Everything you need to know about miso

Miso made its way from its original home China to Japan around 1,300 years ago, brought by Buddhist priests. Originally grains, salt and soybeans, like many food items at that time, were fermented to preserve during summertime, which led to miso—an ingredient now synonymous with Japan. Only the rich originally ate miso because it was created with rice, an expensive food back then, though the samurai heard about the energy-fuelling properties and incorporated it into their diet.  

Depending on which miso you ate showed which class you belonged to; the rice miso, as it used polished rice, was consumed by the wealthy while the poorer people would eat the miso made from broken rice, or grains including millet and barley which was darker in colour. Miso was popular far and wide by the mid-14th century and was even an alternative currency in hard times. Today there are over 1,000 producers of miso in Japan. 

Essentially miso contains fermented soyabean paste with rice, or sometimes barley and salt. A koji or “starter” which is a type of fungus called Aspergillus oryzae is used to start the fermentation process. The koji itself is made by introducing the Aspergillus oryzae onto a grain which is most commonly steamed white rice.

Koji is used to start the fermentation process

The strain of Aspergillus oryzae plus its enzymatic composition differs and dictates the various characteristics of the resulting miso. The koji is combined with the soybeans, salt and water that are enzymatically digested, fermented and then aged, which creates the miso.  

Miso contains a variety of beneficial vitamins and minerals including vitamin K, manganese, zinc, protein and calcium which are known to support vital structures such as bones, the nervous system, as well as neurological and psychological functions aiding the reduction of fatigue.

The fermentation process of miso creates healthy bacteria and enzymes (in other words, probiotics) which are renowned to support good gut health, the immune system and digestion. The fact it is fermented means it is said to be healthier to eat miso than plain soybeans because the fermentation lessens the levels of phytates present in the beans. Phytates are antinutrients that can interfere with normal nutrient absorption.  

Antioxidant-rich miso is also believed to reduce the risk of some cancers, like breast cancer, due to the isoflavone content. Miso is also a good source of plant protein and low in calories when mixed with water to make a simple soup. While boasting a bounty of benefits there are a few things to watch out for. For example, if you have a low sodium diet, you shouldn’t indulge in miso, which is salty. If you have a soy protein allergy you’d need to steer clear, and if you take blood thinning medication, vitamin K-rich foods like miso should be limited.  

One of the best ways to eat miso is served simply as a clear soup—just add hot water and sip for an unbeatable umami sensation. You can also spruce it up with the addition of noodles, seaweed, tofu, spring onions and anything else that takes your fancy, including prawns and meat.  

Miso can be enjoyed as a clear soup, spruced up with noodles, tofu or anything else you feel like

To make aubergine even more irresistible, simply cut one in half, score the white flesh with a knife, drizzle with oil and spread over some miso paste, bake in the oven until tender and bubbling and serve. You can use a spoonful of tasty miso to add a rich layer of flavour to most broths, soups, stews and noodle dishes. Ramen works very well.

Jazz up a steak or piece of fish with some miso butter, just blend butter with miso. You could add additional ingredients like herbs too. You can add some miso to your favourite marinades and even salad dressings.

There are various varieties of miso from colour to strength which depend on the koji species used, the ratio to soybeans, type of soybean, whether they are steamed or boiled, the fermentation length, amount of salt and type of grains involved. For instance, if the soybean to koji ratio leans towards soybeans then the resulting miso will likely have a stronger umami flavour. If the koji level is higher you’ll have a softer, sweeter falvour.  

There is white miso, which can also have a beige hue. This has a gentler flavour due to being made with a larger percentage of rice and having a shorter fermentation period. Red miso is fermented for longer and has a higher proportion of soybeans. Awase miso is a blend of both red and white and is used the most, having a balanced, medium strength flavour. It is best to buy miso which needs to be stored in the fridge, meaning it is live, unpasteurised and full of enzymes. 

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