What is Miso Paste
Miso paste is a fermented soybean paste that's a pantry staple of Japanese cuisine. It's typically made from soybeans, koji, and salt. Koji or Aspergillus Oryzae is a filamentous fungus propagated on grains such as rice or barley and is the microorganism that breaks down protein in the soybeans into amino acids which create the taste of umami. Varying the ratio of these three ingredients and the length of time the miso is fermented can result in vastly different flavors of miso. This explains why miso is so region-specific, with hundreds if not thousands of different types of miso.
Types of Miso
Most miso can be categorized into one of three categories based on its color, which is determined by the length of time it's fermented. Shorter fermentation times result in lighter color miso, while longer fermentation time creates darker ones.
White Miso (白味噌 - Shiromiso)
While the color is more light blond than white, Shiromiso is the lightest of the varieties, thanks to its very short fermentation time (as little as 2-3 days). It's made with two to three times more rice koji than other miso paste, giving it a mild flavor and natural sweetness thanks to the enzymes in koji, which convert starches into sugar during the early stages of the fermentation process. It also features a much smoother consistency that's much softer than other varieties that have been aged for longer. The refined texture and flavor of white miso make it a popular choice in Kyoto, known for its elegant cuisine.
White miso also contains less than half the amount of salt compared to other varieties, which means you'll need to use double the amount of paste to achieve the same salinity. This makes it great for use in sauces to maximize the miso flavor without overdoing the salt.
Saikyo Miso is the most renowned brand of Shiromiso, which is why it's sometimes labeled as such. I've found many products labeled "white miso" in the US, but they actually belong in the next category. For this reason, the best way to identify Shiromiso is by its appearance. It typically comes in clear pouches or small tubs, is smooth in texture, and is pastel yellow.
Yellow Miso (淡色味噌 - Tanshokumiso)
While Tanshokumiso directly translates to "light-colored miso," this moniker has led to its unfortunate mislabeling as "white miso" in English-speaking countries. "Yellow miso" is a better translation.
The vast majority of miso falls into this category, and this variety can range in color from peanut butter tan to medium brown, courtesy of its extended fermentation time of six to ten months. This longer aging imparts a more complex flavor than Shiromiso, and with a salt content of between ten and twelve percent, it's significantly more salty.
Yellow miso can also be made using rice koji or barley koji, which further influences its flavor profile. Barley koji tends to steer the miso made with it towards a more robust, nutty profile. Conversely, rice koji-based products tend to be mellower with a slightly sweet taste.
Red Miso (赤味噌 - Akamiso)
Red miso, or Akamiso, is the final category and encompasses all the darker shades. Its bold hue is an outcome of an extended aging process that can last as long as two years. This lengthy duration allows Maillard browning to develop miso paste into shades ranging from dark brown to nearly black. Beyond color, this browning imparts a remarkable depth of flavor, delivering a symphony of nutty complexity teeming with umami. Aided by evaporation, the extended aging also affects the texture, rendering Akamiso firmer and saltier than its paler siblings.
Red miso is not constrained to a single region of Japan; however, its most common association is with the cuisine of Nagoya, and Hatchō Miso (八丁味噌) is their most recognized brand. It's made by steaming the soybeans before crushing and inoculating them with koji spores and barley flour. The koji is allowed to propagate for two days before salt is added, and the beans are transferred to tall cedar barrels topped with a three-ton pyramid of river rocks where the mash is aged for at least two years. This extended process results in a firm paste with a rich earthy flavor that packs loads of umami. This is also known as Mamé Miso (豆味噌), which means "bean miso" due to its low grain content.
Miso should contain only soybeans, koji, grains (rice or barley), and salt. There are many miso-flavored seasonings, but these are typically meant to be used as sauces and condiments and should not be used as an ingredient in recipes that call for miso.
There is also a product called dashi miso, which includes ingredients such as bonito extract and kelp. Because these contain a mixture of ingredients for dashi stock, you can make soup with this product by adding boiling water. Although convenient, I'm not a huge fan as it's the Japanese equivalent of using bouillon cubes to make chicken stock. It also limits how you can use it because you don't want the flavor of dashi in every dish you make with it.
How to Use Miso
Although it's best known as an ingredient in soup, miso is a culinary multitasker that can be used beyond Japanese cooking to elevate many dishes in your repertoire. Use it in place of soy sauce, or add it to your favorite meat sauce to amp up the umami, or use it in bread to give your dough a rich earthy flavor.
Miso makes for the perfect umami-rich seasoning for stir-fries, but because it's a paste, I recommend thinning it out with something else. For example, you can mix it with maple syrup to make Maple Miso Chicken or blend it with butter for Miso Butter Salmon.
Miso paste also makes for a fantastic glaze, marinade, and condiment. If you have Hatcho Miso, try making my Dengaku Sauce as a glaze for eggplant or tofu. When Dengaku Sauce is mixed with sauteed ground meat, it becomes Nikumiso, which can be used to dip veggie sticks in. For salad dressings, my Ginger Miso Dressing is a refreshing way to make a bowl of greens pop.
Of course, no miso round-up would be complete without mentioning the soups you can make with it. The most famous, of course, is Miso Soup, and I have three different recipes utilizing each type of miso. Tonjiru is a cold weather stew which features pork and loads of vegetables in a hearty broth. In the hotter months, Hiyajiru is a refreshing chilled soup made with cucumbers and sesame seeds. In Hokkaido it's even used to season ramen broth and the soup can be used with other noodles as well.
It depends on the product, so check the ingredient label. Miso made with rice koji (米味噌 - kome miso) is typically gluten-free, but it can also be made with barley koji (麦味噌 - mugi miso) or barley flour, which is not gluten-free.
Miso can have a wide spectrum of flavors, and it depends on the type you have. Broadly speaking, it has a savory flavor that's nutty and salty with loads of umami. Lighter color miso tends to be milder and sweet, while darker ones are earthier and more intense.
The expiration date for miso is based on the time it takes to age to a point where the flavor has changed significantly. This doesn't necessarily mean it's gone bad, but if you bought a tub of yellow miso a year ago and it's now dark brown, you have a different product than what the manufacturer intended, which is why the expiration dates are set relatively short. As long as it hasn't been opened (or it's been stored in the refrigerator after being opened), it should still be okay to eat but check for obvious signs that it's gone bad such as mold or an unpleasant smell.
Miso can often be found in the ethnic aisle of supermarkets, but you'll be able to find a wider variety by visiting a Japanese grocery store. If you live in a rural area, try looking for it on Amazon.