What is koji rice? What does it do?

December 10, 2018

Shio koji is becoming popular in England but do you know what it is? Koji is actually in most of Japanese food, such as miso, soy sauce, mirin, and sake. 

What is koji?

Koji is a rice with koii mould. Don't worry, it is an edible mould like the one that is used for cheese. Koji mould is not the kind of mould that spoils food. Koji cant be found in most countries. Koji is a mould of Japan. It likes the Japanese climate. (Humid). Koji lives in rice plants, soy beans and barley.

What does it do?

When koji is applied to ingredients, it produce digestive enzymes which creates umami and sweetness. While it is producing the digestive enzyme, it makes meats and fish more tender too, so even tough steak can be tender by marinating in shio koji. It's made of just a few simple ingredients, salt, water and rice koji. As it's all natural, you get the same umami taste as you would while using MSG but without the additives.

What does shio koji it taste like?

Now all of you must be wondering what it tastes like on its own. It taste like a salt paste that resembles dashi and mirin. If koji is fermented on rice then it is called 'Kome-koji' (rice koji), if it is fermented on barley, then it is called 'mugi-koji'.

Nama-shio koji is a paste type shio koji. 

You can literately add this to anything, you can of course marinate meats and fish with it, you can even cook it in rice. You can eat this raw as well.


Dried koji have a long shelf life and you can keep it for up to a year, but you need to add water to adjust. Also with dried kome-koji, you can home brew shio-koji, miso or amazake.

Shoyu-koji is, soy sauce added to rice-koji, you can marinate meat and fish, it can give shita-aji (secret flavour) , umami and soy flavour to food. 

We have soy sauce that has koji in it, you can just use it as how you use soy sauce, it is thicker than normal soy sauce.

Try this Amazake sauce on sashimi


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