The more water a dairy product contains, the more perishable it is. The more aged and processed the cheese is, the better it keeps. Bacteria need high moisture to thrive and they spoil milk, cream and high-moisture cheeses with pleasure and expediency.
As we already know, milk curdles when we add acidic foods, but it also curdles naturally without your help if you give it time. Lactic acid-forming bacteria build up the acidity slowly if the milk is cold, but they multiply fast, complete the job and curdle the milk within hours at warm room temperatures.
Milk freezes well. If you have too much milk on hand, pour it in plastic containers, self sealing bags or store it in its original carton in the freezer. It keeps well for 2 to 3 months and tastes fresh and remains lump free when defrosted.
Butter is moderately perishable, but it is notorious for picking up odors from other things around it. Never store it in the refrigerator uncovered even for short-term storage.
What actually makes butter spoil is oxidation, caused by exposure to both light and air which turns it rancid.Wrapping it tightly in foil instead of the waxed paper it comes in almost doubles its shelflife. You may have noticed that better-quality butters are often foil-wrapped.
Refrigerated unsalted butter has a shelflife of a few weeks. Butter freezes well and it stays good for several months in the freezer. Salted butter lasts at least three times longer in both the refrigerator and freezer without deterioration. When defrosted, you cannot tell the difference in flavor or texture.
Freezing, on the other hand, separates cream. It breaks down the emulsion, so the fat separates from the water. But if you freeze it very fast, the emulsion stays intact. If you have extra cream that you want to freeze, take a clean baking sheet, chill it thoroughly in the freezer and pour a thin layer of cream on it. Freeze it, then scrape the frozen cream into a plastic container or plastic bag. After defrosting you can even try to use this cream for your coffee.
Whipped cream freezes very well. Put dollops of whipped cream on a sheet of waxed paper laid on a baking sheet and freeze them for an hour. Then collect these individually quickfrozen dollops in a plastic bag to store in the freezer. You can use them as freshly whipped cream after defrosting. Freezing preserves its structure virtually intact.
High-moisture cheeses keep for several weeks, lower-moisture hard cheeses at least twice as long, even several months when you store them properly. The less you touch the cheese, the fewer bacteria you transfer to its surface, and the longer the shelflife.
Handle freshly-opened cheese only with clean hands. Wrapping cheese well to eliminate both microorganisms and oxidation extends its shelflife, too.
When surface molds attack stored cheese, don’t throw the whole piece out. They are not harmful, just disgusting looking and tasting. Scrape or cut off a thin layer, and the cheese beneath it is still perfectly good to eat. But once a piece of cheese is heavily coated with mold, scraping is not enough. The moldy flavor may have permeated the entire chunk.
Dry, low-moisture, well-aged cheeses, such as romano and parmesan are stable even without refrigeration. But if you are planning to store them for several months, you should keep even these cheeses chilled to reduce the rate of oxidation, thus rancidity.
Ripe, well-aged cheeses continue aging even in storage, though slowly at refrigerator temperatures. Storing them too long allows them to overripen, their flavor gets unbalanced and too intense. Often these cheeses, like brie, come in a wrapping something like waxed paper, but if you look closely, there are tiny holes all over the wrapping (called microperforated packaging).
These tiny holes let the cheese breath while ripening. Aging produces excess moisture that you want to release to prevent spoilage. Don’t rewrap these aged cheeses in plastic wrap. Use the original wrapper or kitchen waxed paper.
Don’t freeze cheese if you don’t have to. Freezing doesn’t affect flavor, but you destroy its texture, and it turns mushy after thawing. It is perfectly fine in any cooked dish, since it still blends well with other ingredients.
If you need to freeze excess cheese or just want to have some for cooking in the freezer, grate it first then store in labeled freezer bags. That way you can use small amounts at a time when you need it.