantitative understanding. Puolanne and Ruusunen, working in 1981, comminuted pig skin and bull epimysial membrane, mixed them with water and additives, heated the mixture in a water bath, and centrifuged it while still hot. They established that as the temperature rose the bound water content fell while dissolved protein and gel strength increased, and they recorded the set and re-melt temperatures of the resulting gelatin. The liquid from connective tissue membrane gelled at about thirty two degrees Celsius and re-melted near forty nine degrees, while pig skin gelled at about twenty three degrees and re-melted near forty seven. They also found that, once the gelatin was correctly formed by hot processing, normal variation in salt, phosphate, added water, and pH did not greatly change its water binding or gel strength. This measured the physics behind a practice butchers already used, including the practical reason that the gel must be worked while warm, because it is fluid above its re-melt point and sets below it.
A systematic programme at the University of Nebraska then quantified how much water such gels can carry and at what level they can be used. Osburn and Mandigo worked across three raw materials, namely desinewed beef shank connective tissue, chicken skin connective tissue, and pork skin connective tissue. Their two 1996 reports established gelatinised high added-water pork skin and beef connective tissue gels as water binders. The 1997 Journal of Food Science paper, with Eskridge, applied a pork skin connective tissue gel in reduced-fat bologna. The 1998 Poultry Science paper extended the work to poultry skin connective tissue gel. The 1999 Journal of Muscle Foods paper, with Calkins, applied a desinewed beef connective tissue gel in reduced-fat bologna. Across these studies the gels were tested at high added-water levels and incorporated into finished product at roughly ten to thirty percent of batch weight, where they raised juiciness and acted as practical water binders without destabilising the product. The water already held inside the gel was carried into the finished product as bound water rather than as free water competing with the muscle protein system.
The same method appears, measured again, in the polony work of Mapanda, Hoffman, Mellett, and Muller, carried out at Stellenbosch University with Mapanda based at the Natural Resources Development College in Lusaka. Their starting material was pork rind, which is collagen protein and is added to formulations because it is cheaper, contributes to total meat, and contributes to the binding of water and fat. Because rind is tough, it was precooked, with roughly equal masses of rind and water held at cooking temperature for four to five hours, after which water was added back to restore the batch mass before chopping. This is not a cold inlay. It is the deliberate thermal conversion of collagen into a soft, water-holding gel before the rind ever enters the emulsion, exactly as the Schwartenblock is made, with the difference that the study measured the sensory and textural result.
The American restructured-meat literature explains why this works. Work in the Reciprocal Meat Conference proceedings reports that heating hide collagen for twenty minutes at sixty degrees Celsius, then adding it at modest levels to meat homogenates, improves the rheology of the mixture, and that gelatin and denatured collagen are strong water binders. The same work, by Kenney and colleagues, showed that collagen products including commercial gelatin and both raw and preheated epimysium improve the texture of precooked restructured beef. Native collagen binds water poorly. Once heat unwinds the triple helix toward gelatin, the same protein binds free water well.
The two methods assign water binding to different proteins
The two methods put the water-binding work on different proteins. In the Salzstoß tradition the muscle protein in the Brät is the binder, and the connective tissue is kept raw precisely so that it behaves as a defined, declarable inlay rather than as a gelatin source. In the rind-emulsion tradition the collagen is converted to gelatin so that it can itself bind water and stabilise fat, which allows it to substitute for a portion of more expensive lean meat. One method protects the integrity of the muscle protein system. The other recruits the connective tissue into the binding system by changing its chemistry.
