The white spots on Parmigiano Reggiano – mold?


Parmigiano Reggiano 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 Parmigiano umami savory taste. The longer the maturation, the stronger the taste, and therefore higher in price.

I discussed deeper about the kind of bacteria here in this article.

While the maturation of the cheese can take up to years to happen, it’s normal to see white spots or specks appeared on the Parmigiano Reggiano. Like many other hard kinds of cheese (including asiago and gouda), the white spots also called “pearls” resemble the crystallization of amino acid protein, which in particular, tyrosine and leucine (1).

This is especially noticeable on more than 2-years old of Parmigiano Reggiano. Due to the rind skin are brushed and dried in brine, which acted as a coat for the inside, most crystals can be seen on the rindless side of the Parmigiano cheese, but less on the exterior rind.

That goes for the kind of sliced Parmigiano you bought at the store, such as this one I found on Amazon. Judging the review section, most people are quite liking that cheese.

These are the legit white crystals formed by amino acid crystallisation.

The normal white spots like in the image above are generally safe to be consumed. If you don’t find it appetizing, or ideal for the children, elderly, or people with the weakened immune system, you can always scrape it off, or cut off at least 1 inch below the moldy spot.

You can’t do the same in soft cheese like Gorgonzola, learn why here.

Just like yogurt, the lactic acid bacteria involved in cheese ripening catabolize the lactose into lactic acid (2), therefore most cheese are low in lactose content.

Inside the cheese is a huge ecosystem for microorganism. Each of them works together — is the secret behind of producing good cheese.

White mold – Should I throw them away?

In some cases, the white spots that grew on Parmigiano Reggiano are not the actual amino acid crystals, but a combination of different bacteria and fungi, such as the E. coli, Scopulariopsis, and Salmonella. See featured image above. It happened when you didn’t store or handling the cheese well, or kept in the wet environment, it can grow mold pretty quickly.

By the way, people often say cheese smells like feet, here is why.

As cheese is the natural breeding ground for the selected bacteria to grow, which gives the cheese a desirable aroma and texture, it’s not unusual to see the bad ones come along. In ideal circumstances, the high number of good bacteria will produce anti-microbial compounds to resist the growth of bad bacteria and mold, and therefore safe for us to consume.

Speaking of mold, the patterns are not the usual looking of plain white spots, but instead, the mold may look like patches of black stain, fuzzy white, or just like bread mold. Depends on the types that grew on it, it can be in various colors, including black, blue, green, yellow and grey.

If you proceed to eat the cheese with mold, depending on the type of germs (some produce toxins), you can get very sick from that. To prevent that, it’s better to discard the whole piece of cheese than taking the risk of eating them.

Wrap up

In the making of Parmigiano Reggiano in Italy, no additives were added to better preserve the cheese for storage. So, it’s normal to see the growth of mold if didn’t store well, as it also implies that the pieces of cheese that you bought could be the true Italiano Parmigiano.

Wait a sec, you may not know the differences between Parmigiano Reggiano vs Cheddar, spend a min there.

AaronMH

I have a background in biotechnology, and I love cats.

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