What is Miso? Everything You Need to Know

I love making my homemade miso and incorporating it into my diet as much as possible. Discover everything you need to know about this key healthy Japanese ingredient, the diverse ways you can use it in your own cooking, and why you should try making your own.

What is miso?

Miso is one of five core Japanese ingredients, along with soy sauce, mirin, sake, and rice vinegar. All are created using fermented rice, also known as koji. Miso has a long history that can be traced back over 1300 years, and it is thought to have arrived from ancient China to Japan in the seventh century. Miso is incredibly important to Japanese people, with each person consuming around 4kg of miso per year.

Miso is essentially fermented soybean paste, and it requires very few ingredients to create: just koji, sea salt, and soybeans.

Though it's a very simple recipe, and easy to make at home, the results can be very varied since there are different many different types of koji you can use, including rice, bean, wheat, and barley koji. It’s not suitable for people with soy allergies but Clearspring has made a miso from chickpeas which could be a great solution.

The fermentation time of the miso can also make a big difference to the flavour. I love to ferment my miso for twelve months to really develop the umami flavour. I used to make big batches but now I prefer to make smaller batches more often so I can have different flavours of miso throughout the year.

Of course, no two batches will ever taste exactly the same as small differences like the type of salt and temperature it's kept in can make the flavour completely different. When you start to make miso regularly, it quickly becomes a hobby like winemaking, you will catch yourself saying ‘...was a good year’!

Natto is also believed to lower blood pressure and reduce cholesterol. For this reason, many people eat it, even if they don’t enjoy it. Thankfully, my daughter and husband love it so I always have a well-stocked freezer full of natto.

Being a fermented food, it is also full of probiotics and very healthy for your gut. As you know, I love to incorporate fermented food into my diet as much as possible with simple additions like this lemon koji seasoning, or even homemade miso. So natto is a regular staple in our house.

Miso has many health benefits

Like other fermented foods, such as koji and kimchi, miso is very good for your digestion as it promotes healthy gut bacteria known as probiotics. This has an overall positive effect on the body including boosting the immune system and supporting cognitive health. It’s also high in both vitamins K and B12 which both promote healthy blood flow.

Many people are concerned about the level of sodium in their diet but, because miso is fermented, it’s easier for your body to process the sodium content — in fact, sometimes Japanese people will have miso two or three times a day.

If you are worried about sodium content then make sure to buy high-quality miso or make it yourself as the longer the fermentation period the less miso you will need. Commercial miso will have higher levels of sodium due to the comparatively short fermentation time.

What are the different types of miso?

With thousands of master miso makers across Japan, miso forms a rich culture and can be thought of like beer in that each region of Japan has a slightly different flavour, strength, colour, and taste of miso.

As a general rule, the darker the miso, the longer it has been fermenting and the stronger the taste will be. For example, Nagoya area is famous for the very dark Hatcho miso, which is fermented using large seasoned cedarwood kegs and left to fully mature for up to three years.

Kyoto miso, however, is considered a speciality miso and is a less mature miso — it’s made with rice and more koji which results in a less salty, sweet and light flavour. In fact, historically, wealthy landowners, royalty, and samurai preferred this type of light rice miso and poorer people would have to make their miso from other grains such as barley. Today barley miso is also very popular, its high percentage of barley used during the fermentation process results in a thick, wholesome taste.

My miso is rice koji based so it’s an everyday miso which is perfect for soups, and marinades — this medium style of miso is very popular in the Tokyo and Kanto regions, where I am from. As I leave my miso to ferment for a year, it is highly fermented so you need to use less whereas most commercial miso has a short fermentation time so it’s very salty and has less umami flavour.

How to use miso in your cooking?

When people think of miso, they often immediately think of miso soup! While miso soup is both nutritious and delicious, it’s really just scratching the surface of how you can incorporate miso into your everyday cooking.

When approaching cooking with miso, it’s best to use some common sense but it’s also fun to experiment with! Generally speaking, it’s best to stick to light miso for more delicate dishes as not to overpower the other flavours and darker miso when you want a deep umami flavour. Having two or three types of miso in the fridge is ideal.

Some of my favourite recipes using miso include these baked miso chicken squares which are ideal as party canapes or this perfect week-night quick umami-rich baked miso chicken curry.

Miso is also an ideal addition to soups and salads as it adds depth of flavour and a salty taste. I like to use it in these healthy kabocha pumpkin soup recipes where you can experiment with two different types of miso as well.

It also makes a great base within salads, as part of a salad dressing or in this shirra-ae tofu recipe which combines the delicate flavour of white miso with tahini and silken tofu.

There is also a famous miso dish that you can find internationally, that can be expensive but is worth trying at least once if you eat fish due to the perfectly married flavours — black cod with miso!

It actually originated in Beverly Hills in the 1980s by Japanese chef Nobu Matsuhisa and quickly took the dining scene in the US by storm. The technique involves marinating the creamy black cod for three days in mirin, sake, white Kyoto miso, and sugar and is then served grilled.

Where to buy miso?

You can buy commercial miso in most supermarkets and Asian supermarkets at varying degrees of quality. But for high-quality miso, which has a more mature flavour and enhanced health benefits I highly recommend ordering from:

Clearspring who have a number of miso options including barley, hatcho, and also their chickpea miso which is perfect for those with soy allergies (use code yukiskitchen15 for 15% off your total order).

The Wasabi Company who have a wide selection of miso including their popular twice fermented miso made by master craftsmen in Kyoto. They also have a wide range of miso starter kits, and even vegan miso mayonnaise (use code YUKI10 for 10% off your order).

Once you have opened your miso, whether it’s homemade or from a store, you must keep it in the fridge but you can ignore the expiry date.

Why make homemade miso?

So why make your own miso when you can buy it? There are so many reasons why making miso at home is a great idea apart from being a fun hobby.

Homemade miso is full of amino acids and is better for your health overall because of the longer fermentation time. It’s simple to make and very satisfying.

I recently taught a miso workshop in Pantechnion, a new Japanese lifestyle space where you can enjoy everything from Japanese food to lifestyle, I’m very excited to share fermentation and miso with people.

That’s why I’m also teaching a London Miso and Umamai Koji Workshop where you can learn to make miso using my family’s recipe from my home region in Japan and discover the benefits and flavours of fermented ingredients. You will also take miso home with you and learn how to apply your miso to different recipes.