Miso is a fermented soybean paste from Japan used as seasoning throughout Asian cuisine. Miso soup may be its most familiar application, but it makes an appearance in everything from salad dressings to pickles and marinades. It’s even one of the crucial components of [soy sauce](https://www.masterclass.com/articles/whats-the-difference-between-soy-sauce-and-tamari). The history of miso can be traced to its ancient Chinese counterpart, soybean *jiang*, one variation in a genre of thick pastes known as *jiang*.\nMiso is the ultimate reference point for the flavor sensation known as umami—the thick paste is deeply savory, with toasty, funky salty-sweet richness. This umami flavor forms the base of a lot of everyday Japanese cooking.\n\nMiso paste is made through a two-step fermentation process. First, a grain—typically rice or barley, but sometimes soybeans—is combined with a mold called *Aspergillus oryzae* to create *koji*. The koji, acting here like enzyme jumper cables, is combined with cooked soybeans, water, and additional salt and allowed to further ferment for up to 18 months, unleashing the effects of yeast and lactic acid. The resulting paste is then ready to use.\nThe different types of miso are defined by tiny but impactful iterations: not only do flavors, aromas, texture, and color vary seasonally and by region, the choices made during fermentation (duration, temperature, vessel) and seasoning (added salt and koji type) have slightly different outcomes. \n\n- __Shiro miso__. Also known as white miso, shiro miso is the most commonly produced type of miso. Made with rice, barley, and soybeans, shiro miso is a softer expression of the form, with a mild, sweet taste. \n- __Kome miso__. “Rice miso” is one of the most widely available, and can be found in different colors (white, yellow, and red) that vary in strength and sweetness, with nuances down to whether the soybeans in the paste have been boiled or steamed. \n- __Aka miso__. “Red miso” is aged for longer than shiro miso, which gives it a deeper hue. As the color shifts to a rusty red (sometimes even black), the saltiness deepens and the flavors increase in intensity. \n- __Awase miso__. Meaning “mixed miso,” awase is exactly what it sounds like: a mix of many different misos, allowing for different permutations of flavor between the types. \n- __Mugi miso__.”Barley miso” is made from barley malt. This light yellow miso tends to carry a deeper sweetness than something like red miso, with a more pronounced malty funk. \n- __Mame miso__ and __Hatcho miso__ are reddish-brown dark misos made entirely of soybeans, with no grains used even in the koji.\nMiso is either dissolved directly into a broth (as seen in miso soup recipes and some kinds of ramen), or used as a spread, dip, or glaze. Use this Japanese ingredient as a marinade with sake and mirin on fish, then finish in the broiler—the nutty flavors in the miso and sugars in the marinade caramelize nicely. Or, add 1 teaspoon miso to your next salad dressing, with a little freshly ground ginger paste, 2 tablespoons sesame oil, and 1 tablespoon rice vinegar.\n\nBecause it’s fermented, miso is a good source of probiotics, but the overall health benefits are debatable mostly due to its high salt content, which places some individuals at risk for increased blood pressure. Miso made with barley koji is not gluten free, but miso made with a rice koji or soybean koji are.\n\nSince miso is already fermented, it’ll keep in the refrigerator for around a year—but check the best by dates just to be sure.\n\nTo make miso soup, add a small spoonful of miso to a warm cup of dashi and stir to dissolve. Top with small cubes of tofu and wispy green onions, and serve with fresh rice.\n\nDemystifying miso, the integral Japanese culinary building block.