Shio Koji / by Megan Tomino

Shio koji is a seasoning agent that is rich in an enzyme called proteases that breaks down protein to produce glutamate, an amino acid that gives us umami. Shio "salt" Koji "malt-rice" contains kokkin - a type of fungus used to make sake, miso, natto, shoyu, mirin, amazake, and more.

My grandma and I took a shio koji making class at the MOA Wellness Center back in April. This class was taught by the masters of healthy Japanese cooking - Mai and Itsuko. I am literally regurgitating everything I learned in this class - so all credit for what I've learned can go to them. I just have to share with my small band of readers just how great shio koji is!

Let's start with breaking down koji. Koji, from what I understand, is rice that has been cooked then exposed to a specific strain of fungus and allowed to ferment. This fermented rice is then "dried" to a certain extent, packaged and sold to other producers to make other products like sake, shoyu, and mirin. As far as I'm concerned, sake, shoyu and mirin are the holy trinity of Japanese cooking - used in more Japanese dishes than I can count. Now, think of being able to use the ingredient all three liquids have in common to season your dish! The result is food that is packed with flavor with a fraction of the salt content.

Shio as many of you might know, translates to salt. When making this concoction we are literally mixing salt with fermented rice and allowing it to ferment event further, thus adding a salty flavor - but because shio koji is so flavorful, you end up using a portion of what you'd normally use when seasoning with regular salt. 1 tablespoon of shio koji = 1/5 teaspoon of salt, without compromising flavor - in fact, shio koji actually adds a complex layer of flavor that somehow enhances the natural flavor of the ingredients. I sound crazy, I know. You just have to try it for yourself.

So, you may ask - why isn't everyone making their own shio koji and using it to replace salt when cooking? The answer is simple; it takes a total of 10 days to make one batch and there is a texture issue that for some, may take some getting used to.


by Mai Fujii

200g koji rice*
40-50g fine, high-quality sea salt
3/4 - 1/4 C water
mason jar w/ lid, sanitized (at least 12oz)
disposable wooden chopsticks
saran wrap

Make it
Day 1 - Prep:
With clean hands, carefully break up your koji rice into small pieces and add to the bottom of the jar. Add salt and cover tightly with lid. Shake the ingredients till well incorporated. Pour enough water over the rice and salt to just cover the top. Using a clean pair of disposable chopsticks, stir the ingredients together (I like to push the chopstick to the bottom of the jar and gently fold upward). Continue to mix until the rice appears to be well saturated. Allow to stand for 5-10 minutes. You will notice the rice absorbed a lot of the water, so add just a bit more just to the surface of the rice. Stretch a small piece of saran wrap over the jar and use just the ring of the mason jar to cover. Use a toothpick to poke 4-5 holes in the saran wrap to allow air in the jar. Write the date on the jar.

Day 2 - Water:
On day two you will notice the rice has absorbed almost all the liquid in the jar and has expanded greatly. Add just a little bit more water to cover the surface of the rice. This will be the final day you will add anything to the jar. Use a fresh pair of chopsticks to stir until the water is incorporated. Replace saran wrap and ring to cover. Allow to sit in a warm area of your kitchen.

Day 3 - 10:
Mix, mix, mix. Mix the shio koji once a day for seven more days. As the days progress, you will notice a strong odor (similar to miso) coming from the jar. This is a good thing! At the end of day 10, the shio koji is ready to use. Some like to use the shio koji as is, but to bypass some of the textural issues, it is recommended to blend the shio koji. Pour into a blender and blend until smooth. Return to jar, cover tightly (with original lid and ring), and store in fridge. Will keep in fridge for up to three months!

*koji rice can be purchased at most Japanese specialty stores, on O‘ahu you can find it at Marukai or Nijiya.

Day One - Mixture has expanded slightly

Day Two - Rice consistency before adding water

Day 11 - Consistency after 10 days of mixing

Day Two - add additional water day!

Day Two - Rice consistency after adding water

Day 11 - Blended!


Shio Koji can be used in place of salt in many recipes. Be creative! Here is my favorite recipe so far - taught in class by Mai.

Shio Koji "Yakisoba"
Sautee one tray of thinly sliced pork in olive oil. When the pork has cooked through "deglaze" with one tablespoon of sake. Add half an onion sliced thin, and julienned carrots. When the carrots have softened, add 2 packets of fresh yakisoba noodles (we used Sun Noodle brand), hydrated wakame, and 2 tablespoons of shio koji. Right away you will notice a different and delicious smell! Stir with chopsticks to combine, and cook until noodles are heated through.

Stay tuned for more recipes that use shio koji!

MOA Wellness Center
600 Queen St. C-2
Honolulu, HI 96813