Japanese Shio Koji: A Gluten-Free Amino Sauce

Shio koji is a salty condiment related to miso, tamari, and soy sauce. Here’s how to make this naturally gluten-free liquid aminos!

I’ve thought about making tamari or a wheat-free soy sauce several times. However, every time I look into it, I decide it’s too much work. I like fermenting, but I’m not into fermenting something that needs daily attention and stirring. 😉

Shio koji is my happy alternative. It’s a quick ferment that is SOO simple. It’s a perfect zero-waste option for liquid aminios!

Even if you’re new to fermenting, this recipe is for you. It is that easy.

How to use shio koji

All koji-based ferments are perfect for bringing umami to your meals.

Shio koji has two forms:

1. A thick paste that includes the fermented rice.
2. Strained liquid amino acids.

Thick paste

The thick paste that includes the blended rice has a chalky texture that makes it better for coating and culturing other ferments rather than adding it to dishes.

• The traditional way to use shio koji is to marinate meat. This is because it is packed with enzymes that help break down proteins. It doesn’t only flavor meat, but softens it as well (I’m mostly vegetarian… so I’m taking this info from one of my favorite fellow fermenters, Holly Davis).
• It can also be used as a culture for other ferments. Any recipe that calls for miso paste can be fermented with shio koji. I particularly recommend using it to ferment tofu. The resulting tofu spread is a flavorful vegan condiment.
• Whatever you do, don’t throw out the rice! Here are some easy ways to use this nutrient-packed product:
  • Add it to smoothies (though only in small amounts as it is quite salty).
  • Make pickled vegetables.
  • Use it to flavor soups and stews (as described in the liquid aminos section below).

Strained liquid amino acids

Traditionally, shio koji is always used as a thick paste. However, I really wanted a gluten-free, zero-waste alternative to my usual soy sauce. This liquid amino sauce isn’t the same as soy or tamari… it has a sweeter flavor and lacks the earthiness of soy sauce. Regardless, it’s a pretty good substitute for anyone wanting to avoid the cost of buying gluten-free soy sauce.

• Strained liquid amino acids can replace salt in a dish. If you followed my recipe below, then you can use double the amount of liquid aminos. For example, 1 tsp of salt can be replaced with 2 tsp of shio koji.
• Add it to soups and stews as a bouillon replacement. It adds a ton of flavor and salt.
• Guacamole really benefits from the addition of this amino sauce. Fermenting guacamole not only helps it last longer, it also stops it from going brown!

How to know when your shio koji is ready?

I’ll admit, fermentation is a bit of an art form. Deciding when to bottle your cider or serve your pickled vegetables, depends on the Flavor, Texture, and Smell.

Shio koji is exactly the same… As a mold-based ferment, it will ferment fast in warm weather and slow down in cooler weather.

The best way to know when it is done is by the flavor.

1. Start to taste it after 7 days of fermenting. Since you have to stir it every day, simply lick the spoon when you are done.
2. At first, it will just taste salty… so salty you won’t really enjoy it.
3. As it ferments the flavor will become richer and sweeter. It’s ready when you lick the spoon and don’t just taste salt but rather a sweet and rich flavor.