Cheese sausage, cheese-filled roast and cheese salami share one problem: cheese melts at the temperature meat cooks at. The whole production technique exists to solve it.
Why does the cheese melt away?
Cheese melts in two stages.
First the fat melts; milk fat liquefies at 32 to 35 degrees.
Then the protein network loosens; casein bonds begin dissolving at 55 to 65 degrees.
Meat products are cooked to a core temperature of 72 degrees.
That temperature dissolves the protein network of most cheeses entirely.
The melted cheese flows and abandons the cavity it occupied.
What remains is a void and a pool of fat.
The cut face shows a hole where the cheese should be; the product fails on both appearance and texture.
The solution is choosing a cheese that resists melting, or delaying the melt.
Which cheeses suit?
Three properties determine a cheese's melting behaviour.
The first is pH. Cheeses with a lower pH melt less; acid tightens the casein network.
The second is moisture. Low-moisture cheeses are more resistant; water accelerates melting.
The third is calcium content. High calcium strengthens the protein bonds.
By those criteria the suitable cheeses are aged kaşar, tulum, aged white cheese and low-moisture mozzarella.
The unsuitable ones are fresh mozzarella, curd cheese, cream cheese and young kaşar.
Industrial production uses cheeses made specifically to withstand cooking; these are processed at a high curd temperature, which makes the protein network heat-resistant.
| Cheese | Melt resistance | Suitability | Note |
|---|---|---|---|
| Aged kaşar | High | Very suitable | Strong aroma |
| Tulum | High | Suitable | Salty, use sparingly |
| Low-moisture mozzarella | Moderate-high | Suitable | Neutral flavour |
| Aged white cheese | Moderate | Partly suitable | Can crumble |
| Young kaşar | Low | Unsuitable | Melts completely |
| Cream cheese | Very low | Unsuitable | Breaks the emulsion |
What piece size?
Size directly affects melting behaviour.
Small pieces heat quickly and melt completely.
Large pieces stay cool at the centre and partly hold their form.
The suitable range for cubes is 6 to 10 millimetres.
Below that they do not show on the cut face.
Above it they fall out during slicing and break the integrity of the product.
Cubes are preferred; they are more stable than spheres or irregular pieces.
Grated cheese should not be used; its surface area is too large and it melts entirely.
Some producers add the cheese frozen; that delays the onset of melting and leaves clearer pieces on the face.
Frozen cheese cubes go into the mixture last and at low speed.
When does it go into the mixture?
The order is critical in emulsion products.
In emulsion products such as salami and sausage the cheese goes in last.
Once the emulsion is complete the mixing speed drops and the cheese is mixed for thirty or forty seconds.
Cheese added at high speed breaks up and disperses into the emulsion.
The cut face then shows no pieces; the product carries only a faint taste of cheese.
In whole-muscle products the cheese is placed differently.
In roasts and smoked meat products the cheese goes between layers of meat and the product is rolled.
The cheese is better protected in that method; the mass of the meat slows the heat.
Even distribution must be ensured while filling the casing; cheese gathering in one area leaves a void there.
How is the water and fat balance kept?
Cheese brings both water and fat, and both affect the emulsion.
Kaşar is 40 to 45 percent water and 25 to 30 percent fat.
If cheese makes up 10 percent of the product, that means roughly 4 percent additional water and 3 percent additional fat.
That quantity shifts the water-fat balance of the emulsion.
The ice in the mixture is reduced to compensate.
The fat proportion is recalculated too, with the cheese fat added to the total.
Without that calculation the emulsion weakens and fat separates during cooking.
The cheese proportion is held between 8 and 15 percent of the product.
Above 15 percent the emulsion cannot carry it and the product falls apart when sliced.
How is the cooking adjusted?
The cooking curve is kept gentler for cheese products.
High heat melts the cheese rapidly and creates voids.
The start is 50 to 55 degrees; the product heats slowly.
It rises in steps to 70 degrees.
Once the core reads 72 degrees the cooking is ended.
Slow heating lets the cheese and the meat coagulate at the same rate.
A water bath or steam oven is preferred; dry heat burns cheese at the surface.
Rapid chilling afterwards is essential; in a slowly cooled product the cheese keeps flowing.
Once fully cold the product should rest at least twelve hours; the cheese firms again and slicing comes out clean.
How are the cut face and shelf life assessed?
Three checks follow production.
The first is voids. Ring-shaped gaps around the cheese mean the melt control failed.
The second is distribution. The cheese should be spread evenly across the face.
The third is adhesion. Bending a slice should not dislodge the cheese.
On shelf life the cheese brings a disadvantage.
Its water activity is higher than the meat's; those zones are more favourable to microbial growth.
Cheese products have a shelf life 20 to 30 percent shorter than their plain versions.
Vacuum packaging and an unbroken cold chain narrow that difference.
For sliced cheese products an opened pack should be used within five to seven days.
Freezing is not advised; the cheese releases water on thawing and the texture suffers.