Too much native collagen causes problems. The poultry and comminuted-meat literature shows that high levels of native collagen give poor emulsifying capacity, poor water holding, and gel pockets, because collagen behaves unlike myofibrillar protein. The Austrian method avoids this by keeping the Salzstoß proportion low and the binding load on the Brät. The laboratory method avoids it by hydrolysing the collagen first. Both manage the same risk from opposite directions.
| Feature | Salzstoß (Austrian Codex) | Cooked rind gel (German speaking tradition, measured by laboratory) |
|---|---|---|
| Tissue state | Raw, native collagen | Precooked, collagen converted toward gelatin |
| Temperature before use | Cold | Heated, for example four to five hours, or twenty minutes at sixty degrees Celsius for hide collagen |
| Salted before use | Yes, held in a salted state by Codex definition. The Codex sets no salt percentage for the material itself | Not inherently, salt optional |
| Inclusion in the original recipe | 20% Salzstoß in the Wiener Burenwurst, per the documented formulation | 10 to 30% gel in finished product, Nebraska and Mapanda |
| Primary water binder | Muscle protein in the Brät | The gelatinised collagen itself |
| Functional role | Inlay, bite, yield | Water and fat binding, lean substitution |
| Main risk managed | Avoided by limiting proportion and relying on Brät | Avoided by hydrolysing collagen before use |
Skin, rind, and tissue are not equal
The behaviour of a cooked collagen gel depends heavily on which tissue it is made from and on the age of the animal it came from. The governing variable is collagen crosslinking. When collagen is first laid down it carries immature, heat-labile crosslinks that break down readily on cooking, so the collagen converts to gelatin easily. As the animal ages, these convert to mature, heat-stable crosslinks, principally pyridinoline, and the collagen becomes both tougher and more resistant to conversion. Mature cow tissue shows the highest pyridinoline density and the highest thermal denaturation temperature, which is the direct measure of how stubborn the collagen is to cook down.
Beef and pork are not comparable here. Beef carries more collagen than pork in equivalent cuts, and in beef the crosslink content is positively tied to toughness. The meta-analysis of Li and colleagues found that in pork the same correlations were non-significant, though the authors note this is likely because few studies have examined pork rather than proof that no relationship exists. What is clear is that pigs are slaughtered young, so their collagen does not accumulate the mature crosslink burden of an old cow. The practical consequence is that pork rind is an easy, forgiving raw material that converts cleanly with heat alone, whereas beef, and old beef in particular, is the difficult case. Pork also simply yields less hard connective tissue than beef, so on a carcass the beef side is where both the abundance and the difficulty lie.
Chicken sits at the easy end. Broiler skin comes from very young birds and carries little mature crosslinking, so it converts quickly at low temperature, which is why the Nebraska poultry work used a gentler sixty degree extraction. Spent hen, the laying bird at the end of lay, is older and somewhat more crosslinked, yet even spent hen poultry tissue remains well below mature beef in crosslink density. The limiting factor with chicken skin is not crosslinking but its high fat content, which constrains how much water the gel can carry.
The role of pH and pretreatment
Salt, phosphate, and pH are often credited with the wrong job. In the final sausage, salt and phosphate are essential, however their work is on the muscle protein in the Brät, not on the collagen gel. Salt solubilises myosin and actin, and phosphate raises the pH away from the isoelectric point and dissociates actomyosin, which together extract the salt-soluble protein that binds water and sets on cooking. That is the binding system of the Brät. The cooked collagen gel is a separate matter. The measured finding from Helsinki is that once the gelatin has been correctly formed by hot processing, ordinary variation in salt, phosphate, and pH does not greatly change its water binding or gel strength. They have no functional effect on the gel or the stoss. Any salt added to the emulsion is for preservation and flavour, not to build the gel.
There is, however, one stage where pH does have a real effect on the collagen, and it explains the old recipes that use vinegar or another organic acid. This is pretreatment, the conditioning of the raw collagen before or during cooking. The gelatin industry has long worked with two routes. Acid pretreatment, the type A route, swells the collagen and loosens its crosslinks so the triple helix unwinds and converts faster and at lower temperature, and it is classically used for pork skin. Alkaline or combined treatment, the type B route, is the classic answer for tough, heavily crosslinked bovine material such as hide and bone. Acid pretreatment has been shown to improve the emulsifying stability of the resulting gelatin substantially, and the two routes yield structurally different gelatin, acid giving single peptide chains and alkaline giving double chains, with corresponding differences in solubility and function. The organic acid in an old rind emulsion recipe is therefore not seasoning. It is a conversion aid, and its value rises with the difficulty of the raw material.
