Salt (sodium chloride, NaCl) has numerous functions and can be added to cheese several ways
Salting is an important step in the cheese making process. But then again, which step isn’t important? When one thinks about salt and cheese the first thing that may come to mind are the so-called “salty” cheeses; cheeses with a very prominent salty taste like Pecorino Romano, Mizithra, or Feta to name a few. Upon first glance, the salt content of cheese may seem to be of issue just for flavor. After all, we’ve all experienced the let-down of low-sodium products. While flavor is, no doubt, a major purpose of salt in cheese, there are a few other important functions as well.
The major functions of salt in cheese include:
- Regulating microbial growth: Salt acts as an anti-microbial agent to some degree. It can reign-in the growth of some microbes. This process can also allow more salt-tolerant microbes to grow since the playing field has been cleared.
- Encouraging moisture loss: Salt will draw whey (moisture) out of the cheese. This dries the cheese’s body and has pronounced effects on its texture and stability. The mechanism of moisture removal is covered in the next section.
- Altering texture: Salt can directly affect cheese’s body/texture by altering protein structure or indirectly by removing moisture. The presence of salt in certain concentrations can also change how microbes and enzymes behave, having drastic effect on texture, flavor, etc.
- Enhancing flavor: Salt not only gives cheese a salty taste, but can also help enhance other flavors present or cover up unpleasant ones.
As we’ll cover in the following sections, cheese makers have several methods they usually employ to introduce salt into cheese. No matter which method they choose, it involves salt pulling moisture out of the cheese and simultaneously allowing salt to diffuse into the cheese body. The exact mechanism can get a little complex and depends on many different factors, but it comes down to 2 main phenomena: osmosis and diffusion.
If you’d like the quick and dirty explanation: salt pulls moisture out of the cheese and the cheese then absorbs some of that salty water back in. The end result is drier saltier cheese. If you’d like to dive into the chemistry, read on…
Osmosis describes the motion of water molecules. Osmosis explains why salting cheese results in it losing moisture (expelling whey). By creating a large concentration of salt outside the cheese, moisture will want to migrate from the cheese to the salty outside. Think of a crowded room (cheese) of people (water molecules). The people (water molecules) will overflow into an adjacent room (cheese exterior) in order to get more space for themselves.
While all of this moisture loss is occurring, the cheese is also absorbing some of that salty water to some degree. This process is called diffusion. Salt molecules will spread out equally and creep into the cheese. This causes salt to enter the cheese body and permeate throughout its structure. It’s easy to see how confusing this whole process is since water is leaving the cheese all the while salt molecules are entering.Top
Cheese makers employ several different methods in order to accomplish what we talked about in the above section. The method used depends on a whole bunch of factors and the cheese maker/affineur need to use their expertise to determine which is best for their cheese.
Also called direct salting, the dry salting procedure involves sprinkling the cut-up curds with salt. After the coagulated milk has been cut, cooked, and drained, salt is applied. This method takes advantage of the large amounts of surface area that are exposed and allows for quick salt absorption and rapid whey/moisture expulsion. Cheeses like Cheddar, Colby usually use this method.
Whole wheels or blocks of cheese can be submerged in a salty brine solution. This method allows for the gradual penetration of salt and also aids in rind formation since the outer-most layer of the cheese will dehydrate to some degree. Cheeses like Mozzarella, Blue, some Alpine, and Feta use this method.
Dry Rub Salting
The last major method of salt addition involves applying salt to the exterior of already formed wheels/blocks of cheese. Usually salt is applied and can be scrubbed into the surface. This method doesn’t work so well with very large cheese formats so it’s reserved for smaller cheeses like some Alpine-style cheeses and Limburger.Top
For More Information
- International Journal of Dairy Technology - Salting and the role of salt in cheese
- Agroscope - SALT AND ITS SIGNIFICANCE IN CHEESE MAKING
- Fundamentals of Cheese Science - Salting of Cheese Curd