How Long Can You Keep Miso Before It Spoils?

Miso is a flavor bomb of Japanese cuisine, but many cooks don't fully understand how to use it or, even more important, how long you can keep it before it goes bad. The paste, which can be made from a variety of fermented ingredients and a whole lot of salt, can last a long time when stored properly, making it an ideal staple to jazz up all kinds of dishes. Unopened, miso can last up to a year past its expiration date, and even longer if it's refrigerated. Once it's been opened, it usually lasts for up to six months in the fridge before it starts to lose its freshness. Despite the fact that fermentation and a heavy dose of sodium help preserve it, miso can still lose its freshness and even spoil.

The most obvious way to tell your miso has gone bad is the presence of mold. According to the USDA, even just some surface mold is cause for concern because it can invade the food below. Rather than scrape off the mold and hope for the best, it's best to toss out the miso and pick up a fresh batch. As miso begins to spoil, you may also notice a change in color and smell. However, the smell test isn't the most reliable way to make your decision about its freshness because foodborne pathogens don't always have an odor. It will likely start to darken though; throw it out to avoid making yourself and others sick.

While miso can last a long time if stored properly, your best bet is to use it up before you even have to worry about that. With the umami blast it adds to recipes, why wouldn't you want to show off your culinary skills by adding a little bit in the most unexpected dishes? Of course, there are plenty of miso soup and ramen recipes that require a dollop of this high-flavor ingredient, but it can also be used to create a savory marinade for meat and fish, by mixing it with other ingredients like soy sauce and mirin. Creative chefs think outside the box with this ingredient, such as by adding it to comfort foods like peanut butter and jelly sandwiches or to a delicious and mouth-watering tuna salad.

If your miso has started to dry out, all hope is not lost. That doesn't mean it has spoiled, just that it has begun to lose moisture over time. You can still bring it back to life — simply take it out of the package and toss it into a bowl with a small amount of water. Stir it thoroughly until you've achieved the moist texture of fresh miso paste and you are good to go.