This produces a simple rule of thumb. For easy materials, broiler skin and pork rind, heat and time are enough and acid is optional. For young beef, a mild acid pretreatment helps. For old cow skin and especially old cow sinew, the mature crosslinks resist simple acid swelling, so the better answer is longer and hotter extraction, or a combined approach, rather than relying on a splash of vinegar alone. There is no single best method, because the optimum tracks the crosslink density of the tissue.
Practical preparation across the range
The following starting points are written to work across young and old animals of each species. They are principles expressed as recipes, not laboratory-validated formulae, and the cooking times are the main variable to adjust for animal age. In every case the tissue is cooked until soft, comminuted while hot, and worked with water to a fine gel, then chilled or held warm for incorporation. Salt is given at a low preservation level, since the gel does not need it to set.
Pork rind, young or mature. Pork is forgiving. Wash and trim the rind, then simmer at about ninety to ninety five degrees Celsius for sixty to ninety minutes until fully soft, retaining all the cooking liquid because it is gelatin solution. Grind hot, then bowl-cut with added water to roughly one to two times the rind weight, with a little salt for keeping. Acid is generally unnecessary. Mature sow rind may need the longer end of the time range, however pork rarely poses a conversion problem.
Beef skin, young animal. Trim and wash, then cook at about ninety five to ninety eight degrees for ninety to one hundred and twenty minutes. A mild acid pretreatment, for example a short soak in dilute vinegar before cooking, will speed conversion and improve gel stability, though it is optional for younger animals. Retain the liquid, grind hot, and bowl-cut with water to two to three times the skin weight.
Beef skin and sinew, old working animal. This is the hardest case, typical of mature nomadic Zebu. The mature crosslinks resist conversion, so extend the cook to one hundred and twenty to one hundred and fifty minutes, or use pressure cooking to reach a higher temperature, which converts even heavily crosslinked collagen. For the hard sinew and shank tissue, a longer hot extraction is more reliable than acid alone, and the comminution must be finer and longer because unconverted fibrous residue is more pronounced. Bowl-cut to below half a millimetre if the gel is destined for a fine emulsion product.
Chicken skin, broiler or spent hen. Chicken converts easily but renders fat readily, so cook gently at about sixty to seventy degrees for thirty to sixty minutes and do not exceed eighty degrees, since excessive fat rendering destabilises the gel. Broiler skin needs the shorter time, spent hen the longer. Because chicken skin is fat-rich, hold the added water lower, around one to two times the skin weight, and use a little extra antioxidant, as chicken fat oxidises quickly.
How much emulsion, and how much water
There is no single universal threshold for how far the cooked gel can be pushed before firmness suffers, because the firmness of the finished product is set by the whole protein system, that is the lean meat fraction, the salt and phosphate, the quality of any mechanically deboned meat, and the supporting starch and hydrocolloids, rather than by one fixed water number. The published work provides a demonstrated working range and a firm floor on the lean meat side, and these together give a defensible compromise. The tables below set out the figures.
