Natto starter culture | make your own nattō (including recipe)

Make your own Nattõ with this natto starter!

What is nattō

Nattō (or simply natto) is a Japanese food made of fermented soybeans. For the preparation we use the bacterium Bacillus subtilis var. natto. The change from soya beans to natto goes via alkaline fermentation, whereby proteins (not carbohydrates) are converted into amino acids, peptides, and ammonia. This form of fermentation increases the pH. This makes the food not acidic, but alkaline.

What does natto taste like?

Traditional natto has a pungent, savory umami flavor with nutty, earthy notes that resembles aged cheese. Its mouthfeel in particular is distinct. Natto beans have a slippery texture, with a soft, but still slightly crunchy interior. It’s generally considered an ‘acquired taste’. Much like similary strong tasting products like blue cheese, it takes some time to get used to, but then you’ll be hooked forever!  Natto can also be made from other beans than soy beans such as mung beans or chick peas or even grains which allows for a wide variety in natto flavors.

How do you eat natto?

Usually, natto is not consumed on it’s own, but combined. A classic combination is with rice, soy sauce and spring onion. But, natto can be added to soups, or eaten with eggs or vegetables. It’s a versatile food product, adding umami and proteins to many dishes.

Why is natto so stringy?

Those strings are natto’s signature and they do not come from the soybean but from the bacterium. During fermentation Bacillus subtilis secretes polyglutamic acid, a long chain of glutamate molecules strung together. The chains form a slime layer around the beans, and when you pull them apart they stretch rather than snap. The longer and warmer you ferment, the more polyglutamic acid and the longer the strings. Want them shorter, ferment less. Stirring before you eat makes them more pronounced, which is exactly what they do in Japan.

How much protein is in natto?

Natto made from soybeans sits at around 18 grams of protein per 100 grams. Use chickpeas, mung beans or barley and that number drops, and so does the texture: barley strings far less than soy.

Other names for natto

Outside Japan variants of natto are made in Thailand (thua nao), China (dau chi), Nepal and Burma (kinema), and Korea (chungkuk-jang).

Natto can also be made with beans or grains other than soybeans, such as barley.

Buy our natto starter

• Available in two sizes: for ca 500 grams of natto or for 5 kg (70% discount).
• Ingredients: maltodextrine, Bacillus subtilis bacterium, L. plantarum 
• Origin: China
• Allergens: not yet declared by the producer for this grade.

Tip: weigh this with a precision scale that measures in increments of 0.01 gram, because you measure it out in tenths of a gram.

Shelf-life and storage of your natto starter

• The date printed on packaging is the date of manufacture, not the best before date. The shelf life is the printed date + 24 months.
• Storage instructions: keep in the fridge for at least 6 months, up to 2 years in the freezer

How to make your own natto with our natto starter

Natto is not hard to make. This recipe is for 250 grams of dry soy beans (enough to feed 4), but you can make less if you want to. After soaking and cooking this will give you around 500 grams of natto. Buy your natto starter and let’s go!

Tools

• Oven, or food dehydrator

Ingredients

• 250 grams of dry soybeans
• 1 bag natto starter dissolved in a small amount of (preferably distilled) water.

Preparation

1. Buy your natto starter
2. Wash the beans and soak them overnight in plenty of water.
3. Cook the soft beans for about four hours.
4. The beans do not need to be dehulled.
5. Mix the natto starter culture with the still hot (!) beans.
6. Allow to cool to about 40 ° C.
7. Ferment covered with plastic wrap with some holes pricked in a lukewarm oven at about 40 ° C (38-45) for 24-36 hours. Note: not higher than 45 ° C.
8. Test the natto: a kind of slimy strings  should have developed between the beans.
9. Let mature in the refrigerator for around 24 hours before eating.
10. Enjoy

Tip: try natto from other beans too, such as chickpeas. Different bean, different natto, and to my taste a better one.

How to store natto

Pack portions in bags or trays and freeze them. This way, natto has a very long shelf life.

How to make natto taste even better

The strong flavor means a little natto goes a long way, so it’s usually consumed in small portions mixed with plainer ingredients like rice to balance the intense taste and texture. You can adjust the balance to your liking. If you’re into sushi, this is a perfect way to incorporate natto into your food. Natto maki  for example is a sushiroll variation  where natto is used as a filling, sometimes combined with other ingredients like cucumber, shiso leaves, or egg. And of course, when in doubt: more soy sauce!

Buying a natto starter?

Order your natto starter at startercultures.eu, the European webshop for all your fermentation needs. By Meneer Wateetons, renowned Dutch fermentation expert and teacher and author of 9 cookbooks. He has taught thousands of hobbyist and chefs on the art of fermentation, including making natto.

Order on weekdays before 3 pm and we’ll ship the same day. Questions on the usage of the natto starter? Ask them in our chat, we’re here to help!

FAQ

Is natto hahal?

Natto is soybeans and the bacteria you ferment them with. So yes, it is halal.

Is natto vegan?

Soybeans and bacteria, no animal ingredients. So yes, it is vegan

What does natto taste like?

Strongly savoury and umami, with nutty, earthy notes closer to aged cheese. And then there is the smell, which no sentence quite covers. An acquired taste, like blue cheese.

What can you combine natto with?

Here are some suggestions to ‘tame’ the flavor of natto

• Over hot white rice with finely chopped green onions, a dash of soy sauce, and karashi mustard – the rice provides a neutral base while the green onions add freshness
• Mixed into miso soup – the miso’s familiar umami helps bridge the gap
• In onigiri (rice balls) – the rice wrapping makes the texture less prominent
• Also: drying it will keep all of the goodies, but none of the texture.

Making natto safely

• Boil or steam the soybeans until done and let them cool to inoculation temperature before you add the starter.
• Ferment at the stated temperature and time. Refrigerate the natto right away afterwards.
• Keep natto refrigerated and eat it within the stated period.
• Start every batch with fresh starter.

Online Natto making course

Natto is a traditional Japanese dish made from fermented soybeans. It is known for its texture, its smell and the fact that it divides a room. In this online course, Meneer Wateetons teaches you how to make your own natto from now on, just in your own kitchen, and how to make whole new kinds of natto from beans other than soy, which are therefore tastier, prettier and more original than those from the store.