Almost all cheese is salted by one of three methods: before pressing as in Cheddar and American varieties, surface salting after pressing, or brine salting.
Purposes of Salting
- Promote further syneresis
- Slow acid development
- Check spoilage bacteria. Lactics are more salt tolerant than pathogens and spoilage bacteria.
- Promote controlled ripening and flavour development.
- Salty flavour
- Concentration 16 - 25% NaCl
20 kg cheese, 5 days or sometimes several weeks
3-5 kg, 24 h
250 - 350 g, 1 - 4 h
- New brine should be treated with about 0.1% of CaCl2 to prevent conversion of calcium and hydrogen caseinate to sodium caseinate. The latter has high water holding capacity, so the cheese takes up water from the brine and the cheese surface becomes soft and slimy.
- Brine pH should be adjusted to the pH of the cheese. Normally a pH of 5.2 - 5.6 is adequate.
- If the pH is too high, ion exchange causing sodium caseinate is encouraged.
- If the pH is too low, there is insufficient Ca/Na exchange and the cheese is too hard and coarse.
- Brine must be cleaned regularly by filtration, preferably microfiltered. UV sterilization combined with filtration is also used.
- Brine must be continuously agitated to prevent density fractionation (lower concentration brine on top) and dilution of the brine around the cheese.
- If cheese is floated rather than immersed in the brine, the exposed surface of the cheese should be dry salted.
- For vat salted cheese, uniform salt content depends on accurate estimate of the weight of unsalted curd, accurate weighing of salt, and consistent processing conditions.
- Salt uptake is:
- Increased by increased acidity (lower pH) at salting.
- Decreased by increased time between milling and salting due to healing of the cut surfaces on the curd particles.
- Increased by increased curd moisture content.
- Decreased for larger curds.
- For Cheddar and American varieties the salt content as a percent of moisture (S/M) should be greater than 4.0%.