Buzz
The last one—“Is it mold?”—is amusing because it’s almost never mold. Common culprits include solidified, cooled oil, discoloration, and cheese flavor crystals. (Recently, someone found a white mass in a jar that seemed like a mouse, but we’re still waiting for confirmation from the experts.)
Putting questionable blobs aside, it's hard to imagine anyone criticizing cheese flavor crystals, though most of us never get to take Cheese Science 101 in school. So it’s no surprise that many of us can’t recognize calcium lactate or tyrosine crystals just by looking at them.
So, what exactly are these “cheese crystals”?
There are two primary types of flavor crystals you might find on cheese: Calcium lactate and tyrosine. While they don’t have their own flavor, their presence signals that the cheese has undergone some delicious transformations during aging, resulting in a more flavorful cheese.
What exactly is calcium lactate?
As stated on cheesescience.org, calcium lactate is a salt made up of a calcium ion and lactic acid, often found on cheddar cheeses—typically on the surface where moisture can accumulate:
As cheese matures, the culture breaks down the lactose, producing lactic acid. As the level of lactic acid increases in the cheese, it binds with calcium ions, forming calcium lactate. When calcium lactate levels rise enough, they will eventually crystallize, becoming visible as crystals.
The crystals appear powdery, and while they usually form on the exterior of the cheese, they can also appear inside. Storing cheese in loose packaging or exposing it to temperature shifts can promote the formation of calcium lactate crystals. However, there is no need to worry about their presence—your cheese is still perfectly safe to eat.
What are tyrosine crystals?
Tyrosine is an amino acid, a molecule that joins with others to form the chains that create proteins. When it crystallizes, it forms distinct white speckled clumps, often found in the holes of aged cheeses like gouda, or within a wheel of Parmigiano-Reggiano. These crunchy crystals indicate a breakdown of proteins, as explained by cheesescience.org:
Unlike calcium lactate,
which is attributed to internal factors in the cheese, tyrosine crystals seem to be connected to the action of the culture Lactobacillus helveticus. This microorganism is typically added to the mentioned cheeses to help create flavor. L. helveticus specializes in breaking down peptides (protein chains) into free amino acids, with tyrosine being one of them. As tyrosine accumulates, it will eventually form crystals, though the process is still not fully understood.
Unlike calcium lactate, how the cheese is handled and stored doesn’t appear to have much impact on the formation of tyrosine crystals. However, the presence of these crystals is a clear sign that your cheese has aged well, and is likely to be full of rich, savory flavor. So, if you spot tyrosine crystals on your cheese, celebrate, my friend!
