Pantry staples don’t last forever, but they come relatively close by perishable standards. They last so long, in fact, it’s easy to forget exactly how long they’ve been sitting in the pantry, and, when you need that scoop of katakuri powder for stuffed shiitake mushrooms or a dash of mirin for white miso dip, you might ask yourself, I wonder if this is still good to use? It probably is, but knowing exactly when a pantry staple expires can save you a trip to the market to buy another batch.
An unopened bottle of soy sauce keeps for three years before quality diminishes, while an opened bottle of soy sauce stays fresh for two years, when stored in the refrigerator, before quality diminishes. Opened or unopened, soy sauce stores well at room temperature, but you might get a few more months of quality if you store it in the refrigerator.
Miso paste keeps indefinitely when unopened. Light-colored miso pastes stay fresh for about nine months after opening, while dark miso pastes stay fresh for about a year and a half. Transfer packages or containers of miso to airtight storage containers after opening them and keep them in the refrigerator or freezer for the longest “best-by” duration. When turned, miso develops mold on its surface.
White rice that hasn’t been cooked stays fresh indefinitely. Uncooked brown rice, however, due it its oil content, has a shelf life of three to six months at room temperature, six to 12 months in the refrigerator and 12 to 18 months in the freezer. The ideal storage temperature for uncooked rice lies between 55F and 70F, with optimal humidity of 15 percent.
How you store rice is just as important as its storage conditions — not to prevent spoilage, but to prevent the introduction of contaminants such as dust and insects. After opening a package of rice, store it in an airtight container or sealable food bag. Store packages of brown rice in airtight containers or freezer bags in the refrigerator or freezer. Signs of spoiled brown rice include a rancid odor and oily texture.