Why Do Cheese Curds Lose Their Squeak?

Cheese curds are small little pieces of cheese that are leftover from the process of making bigger pieces and anyone who has had them before know that one of their key characteristics, other than their small size, is their squeakiness. This type of cheese is most popular in the Midwest, certain parts of New York and Quebec and can be almost impossible to find anywhere else because it is best while fresh. That is because after a few days, the curds will lose their squeak and then they won’t taste as good either. There are many theories about why cheese curds lose their squeak but to understand the truth, you need to understand why they squeak in the first place.

Myth: Trapped Air

One of the most commonly heard reasons that cheese curds lose their squeak is that they lose air. This theory holds that it is air trapped within the curds which squeak but it seems that instead of being true, this was simply said by someone once upon a time and then the internet decided it was the truth. The reality is that if trapped air caused the squeakiness, there would be no way for it to escape and cause the curds to lose their squeak.

Why They Squeak

The real reason that cheese curds squeak comes down to science and their structure. Most people are aware that milk products, such as cheese, have protein and it is the structure of this protein that creates the squeak. Each curd itself is a combination of milk fat and casein protein that forms a protein matrix. While these molecules would stay in their matrix, their structure changes when they are exposed to rennet during the manufacturing process. That is because rennet eliminates the negative charge that some of the casein proteins have and this means that they are able to create long protein chains. It is these chains that create the squeak because they will rub against your teeth’s enamel.

Why They Lose Their Squeak

Cheese curds can lose their squeak over time for one of two reasons. The first is that during the manufacturing process they are salted, hooped and then pressed and each of these steps takes away some moisture. The process also causes the long protein strands to compress. This means that although they will still be long enough to squeak for a day or so, they won’t after that. The other option is that the curds were left unpressed but their acidity causes a low pH. The problem with the lower pH is that it breaks down the proteins so they are smaller and less likely to squeak.

How To Get The Squeak Back

This structure that causes cheese curds to lose their squeak is also why you can get the squeakiness back by microwaving them for a few seconds. When you microwave cheese curds, some of the moisture will go through hydrolysis so the molecules in the protein chain will drop their negative ions. This means that longer protein chains can be formed again and that can bring the squeakiness back.