What is the best way to store Parmesan cheese?
To determine the best way to store Parmesan cheese, we consulted several of the sources who helped with research for the tasting article and got three different recommendations for wrapping Parmesan for storage. Before we even got to the question of wrapping, though, there were several points on which everyone agreed. First, it is best to buy small pieces of cheese that will get used up in the course of one or two meals, thus eliminating, or at least reducing, the need for storage. Assuming that there is some cheese left to store, everyone agreed that the relatively humid vegetable crisper was the best spot for it in the refrigerator.
In terms of storage, it was acknowledged that the cheese should be allowed to breathe, but just a little. Full and prolonged exposure to air oxidizes the cheese, which degrades both flavor and texture. So the cheese should be wrapped in a way that limits its breathing. The three specific wrapping recommendations we got from the experts were as follows: (1) wrap the cheese in a slightly moistened paper towel and then in a layer of aluminum foil (a method also recommended for large chunks of 2 to 3 pounds or more); (2) wrap the cheese in parchment paper and then in either plastic wrap or foil; and (3) simply wrap the cheese in parchment, wax paper, or butcher paper alone. To these ideas we added the two methods used most often by home cooks: (1) put the cheese in a zipper-lock bag and squeeze out the air before sealing, and (2) wrap the cheese directly in plastic wrap.
To determine which method works best, we wrapped five 3/4-pound pieces of Parmigiano-Reggiano, all the same size and shape and all cut fresh at the same time from a single wheel, using each of the five methods. We then stored them in the vegetable crisper of our test kitchen refrigerator for six weeks. We monitored flavor and texture by tasting each piece every other day. Differences began to show up at the one-week mark, and all the subsequent tastings remained consistent. At one week, the sample wrapped in paper towel and foil seemed slightly soft and chewy, the parchment-wrapped sample was starting to dry out a little, and some tasters felt they detected a faint "off," sour flavor in the plastic-wrapped sample (a new sheet of wrap was used every time the cheese was rewrapped after tasting). The best flavor and texture belonged to the cheese wrapped in parchment and then foil, though the cheese simply thrown in a zipper-lock bag was almost as good. And so it went. At the four-week mark, the paper towel and foil-wrapped cheese was downright mushy, the parchment-wrapped cheese was so dry we were calling it cheese jerky, and the plastic-wrapped cheese tasted distinctly sour and astringent. The parchment and foil-wrapped sample was still the best of show, followed closely by the zipper-lock bagged cheese. At the six-week mark, both of these samples were still fine.
Our conclusion, then, is to stick with the easiest method. If you must store a small piece of Parmesan, just toss the cheese into a small zipper-lock bag and squeeze out as much air as possible before fastening the seal.