Japanese Soy Sauce (Shoyu)

Soy sauce is a staple—and one of the most essential seasonings—in Japanese cooking. Whether you’re just getting started with Japanese cuisine or want to deepen your knowledge, this post will give you a quick overview of how it’s made, the different types, and how to use them!

Missing Japanese ingredients? Try these easy substitutes!

What Is Soy Sauce?

Soy sauce, or shoyu (醤油) in Japanese, is a dark, salty liquid made from soybeans, wheat, and salt. It’s fermented and aged for several months (sometimes even years), which gives it a deep umami flavor—savory, slightly sweet, and full of complexity.

You’ll find soy sauce in soups, stir-fries, marinades, dipping sauces—basically everywhere in Japanese cooking!

How Soy Sauce is Made

Here’s a simplified version of the traditional soy sauce-making process:

Mix the Ingredients
Blend steamed soybeans and roasted wheat.
Make Koji
A fermentation starter called tane koji is added to the mixture to create koji.
Fermentation
The koji is mixed with saltwater and placed in fermentation tanks. This mixture, called moromi, ferments for 6 months to several years, developing deep flavor and aroma.
Pressing
After fermentation, the moromi is pressed to extract the liquid soy sauce.
Pasteurization and Bottling
The extracted soy sauce is gently pasteurized to stop fermentation, then filtered and bottled.

Types of Soy Sauce

There are several varieties of shoyu (soy sauce) in Japan, each with its own unique flavor profile and culinary purpose. Here are the main types:

3 different soy sauce. — From left usukuchi, koikuchi, and tamari

Koikuchi (Dark Soy Sauce): Most common soy sauce. Dark in color, well-balanced umami and saltiness.
Usukuchi (Light Soy Sauce): Lighter in color but saltier than koikuchi. It’s used when you want to season without darkening the dish.
Saishikomi (Double-Brewed Soy Sauce): Brewed twice using soy sauce instead of water, resulting in a deeper color and richer flavor.
Tamari: Contains little or no wheat, making it suitable for gluten-free diets (check the label).
Shiro (White Soy Sauce): Made mostly with wheat and fewer soybeans, giving it a pale golden color.
Amakuchi (Sweet Soy Sauce): Sweeter and milder than regular soy sauce, with added sweeteners.

💡 Not sure which one to choose?
Choose koikuchi (dark soy sauce). It’s the most versatile and widely used in Japanese cooking.

Want to learn more? Check out Types of Soy Sauce in Japanese Cooking!

Where to Buy

You can find Japanese soy sauce at:

Japanese grocery stores
Asian supermarkets
Online retailers like Amazon or specialty Japanese food shops

Popular Japanese Soy Sauce Brands

Japanese soy sauce differs from Chinese and Korean soy sauces. It tends to be saltier and less sweet than the others. For authentic Japanese flavor, try one of these trusted brands:

Recipes Using Soy Sauce

Here are easy and delicious recipes to get you started:

Salad: Goma-ae (Japanese Sesame Salad), Tomato and Onion Salad, Tofu Salad with Seaweed
Soups and Stews: Wakame and Lettuce Soup, Simmered Kabocha, Oden Stew, Zosui (Japanese Rice Soup)
Stir-frying: Easy Teriyaki Japanese Eggplant, Stir-fried Cabbage, Seafood and Lettuce Fried Rice
Teriyaki: Teriyaki Japanese Eggplant, Teriyaki Mushroom Rice Bowl, Teriyaki Tofu

Your Questions Answered

Is shoyu vegan?

Soy sauce is naturally vegan since it’s made from soybeans, wheat, and salt. However, always check the label—some varieties may include dashi made from fish, like katsuobushi (bonito flakes).

How much should I use in a recipe?

Start with 1 to 2 teaspoons per serving, then adjust to taste.

Is soy sauce gluten-free?

Traditional soy sauce is not gluten-free because it’s made with wheat as one of the main ingredients.
However, there are gluten-free options available! For example, tamari: A type of Japanese soy sauce made with little to no wheat (check the label to be sure). Some brands also make specially labeled gluten-free soy sauces.