Article by Eben van Tonder. 26 January 2026.

Understanding pressure, perforation and lining in reformed products

Introduction

Bacon and ham are often discussed together because both may be cured, formed and cooked. Technologically, however, they behave very differently. The tools used to form them reflect this difference.

Confusion arises when bacon moulds are treated like ham presses, when compression logic is transferred from one product to the other, or when baking paper is used by habit rather than necessity. These errors lead directly to defects in texture, purge, slicing behaviour and frying performance.

This article clarifies the functional differences between bacon moulds and ham presses, explains why perforations matter, and sets out clear rules for pressure and lining in both systems. The focus is on reformed bacon, with specific reference to beef bacon.

Bacon

Shaping without compression

Reformed bacon moulds are shaping devices, not presses. Their purpose is to define geometry, stabilise the mass during cooking and allow controlled moisture and fat release. They are not designed to trap liquid, redistribute purge or apply sustained pressure.

This is confirmed by their construction. Bacon moulds are perforated on the base and often on the sides. These perforations exist for a reason.

• They allow water and melted fat to escape during cooking.
• They allow steam to vent rather than build pressure.
• They support clean surface protein setting.
• They promote surface drying rather than boiling.
• They enable later browning and crisping in the pan.

If compression were the objective, perforations would defeat it. Their presence confirms that the mould is intended to shape without squeezing.

Compression logic for bacon moulds

Because bacon moulds are perforated, compression must be minimal.

The objective during filling and closing is as follows.

• To remove large air voids.
• To ensure even contact with the mould walls.
• To preserve visible particle structure.

Excess pressure causes predictable failures.

• Protein squeeze out through perforations.
• Fat smearing against the walls.
• Loss of lean fat definition.
• Dense, rubbery bite.
• Dry or crumbly texture after frying.

Correct practice is straightforward.

• Hand pack firmly but gently.
• Close the lid until it seats.
• Do not force.
• Do not use forearms.
• Do not use tools.
• Do not re tighten during cooking.

Rule of thumb.
The mould should close comfortably with two hands. If liquid is forced out during closing, pressure is already too high.

If significant resistance is felt, the mix is overfilled or incorrectly structured upstream.

Baking paper in bacon moulds

Why it contradicts the design

In perforated bacon moulds, baking paper is technically contradictory.

Baking paper does the following.

• It blocks perforations.
• It prevents purge escape.
• It traps steam.
• It causes surface boiling instead of protein setting.
• It negates the entire drainage function of the mould.

Using baking paper inside a perforated bacon mould converts it into a poorly functioning steam box.

Correct release and hygiene are achieved through process control.

• Clean stainless steel.
• Correct protein extraction.
• Correct cooking temperature.
• Hot demoulding.

This applies to both pork bacon and beef bacon. It applies even more strongly to beef bacon made from aged meat, which is more sensitive to over compression and surface steaming.

Beef bacon

Why perforation and low pressure matter even more

Aged beef bacon differs materially from pork bacon.

• It has lower free water.
• It has higher protein density.
• It develops stronger binding once set.
• It is more sensitive to overworking.

Perforated moulds allow aged beef bacon to perform as intended.

• Clean protein setting.
• Controlled surface moisture loss.
• Retained internal juiciness.
• Sharp slicing behaviour.
• Frying without purge.

Blocking perforations or applying pressure destroys these advantages. For beef bacon, minimal pressure is not optional. It is essential.

Ham

Why presses exist and why pressure is used

Ham presses serve a different function entirely.

They are designed as follows.

• Solid rather than perforated.
• Intended to retain moisture.
• Intended to redistribute purge.
• Intended for cold slicing.

In ham production, pressure is applied deliberately.

• To eliminate voids.
• To bind whole muscles or large pieces.
• To create uniform slice faces.
• To support shape during full protein coagulation.

This is why traditional ham presses are often tightened firmly and sometimes adjusted during cooking.

In this context, baking paper or liners may be used.

• To assist demoulding of soft, high moisture products.
• To protect decorative shapes.
• To simplify cleaning.

Even in ham production, excessive pressure causes defects.

• Dense texture.
• Fat separation.
• Protein squeeze out.
• Excess purge.

Practical rule of thumb for ham presses.
Close firmly using arm strength only. Do not use tools. Stop when resistance becomes elastic rather than mechanical.

If closure requires body weight or tools, formulation or fill level is incorrect.

Key distinction

Why bacon logic must not be replaced by ham logic

Bacon moulds and ham presses exist for different purposes.

Bacon moulds.

• Are perforated.
• Release moisture.
• Shape without compression.
• Support later frying and crisping.

Ham presses.

• Are solid.
• Retain moisture.
• Compress deliberately.
• Support cold slicing.

Using ham press logic for bacon results in the following.

• Steaming.
• Smearing.
• Poor browning.
• Weak structure.

Using bacon mould logic for ham results in the following.

• Voids.
• Weak binding.
• Poor slice stability.

Once the distinction is understood, most processing problems disappear.

Conclusion

Perforated bacon moulds are designed to drain, not to compress. They must be closed lightly, used without liners and allowed to do the job they were engineered for.

Baking paper has no functional role in perforated bacon moulds and actively undermines product quality. Pressure beyond gentle shaping is not control. It is damage.

Ham presses exist for different reasons and should not be used as a reference point for bacon decisions.

For reformed bacon, whether pork or beef, structure comes from formulation and process, not force. Respecting the tool design is the first step to consistent quality.

References

• Feiner, G. (2006). Meat Products Handbook. Woodhead Publishing.
• Honikel, K. O. (2004). Water holding capacity of meat. Fleischwirtschaft International.
• Lawrie, R. A., Ledward, D. A. (2006). Lawrie’s Meat Science. Woodhead Publishing.
• Pearson, A. M., Dutson, T. R. (1994). Quality Attributes and Their Measurement in Meat, Poultry and Fish Products. Springer.
• Toldrá, F. (2010). Handbook of Meat Processing. Wiley Blackwell.
• Traditional Austrian and German meat technology manuals and professional butchery practice.