How much water the gel itself can hold depends on the raw material, and the figures are measured rather than estimated. Beef skin and pork skin gels were tested across one hundred to six hundred percent added water on the weight of the raw material, with a practical working optimum around two hundred to three hundred percent. Chicken skin is limited not by its collagen but by its high fat, which destabilises the gel above about two hundred to three hundred percent.
| Raw material | Practical working water | Maximum water extension (tested) | Limiting factor |
|---|---|---|---|
| Pork skin or rind | 200 to 300% | up to 600%, too fluid to handle well | handling, gel becomes fluid |
| Beef skin | 200 to 300% | up to 600%, too fluid to handle well | handling, gel becomes fluid |
| Beef connective tissue (tendon) | 200 to 300%, lower conversion | up to 600% on converted collagen | mature crosslinks, incomplete conversion |
| Chicken skin | around 200% | about 300% | high fat content destabilises the gel |
Per unit of raw material, pork and beef skin each hold roughly two to three times their own weight in water as a stable, workable gel, and up to six times at the unhandleable extreme. Chicken skin sits below the others. The ranking for water-binding capacity is pork skin and beef skin together and high, beef connective tissue similar but slower to convert, and chicken skin lower.
On inclusion level, the demonstrated figures are these. The compromise for a balanced product such as a polony or frankfurter is to keep the gelatin a clear minority phase while still extending the batch usefully.
| Source | Demonstrated inclusion (finished batch) | Note |
|---|---|---|
| Mapanda polony | up to 16% pork rind emulsion | commercially viable product |
| Nebraska bologna | 10 to 30% skin or connective tissue gel | no loss of stability |
| Suggested balanced product | 15 to 18% emulsion | above Mapanda, within Nebraska band |
The firmness limit is best read from the other direction, as a lean meat floor rather than a water ceiling. The water already inside the emulsion is bound and does not compete with the batter, so firmness is protected by defending the lean meat, not by capping total water.
| Quantity | Target for a balanced product | Reason |
|---|---|---|
| Lean meat | 30 to 35% minimum, floor at 25 to 30% | extractable myosin for snap |
| Gelatin emulsion inclusion | 15 to 18% | minority phase, carries bound water |
| Water in beef or pork skin emulsion | 200 to 300% | workable gel, high bound water |
| Water in chicken skin emulsion | about 200% | fat limits the gel |
| Batter-stage water | added over and above the emulsion | bound by lean meat, MDM, starch, protein additives |
Organic acid is a conversion aid, not a seasoning, and its value depends on the raw material. It swells the collagen and loosens the crosslinks, which helps most where the collagen is easy or moderate, and helps least against the mature crosslinks of old beef, where longer and hotter extraction is the better answer.
| Raw material | Organic acid pretreatment | Better alternative where acid is weak |
|---|---|---|
| Pork skin or rind | useful, classic type A route, speeds conversion | not needed, heat alone suffices |
| Chicken skin | optional, converts easily without it | gentle cooking, fat control matters more |
| Young beef skin | beneficial, speeds conversion and improves gel stability | longer cook if acid not used |
| Old beef skin and tendon | limited, mature crosslinks resist acid swelling | longer, hotter extraction or pressure cooking |
HeatCut Hautstoß and HeatCut Tendonstoß
Working in Nigeria, we prepared connective tissue gels of this type and gave them working names. The naming divides the material by its source. HeatCut Hautstoß, from the German Haut meaning skin, is the skin gel, covering chicken, beef, or pork skin. HeatCut Tendonstoß is the gel from the harder connective tissue, the sinew, epimysium, and fascia recovered during de-sinewing. The split is by raw material, skin on one side and connective tissue on the other.
The name echoes the Austrian Salzstoss tradition, since the material is the same family of de-sinewed connective tissue, while the prefix HeatCut marks that the tissue was heated, cut, and made with added water rather than used cold and raw. In the old language these are skin emulsions and tendon emulsions. The processing is the old method of cooking, fine comminution, and gel setting, the same operation behind Sülze and Presswurst, with the temperature behaviour measured at Helsinki and the water binding measured at Nebraska. The Nebraska work used the same split, pork skin and poultry skin connective tissue on one hand and desinewed beef connective tissue on the other. HeatCut Hautstoß and HeatCut Tendonstoß are not new emulsion types and not a new science. They are named instances of an old method, and the naming keeps the two raw material classes apart in a vocabulary a Central European butcher will know.
