What Is This White Stuff on My Cheese?
One of my passions is a Facebook group called Food Ideas for Busy Moms by Trader Joe. Like any Facebook group, this one has a fair amount of drama and a few recurring themes: “Look at that bug I found in that grocery bag”, “Look at my sausage board”, and “Is this mold?” are a few of my favorite Facebook post genres that pop up daily.
The last one is “Is it mold?” — funny, because it’s almost never mold. Solidified, chilled oil; bleaching; and cheese-flavored crystals are the usual suspects. (More recently, someone found a white blob in a jar that turned out to be a mouse, but we’re still waiting for confirmation from the operator.)
Anyway. Questionable stains aside, it’s hard to see anyone regurgitate nasty cheese-tasting crystals, but few of us have the opportunity to take the Cheese Science 101 course in college, so it’s no surprise that most of us fail to identify calcium lactate crystals and /or tyrosine at a glance. .
What are these “crystals of cheese”?
There are two main types of taste crystals found in cheese: calcium lactate and tyrosine. None of these have a flavor of their own, but their presence indicates that the cheese has undergone some flavor changes during the aging process, resulting in a more flavorful cheese.
What is calcium lactate?
According to cheesescience.org , calcium lactate is a salt composed of a calcium ion and lactic acid that is often found in cheddar cheeses – usually on the surface where moisture can accumulate:
As the cheese ages, the culture breaks down the lactose in the cheese and produces lactic acid. As the level of lactic acid in cheese rises, they can begin to bind with calcium ions, forming calcium lactate. As calcium lactate levels rise, they eventually reach a point where they crystallize and become visible to us as crystals.
The crystals are powdery in appearance, and although they usually appear on the outside of the cheese, they can also be found on the inside. Storing cheese in loose packaging or exposing it to temperature fluctuations may encourage the formation of calcium lactate crystals, but in any case there is no reason to be concerned about their presence. Your cheese is still perfectly edible.
What are tyrosine crystals?
Tyrosine is an amino acid, a molecule that links with itself to form the chains that make up proteins. It appears as distinct white speckled lumps when crystallized and is often found in holes in aged cheeses such as Gouda or inside a Parmigiano-Reggiano mug. Crystals that crunch nicely between teeth indicate protein breakdown, according to cheesescience.org :
Unlike calcium lactate, which we attribute to cheese intrinsic factors, tyrosine crystals appear to be associated with culture activity of Lactobacillus helveticus. This microbe is commonly added to the aforementioned cheeses to aid flavor development. L. helveticus has the ability to break down peptides (that is, protein chains) into free amino acids, one of which is tyrosine. As tyrosine accumulates, it eventually crystallizes. Although this is not yet fully understood.
Unlike calcium lactate, the way cheese is processed and stored does not appear to have much effect on the formation of tyrosine crystals. However, the presence of crystals indicates that your cheese is well aged and probably very savory, so if you see tyrosine crystals on your cheese, rejoice my friend.