Koji (pronounced “Koh-jee”) “is a kind of bacteria mould, used in a similar way to yeast as a fermentation starter. It is made by adding the koji bacteria to rice, barley or soy beans. It is the base of nearly all the Japanese fermented flavourings and alcohol: sake, miso, vinegar, pickles, soy sauce, shochu, awamori – koji is the star player of them all!
Near my house there is an old koji shop, which is unusual even in Japan. Whenever I go to buy koji, the woman at the shop always gives me great ideas. One of them was shio koji – salted koji. Then a few years ago shio koji suddenly appeared in the shops in Japan, and now you can buy it anywhere. I found it in health food shops in the UK, too. But you can make it yourself very easily. You can buy koji online in the UK. Shio koji is a magic ingredient, great with meat, fish and vegetables.
How to make shio koji.
- 300g rice koji
- 250cc water that has been brought to the boil, and cooled (250-300cc for dried koji)
- 60g salt
1. Put the koji in a bowl and break up the lumps with your fingers, then mix in the salt and mix well.
2. Add the water and mix more.
3. Put the mix into a tupperware or similar, cover lightly with a lid so the air can get to it (don’t seal) and place it somewhere room temperature.
4. Mix well with a spoon once a day.
5. After a week or 10 days the koji will have become wet and sticky, and is ready to use.
6. Keep in the fridge, and use within about 6 months.
Soy Sauce Koji
If shio koji is easy, you can make soy sauce koji in your sleep. But boy is it delicious! Try it, and you’ll see!
How to make soy sauce koji
1. Mix the same amounts of rice koji and soy sauce in a tupperware or similar. Cover lightly with a lid, so the air can get to it (don’t seal) and leave somewhere at room temperature.
2. Mix well with a spoon once a day.
3. After a week or 10 days the koji will have become wet and sticky, and is ready to use.
4. Keep in the fridge, and use within about 6 months.