The white spots on Parmesan – mold?

Parmigiano Reggiano (aka parmesan) is known for its long aging process which may take up to 3 years to age.

The minimum duration of which can be sold at the store is to have at least one year of maturation. That’s for the probiotic bacteria and enzymatic reaction to kick-in in order to produce the unique Parmesan umami/savory taste.

The longer the maturation, the stronger the taste, and therefore higher in price.

I discussed in detail about the bacteria responsible for that in this article here.

While the maturation of the cheese can take up to years to happen, it’s normal to see white spots appeared on the parmesan. Like many other hard cheeses (including asiago and gouda), the white spots also called “pearls” are the crystallization of amino acid protein (1), which in particular, tyrosine and leucine. They could also be calcium lactate crystals (2).

One good way to tell crystals from the mold is that mold is only on the outside, while crystals will also be in the inside of the cheese.

Crystals is a sign of well aged cheese.

This is especially noticeable for the older parmesan above 2 years, such as this one I found on Amazon.

These are the real parmesan with white crystals formation, jackpot!

The parmesan with white crystals are safe to consume.

If you don’t find it appetizing or not sure whether it’s a mold, you can always scrape it off, or cut off at least 1 inch below the spot.

The lactic acid bacteria involved in cheese ripening breakdown the lactose into lactic acid. Lactic acid binds with calcium to form calcium lactate.

The lactic acid bacteria plays a predominant role in the bacterial composition in parmesan.

White mold – Should I throw them away?

In some cases, the white spots maybe not crystals but mold. It could be a combination of bacteria and fungi, such as the E. coli, Scopulariopsis, and Salmonella.

See featured image above.

It happens when the cheese get contaminated or left out at the room temperature. The mold slowly takes over the cheese in a few days, or even hours.

Cheese is a perishable food. It serves as a natural breeding ground for the certain group of bacteria to live. The bacteria then produces desirable aromas, flavor and texture. However, it’s not unusual to have the bad ones joining.

We control the bacteria, maybe?

Throughout the production process, the bacteria population gone up and down. Some bacteria found higher volume in the early curdling stage, while the other in the later aging stage.

By using salt or brined water, the predominant thermophilic lactobacillus bacteria thrived in a specific environment. They synthesized anti-microbial compounds to resist the growth of others, aka the unwelcoming bacteria strains.

Mold can have many forms or patterns. Some may look like patches of black stains, or fuzzy white things, or just like bread molds. It can be in various colors too.

Is parmesan an organic product? see the answer here.

If you accidentally eat the mold infected cheese, depends on the types (some produce toxins), you can get very sick from that. Do not eat it if you are not sure.

There you have it, the white spots are likely to be crystals most of the time.

Thanks for reading!