Mo: What is a good way of keeping a brick of cheese fresh, for example Parmigiano-Reggiano?

Rachael: Parmigiano-Reggiano is already aged a long time. It's very salty and dry, and will keep indefinitely. It will just get saltier and drier. It can even be aged on the countertop. Younger, fresher cheese will mold. It's a natural protection for the cheese as it ages. If the cheese molds, do not throw it away. It's a natural process; it's perfectly edible. At Macy's, I sold 300 cheeses, many of which we paid a premium for so that they would come into our store with mold all over them! If you are using a table cheese or a soft cheese and it has grown a small bit of mold, just trim it with a small sharp knife and uncover the delicious beauty that is waiting underneath.

- From a Food Network online chat event