Home » What Is the Difference Between Dark Soy Sauce and Light Soy Sauce?
You are probably familiar with soy sauce, but did you know that there are many different types of soy sauce you can buy? In Japan, two main versions of soy sauce, "koikuchi (dark)" and "usukuchi (light)", are used most often for various reasons.

If you’ve ever had Asian food, you’ve undoubtedly had soy sauce. But did you know that there are many different types of it? The Japanese have their own version of this versatile sauce, and you may find you like it much better than the one you’re familiar with.

What Exactly Is Soy Sauce?

Put simply, it is made from a combination of fermented soybeans, wheat and a brine mixture. Just as there are many brewing and aging methods for wine and beer, so too are there variations in the process for making soy sauce. Korea, Japan, China, Indonesia and their many regions all have different versions.

Note: Mass-produced American-brand ones are typically made through a chemical process and are lacking in the rich flavors found in real one. Soy sauce that is traditionally made is aged for at least six months. Premium ones are aged much longer.

More than just a condiment, soy sauce has a history of more than 300 years. It can also be used in marinades or as a seasoning for some dishes. In Japan, most popular ones are “koikuchi (dark)” and “usukuchi (light)”.

What Is “Koikuchi” Dark Used For?

Dark soy sauce is the most common one in Japan. Although it may not always say it on the bottle, koikuchi is usually what you’ll find in most supermarkets and Japanese restaurants.

When recipes call for soy sauce, the standard ingredient to use is the dark one, unless otherwise specified. It is also the soy sauce of choice for dipping anything from sushi to spring rolls.

What Is “Usukuchi” Used For?

Light soy sauce is the second most popular one in Japan. Its typical use is to flavor or marinade a dish when you don’t want the deep color ruining the look of the dish. It is also important to remember that usukuchi is saltier than its dark counterpart.

It is also made with soy, wheat and salt, but the color is lightened through the addition of wheat gluten or fermented rice. A bottle of usukuchi is usually a bit pricier than the dark and may also be labeled “thin.”

Both koikuchi and usukuchi appear often in many Japanese recipes. Buying both types would be a good idea if you want to start trying authentic Japanese cooking.

Easy recipes only using basic Japanese ingredients here.