What is Shio-koji? How to make and How to use?

Introduction of Shio-koji, Japanese Fermented Ingredient

Mai(はな)
Nov 7, 2019 · 6 min read
Photo by hana, 2019

What is Shio Koji (塩こうじ/塩麹/塩糀)?

Shio Koji (塩こうじ/塩麹/塩糀) is a Japanese fermented ingredient. It’s made of salt, water and Rice Koji (米こうじ/米糀/米麹). We can use it to marinate or tenderize. In Japan, we have lots of fermented food such as Soy sauce or Soybean paste and Shio Koji is one of the most popular seasonings nowadays.

What is Rice Koji (米こうじ/米糀/米麹)?

Rice Koji (米こうじ/米糀/米麹) is steamed rice that has been treated with Koji mould. Koji is an important part of Japan’s food that has been cultured over the centuries.

How to make Shio Koji

Ingredients for making Shio Koji

Dried Rice Koji is easy to handle. There are two types: block and broken down in pieces. Rice Koji is also used for making bean paste, Amazake, and so on.

How to make Shio Koji

Photo by hana, 2019
  1. Note: don’t seal the rid because it produces gas in the process of fermentation.
  2. Stir it every two days and make sure the surface is always covered with the water to avoid it getting dry.
  3. After the grains melt and become soft and it’s fermented enough, keep it in a sealed container in the fridge.

Fermentation and temperature

The process of fermentation depends on the temperature. It ferments slowly at a low temperature and it’s accelerated with a warmer temperature. Please note that the enzyme included in Koji stops working at 60℃. Therefore when you use it for cooking, it is better to cook after marinating to enjoy the taste of Shio Koji.

It also depends on the quality of Rice Koji

This is my second time for making Shio Koji and I used Rice Koji form a different brand. I think the Rice Koji which I used this time was a little newer than the one last time. I realised that the fermentation proceeds faster than the previous time. It was very lively when I put them together in a jar on the first day generating bubbles.

How to use Shio Koji

We can use Shio Koji to marinate meat, fish, to make pickled vegetables and dressing. It can be used just as a salt substitute. It is recommended to use twice as much as using salt alone. For pickling, about 10% of the weight of the pickled ingredients is appropriate.

Pickled Vegetables

Apply Shio Koji to cut vegetables such as cucumber, Daikon radish, eggplants or cabbage, and rub them. Leave it in a cool place for hours and serve it.

Marinate meat (chicken, pork)

  1. Apply Shio Koji to chicken or pork.
  2. Leave it in the fridge: 30 minutes for chicken or a couple of hours for pork.
  3. Bake it on the grill or sautee it in a frying pan.

Marinate fish (cod, salmon, mackerel, etc)

  1. Apply Shio Koji to fish fillet.
  2. Leave it in the fridge for a couple of hours or a day.
  3. Roughly remove the Shio Koji on the fish, and bake it on the grill or sautee it in a frying pan.

Effect of Shio Koji

Make the food delicious

Enzymes in Koji can break down starch and proteins into sugars and amino acids to enhance sweetness and umami. Also because of the effects of lactic acid bacteria and yeast, the ultimate food will have a lot of taste elements, so that you can enjoy the complex tastes more than when you eat ingredients alone.

Make the ingredients tender

Since the enzyme can break down starch and proteins, it can soften the meat when you marinate.

Rich in nutrition

Shio Koji contains more nutrients than salt such as vitamins (B1, B2, B6, pantothenic acid, biotin (vitamin H)), etc, because of the action of enzyme and microorganisms such as lactic acid bacteria and yeast.

Improvement and anti-ageing

The lactic acid bacteria are known for their “intestinal action”, which regulates the intestinal environment. It is said that there is a good effect for improving the constitution or skin condition. You may notice that the skin of your hand and fingers become smoother after you treat the food with Shio Koji.


Japanese writer

A view from Japanese writer, about Japan, to decode its society and to glimpse the culture.

Mai(はな)

Written by

Used to be named as Hana. A Japanese born blogger and writer who currently lives in Canada. https://japanesque-cafe.com/

Japanese writer

A view from Japanese writer, about Japan, to decode its society and to glimpse the culture.

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