Have you ever unwrapped a piece of cheese you just bought and found that the first slice tasted like cardboard? This happens to me pretty often—more than it used to—but at least I know what to do about it. With a little trick that I’m going to share with you, I can usually remedy the problem quickly so the cheese smells and tastes like it’s supposed to.

That cardboardy cheese is oxidized, probably from being cut and wrapped in plastic film days before and exposed to conventional (non-LED) store lights. The lipids in cheese degrade quickly under light, within a few days or even faster. The taste, at least on the surface, becomes stale, sometimes a bit metallic or plasticky.

If you shop at staffed cheese counters (and I hope you do!), you may have seen the monger unwrap a partial wheel, scrape the exposed face with a knife to freshen it and then cut your wedge for you. Alas, this experience was more common pre-Covid; many counters are still not cutting cheese to order. You’re obliged to take a pre-cut piece.

I avoid pre-cuts if I can but it’s not always possible these days. That’s why I’m unwittingly bringing home more oxidized cheese. So I do what a good monger would do: Before tasting it myself or serving it, I lightly scrape any exposed surfaces with a paring knife to remove the outermost layer. You don’t usually have to scrape much to release that fresh, cheesy aroma. Here, using a wedge of Black Label (6- to 9-month) Appenzeller, is my simple hack:

Plastic wrap often leaves a sheen on the cut surfaces. I find that if I scrape until I don’t see any sheen, that’s sufficient to banish the oxidized smell. Sometimes the oxidation goes deeper and I have to scrape more, which makes me cranky because that’s money down the drain. Be sure to check the “packed on” date when you purchase a pre-cut piece.

Vacuum-sealed cheeses are protected from oxidation because there’s little or no oxygen in the package. But most artisan cheeses are not vacuum sealed. Some stores have transitioned to LED lights at the cheese counter to minimize the problem. But in the five years since I interviewed a knowledgeable food scientist about lightstruck cheese, I haven’t noticed improvement.

Of all the negative consequences of Covid, the rise in pre-cut cheese doesn’t make the Top 100. Still, it’s handy to know what to do about an oxidized piece, and you can protect yourself even more by shopping at a store with rapid turnover.