Proportion as a formulation choice
This is a matter of proportion, not process. In the classic hot collagen products, such as a bologna built largely on a connective tissue gel or a brawn set in its own gelatin, the gelatin is the dominant structure and the collagen gives the product its body. The alternative keeps the gelatinised connective tissue as a minority phase, about fifteen to twenty percent of the batch, while a larger fraction of lean meat, twenty five to thirty five percent, forms the dominant myosin gel and provides the snap. The cooked collagen then supports juiciness and yield while the muscle protein does the structural work, the same split of jobs seen in the cold Salzstoß Brühwürste, reached through a hot gel rather than a raw inlay. It is a choice about role and proportion, not a new technique, because the hot processing is the old method and the water-binding science is that measured at Helsinki and Nebraska.
Firmness and water binding
The two methods give different results in the finished product, because they leave the collagen in different physical states. The cold raw route keeps the collagen native. Native collagen binds water poorly, and at the cook temperature of a Brühwurst it does little binding, so it works as a firm particulate inlay that adds bite, body, and yield. In that route the firmness and the water binding both come from the muscle protein of the Brät, not from the connective tissue. The cold route does not extend a product with inexpensive water.
The hot cooked route converts the collagen to gelatin, and gelatin is a strong water binder that sets into a firm gel on cooling. This is the route that allows a large amount of added water to be carried economically, because the water is held as bound water inside the gel rather than as free water, which is exactly what the Nebraska high added-water gels showed. For cost management through water binding, the hot gel is the better tool by a wide margin. Its limitation is that gelatin cannot provide snap. It melts at the cook temperature and only re-firms as the product cools, so a product dominated by gelatin is soft and pasty rather than springy.
Firmness and water-binding economy are not in competition, because they come from two different proteins doing two different jobs. The snap and sliceability of a cooked sausage come from the irreversible myosin gel formed by the salt-soluble protein of the lean meat. A measured fraction of cooked collagen gel binds the extra water and adds juiciness, without providing structure. Keep the lean meat high enough to provide the snap, and hold the gelatin as a minority phase, so the inexpensive water is bound while the lean meat stays above the level the snap needs. Push the gelatin too high and it dilutes the muscle protein and softens the bite. Hold it in proportion and it pays for itself in yield while the myosin provides the firmness.
The bind framework and a worked formulation
The polymer and bind framework set out by LaBudde gives a way to test a formulation before making it. In that model the cooked sausage is a water-plasticized, filled-cell thermosetting biopolymer, in which the salt-soluble myofibrillar protein is the crosslinking polymer that forms the structure, while fats, carbohydrates, and connective tissue act as fillers. Fillers stiffen the matrix in compression, which is felt as body and chew, but they weaken it in tension and shear, which is what gives skin snap. The bind concept quantifies this. Bind is computed as the bind constant of the meat times its protein on a finished weight basis, and the functional targets are roughly two hundred to two hundred and twenty for beef products, one hundred and eighty to one hundred and ninety for mixed beef and pork, and one hundred and seventy to one hundred and eighty for pork-dominant products, with poultry variable. The bind comes from skeletal lean. Native collagen and other fillers contribute little or no bind, and LaBudde notes that the concept does not apply to such fillers.
