Kōji is indistinguishable from magic
René Redzepi ~owner of Noma, voted best restaurant in the world five times, including 2021
Shio kōji chicken is a favourite dish in our house. The kids love it because it is really delicious. We love it because it is so simple and easy. It is one of the quickest Japanese dishes we prepare, if you disregard the couple of weeks of fermenting and the 24 hours of marinading…
Firstly, let’s talk about kōji. Many people are a little freaked out by the concept of kōji being a mould. We actually eat lots of types of mould in cheese and other foods. Everyone has probably had kōji mould before, without realising it. Kōji, or aspergillus oryzae, is used to make soy sauce, miso, sake, mirin and rice vinegar, amongst other things.
Rice inoculated with kōji is called kome kōji. You can buy this rice ready-inoculated and ready to use at a Japanese grocer. With the increasing popularity of fermentation, it is becoming easier to locate.
Shio kōji is made simply using inoculated rice, salt and water, and time. The fermentation time will be dependent on the temperature, anywhere from 1-3 weeks. Shio kōji is a very versatile ingredient. You can use it as a seasoning, marinade, tenderiser or for pickling. The enzymes in the kōji break down the protein in meat to extract umami flavours and making the meat very tender.
Secondly, the recipes. Firstly, shio kōji. Secondly, shio kōji chicken.
Shio kōji
Ingredients:
- 300g kame kōji (kōji inoculted rice)
- 300ml water
- 30g salt
You can use other amounts of kōji and water, depending on the size of your jar and packet. However, the ratio of kōji to water must be even and the ratio of salt is 5% of the combined total of the other ingredients.
Method:
- Pour kōji inoculated rice into a clean glass jar.
- Add the salt.
- Then add the water.
- Stir and cover with a tenagui or muslin cloth and secure.
- Stir twice daily. Top up with additional water to maintain a 1-2cm water barrier on top of the rice.
- The shio kōji is ready when the rice has softened and the mixture has become paste like and the smell changes from a cereal smell to a sweeter smell (not dissimilar to beer). It should taste slightly sweet and salty at the same time. This can take a couple of weeks. It will happen faster in the warm weather.
- Whiz with a handheld mixer into a smooth paste consistency.
- Shio kōji can be stored in the fridge for up to 6 months. This will stop it from fermenting further.
We use this ratio and use half a batch with around 1.2kg chicken for 6 people.








Shio kōji Chicken
Ingredients:
- 1-1.5 kg chicken thigh fillets (approx.)
- Half a jar shio kōji (about 1 cup)
- 2 tbsp soy sauce
- rice and vegetables to serve.
Method:
- Stir shio kōji and add soy sauce.
- Lay chicken fillets flat in a marinade dish. Smother with shio kōji mix.
- Marinade in the fridge overnight.
- Place fillets on a baking paper lined tray and put in a pre-heated oven, 180℃. (Ensure there is not too much shio kōji on the tray, as it will burn. However, you want to make sure there is enough on the chicken).
- Cook for around 25 minutes.
- Serve with Japanese rice and vegetables.
Super Sake Boy is the kōji master in our house and this recipe is so delicious. The chicken literally melts in your mouth. I highly recommend trying this easy, if somewhat time consuming recipe. We try to have a batch on the go most of the time.









If you are interested in exploring kōji further, here is a link to an excellent Epicurious article in which I found the opening quote. https://www.epicurious.com/ingredients/what-is-koji-how-to-use-article. If you would like to understand umami a little better, you could read my blog What does Umami Mean?