Salt is an essential ingredient in cheese making. This article is about salt’s function in cheese making, primarily: Moisture control, rind formation, control of production of lactic acid, texture improver, microbiological control, and flavour enhancer. Information on different salt types, and methods of applying salt is contained in other articles.
Salt is almost always applied to the cheese towards the end of the cheese making process. The earliest being after whey is drained from the curds as salting prior to this point will pre-maturely inhibit the growth of the starter culture.
Salt is commonly added as an ingredient in cheese making in four ways:
- Dry salt mixed directly into curds (Cheddar, Blue).
- Applied to, or rubbing rind with dry salt (Camembert, Brie).
- Brine soaking (Gouda, Edam, Havarti).
- Brine preserved (Feta, Halloumi).
Salt has many effects on the cheese, some immediate when applied, and some long term during aging. The amount of salt used and it’s different effects have significant influence on the cheese produced. Therefore the amount of salt used by one of the above methods should be accurately measured.
When salt is applied directly to the cut curds or to the fresh rind, it starts to dissolve into the water phase of the curd. This draws water in the form of whey to the surface of the curd. Depending on the method, this surface water (whey) is then either drained away if added to cut curds, or evaporated if applied to rind, or into the brine if brined.
Thus salt aids in dehydrating cheese to that cheese types required moisture content for proper development, thus in turn, each cheese type has a narrow required % salt content.
As moisture is diffused out of the curd’s surface from dry salting the curds or brining or evaporated off of the curd’s surface by dry salting a formed cheese, the surface of the cheese becomes dehydrated and the rind is formed.
The rind’s thickness and density can be controlled by varying the salting or brining conditions and the humidity and temperature during and after dry salting or brining.
In addition to a rind that is dehydrated, dry salting or brining of cheese results in a rind that is also of high salt content. This acts as a selective environment that strongly controls the microbiological activity on the rind. This is especially important for surface ripened cheeses such as Camembert and Brie.
Lactic Acid Production Control
For some cheeses, the addition of salt temporarily disrupts the starter culture’s fermentation into lactic acid. This can control the pH from becoming too low during pressing (if pressed) and the early stages of ripening.
As whey is lost due to salting, the whey carries out lactose, which if left can result in excessive lactic acid resulting in unwanted very low pH and unwanted fermentations during aging.
During early aging, loosely held water in the casein matrix becomes absorbed by the casein (the largest protein group in milk) resulting in a change from a moist curd to a drier softer more mellow cheese.
In general, the lower the salt content, the higher the number of microorganisms that can survive inside the cheese and conversely, the higher the salt content, the lower the number that can survive. Thus salting to the correct target % for the type of cheese is key to developing the cheese.
In addition, for some cheeses, salt also inhibits food poisoning microorganisms and thus is important for food safety.
Salt, first as normal has a savory, seasoning affect enhancing cheese’s flavour. Second via the Microbiological Control mechanism detailed above, changes a cheese’s flavour. If the salt content is not correct for the cheese type, these flavor compounds may not be produced in the right amount or ratio resulting in abnormal flavour for that cheese type.
In some highly salted cheeses such as Feta or Blue, the salt increases the action of lipase enzymes resulting in piquant flavour and aroma.