| Product type | LaBudde bind target (finished weight basis) |
|---|---|
| Beef products | 200 to 220 |
| Mixed beef and pork | 180 to 190 |
| Pork dominant | 170 to 180 |
| Poultry | Variable, 170 to 180 for tight specifications, higher for lean chicken franks |
This framework sets the proportions for combining the two ways. The lean meat must provide the bind, because native connective tissue is a bind-neutral filler and contributes almost nothing to it. So the connective tissue is split between a small cold native fraction for body and a larger converted fraction that binds water as gelatin rather than diluting the protein, which is the Nebraska finding that the gel carries bound water rather than free water. A balanced formulation in this direction, suitable for a polony or frankfurter, runs approximately as follows. Lean meat at forty to forty five percent provides the bind and the snap, and is the single most important quantity to protect. Cold native Salzstoß is held to about eight to twelve percent, retained because the coarse inlay adds bite and a visible particulate body and stiffens the matrix in compression, but kept low enough that its filler dilution of the bind stays modest. HeatCut emulsion at fifteen to eighteen percent, made at two hundred to three hundred percent added water, carries the bulk of the connective tissue as a converted gel, holds a large share of the inexpensive water as bound water, and stays a clear minority phase. The remaining quarter to third of the batch is fat or mechanically deboned meat, starch at two to three percent, soy protein isolate at about two percent, salt at roughly one and a half to one and eight tenths percent of the total, and phosphate near three tenths of a percent, with batter-stage water bound by the lean and deboned meat protein together with the starch and isolate.
| Component | Share of batch | Function |
|---|---|---|
| Lean meat | 40 to 45% | Bind and snap, the dominant structural protein |
| Cold native Salzstoß | 8 to 12% | Filler that gives bite and visible body, stiffens in compression |
| HeatCut emulsion at 200 to 300% added water | 15 to 18% | Converted gel that binds inexpensive water as bound water |
| Fat or MDM, starch, soy isolate, additives, batter water | balance, about 25 to 30% | Fat, supporting water binders, seasoning |
Salt at roughly 1.6 to 1.8% of total and phosphate near 0.3% of total are included within the additives line. Figures are a sound direction within the demonstrated ranges, not a validated recipe.
This version meets all three goals at once. Firmness and snap are protected because the lean meat is back above its floor and remains the dominant bind polymer. Body and bite are retained through the modest native Salzstoß inlay, which the polymer model credits as compression stiffening. Cost reduction through water binding is delivered by the converted HeatCut emulsion and by the batter-stage water that the lean and deboned protein can hold. The inclusion levels sit inside the demonstrated Mapanda and Nebraska ranges. These percentages are a sound direction rather than a validated recipe, because the actual bind depends on the quality of the lean meat and the deboned meat and on the measured proximate analysis of the batch. The real proof is a bench trial in which the bind is calculated from the actual raw material figures and the cooked product is checked on a compression or torsion test of the kind LaBudde describes.
Conclusion
Salzstoß and the cooked collagen gel both make valuable sausage from low value connective tissue, and they differ on a point of protein chemistry. The Austrian butcher keeps the collagen raw and lets the muscle protein bind the water, so the connective tissue stays a controlled inlay. The German, Austrian, and Swiss maker of Sülze, Presssack, Schwartenblock, and Kochwurst cooks the collagen into gelatin and lets it bind water directly, so the connective tissue becomes a binder. Both methods reach back to medieval practice. Helsinki measured the temperature behaviour of the gel and Nebraska measured its water-binding capacity. We chose the names HeatCut Hautstoß and HeatCut Tendonstoß to keep a link with the Austrian tradition, while labelling them HeatCut to mark that the tissue was heated, cut, and made with added water. In the old language these are simply skin emulsions and tendon emulsions. The choice is not between two recipes but between two roles for the same protein.
Sources
- Österreichisches Lebensmittelbuch, Codexkapitel B14, Fleisch und Fleischerzeugnisse, definition of Salzstoß (B.2.3.3) and the Burenwurst production sequence, Bundesministerium traditional foods register.
- Puolanne, E., Ruusunen, M. The properties of connective tissue membrane and pig skin as raw materials for cooked sausage. Meat Science, 1981, 5(5): 371 to 382. University of Helsinki, Institute of Meat Technology. DOI 10.1016/0309-1740(81)90035-8.
- Osburn, W. N., Mandigo, R. W. Gelatinized high added-water pork skin connective tissue protein gels as potential water binders. University of Nebraska Swine Day Report, 1996.
- Osburn, W. N., Mandigo, R. W. Gelatinized high added-water beef connective tissue protein gels as potential water binders. University of Nebraska Animal Science Report, 1996.
- Osburn, W. N., Mandigo, R. W., Eskridge, K. M. Pork skin connective tissue gel utilization in reduced-fat bologna. Journal of Food Science, 1997, 62. Confirmed: gels formed by heating pork skin connective tissue at 70 degrees Celsius for 30 minutes, 100 to 600 percent added water, incorporated at 10 to 30 percent of batch.
- Osburn, W. N., Mandigo, R. W. Reduced-fat bologna manufactured with poultry skin connective tissue gel. Poultry Science, 1998, 77: 1574 to 1584.
- Osburn, W. N., Mandigo, R. W., Calkins, C. R. Utilization of desinewed beef connective tissue gel in reduced-fat bologna. Journal of Muscle Foods, 1999, 10: 29 to 50.
- Mapanda, C., Hoffman, L. C., Mellett, F. D., Muller, N. Effect of Pork Rind and Soy Protein on Polony Sensory Attributes. Journal of Food Processing and Technology, 2015, 6(2): 417. doi:10.4172/2157-7110.1000417.
- Mapanda, C. Utilisation of Pork Rind and Soya Protein in the Production of Polony. MSc thesis, Stellenbosch University, 2011.
- Contributions of Collagen to the Properties of Comminuted and Restructured Meat Products. Reciprocal Meat Conference Proceedings, American Meat Science Association, 1989, on heated hide collagen and the water-binding behaviour of gelatin and denatured collagen.
- Optimizing Utility of Low Water-Holding Capacity Meats. Reciprocal Meat Conference Proceedings, American Meat Science Association, 1995, reporting Kenney et al. (1986, 1992) on collagen, gelatin, and preheated epimysium in restructured beef.
- The Relationship Between Collagen Content and Emulsifying Capacity of Poultry Meat, on the poor emulsifying and water-holding behaviour of native collagen at high levels.
- Kulinarisches Erbe der Schweiz, Kümmelwurst entry, on the use of Schwartenblock in the base Brät and scalded rind and Sigelfleisch in the inlay.
- Kochwurst, general description of the precooked sausage class held together by solidified fat, gelatine in Sülze, or coagulated blood protein in Blutwurst, with reference also to Presssack and the self-gelling behaviour of cooked rind in traditional practice.
- Bundesministerium, Sulz und Presswurst entry, on the documented history of Sülzwürste in Austria, the 1913 Codex Presswurst recipe, and the standing of Sülzwürste in the Selcher trade by 1925.
- EarthwormExpress, study of brawn in European tradition, on the medieval rural origins of Sülze, the derivation of Sulza from the medieval term for salted water, and references to boiling collagen-rich parts in medieval cookbooks such as The Forme of Cury.
- Li, X. et al. Meta-analysis of the relationship between collagen characteristics and meat tenderness. Meat Science, 2022, on collagen content and pyridinoline correlating with toughness in beef but not significantly in pork, and on beef carrying higher collagen than pork.
- Roy, B. C. et al. Relationship between meat quality and intramuscular collagen characteristics of muscles from calf-fed, yearling-fed and mature crossbred beef cattle. Meat Science, on rising pyridinoline density and thermal denaturation temperature with cattle age.
- Purslow, P. P. Contribution of collagen and connective tissue to cooked meat toughness, some paradigms reviewed. Meat Science, 2018, including Avery et al. (1996) on the absence of a crosslink to toughness relationship in pork.
- Type A and type B gelatin: acid versus alkaline pretreatment of collagen, gelatin manufacturing literature, and goat skin gelatin study on acid pretreatment improving emulsion stability index.
- LaBudde, R. A. Review of comminuted and cooked meat product properties from a sol, gel and polymer viewpoint, 1992, on the water-plasticized thermosetting biopolymer model, the role of fillers in compression versus tension and shear, collagen contraction at its gel point, and the Saffle bind concept and its target levels. Reproduced on EarthwormExpress.