Is Soy Sauce Keto Friendly?

Many Asian dishes would be woefully incomplete without a helping of soy sauce.

Fortunately, most of the most popular brands of soy sauce contain 1 g of net carbs or less for each 1 tablespoon serving. This makes it easy to fit into the keto diet as long as you're careful with your portion sizes. Even if you love the taste, resist the urge to drown your plate in soy sauce.

Soy sauce originated in China. Originally, they made it by fermenting soy beans, but as the food spread to Japan and other parts of the world, other ingredients have been added.

There are several major categories of soy sauce, and they're distinguished by the country of origin, the ingredients used, and the consistency of the sauce, from thick to thin.

Here's how the different soy sauce categories rank from most keto-friendly to least:

Soy sauce variety	Keto friendly?	Gluten-free?
Tamari (Japanese soy sauce)	Yes	Sometimes
Light Chinese soy sauce	Yes	No
Koikuchi (Japanese dark soy sauce)	Yes	No
Dark Chinese soy sauce	No	No
Usukuchi (Japanse light soy sauce)	No	No
Shiro (Japanese soy sauce)	No	No
Hydrolyzed soy sauce	No	No

Tamari (Japanese soy sauce): keto-friendly

Tamari is made mostly from soybeans with little to no wheat products. People who keep gluten free often choose tamari as their soy sauce of choice, but not all tamaris are gluten-free, so always check the label.

The typical tamari sauce contains 0.8 g of net carbs in each 1 tablespoon serving.

Light Chinese soy sauce: keto-friendly

Chinese light soy sauce is the most common type of soy sauce you'll find in Chinese restaurants and recipes. Usually, if a recipe refers to "soy sauce," without specifying light or dark, you can assume they're referring to light soy sauce.

Historically, light chinese soy sauce was made entirely from soy beans, but some varieties now contain wheat. Nevertheless, most brands of light Chinese soy sauce contain 1 g or less of net carbs per tablespoon.

Koikuchi (Japanese dark soy sauce): keto-friendly

Koikuchi, or dark Japanese soy sauce, is one of the most popular varieties of soy sauce in the US. It's made with a mixture of wheat and soy, but the wheat content is low enough that the carb count is still generally ~1 g of net carbs per 1 tablespoon serving.

Kikkoman's all-purpose soy sauce is a popular example of a Koikuchi soy sauce.

Dark Chinese soy sauce: not keto

Dark Chinese soy sauce is less common than its light counterpart, but most brands add sugar or molasses for flavor. There are a few keto-friendly brands of Chinese dark soy sauce, but check the label carefully to avoid ones with sugar-heavy ingredients.

Usukuchi (Japanse light soy sauce): not keto

Ukusuchi is a milder tasting of soy sauce, but it's made with mirin, a type of rice wine, so it generally has more sugar than other types of soy sauce.

Shiro (Japanese soy sauce): not keto

Shiro is like the inverse of tamari. While tamari is mostly soy, shiro is mostly wheat. Obviously, wheat-heavy products are a no-no on keto, so shiro is one of the least friendly forms of soy sauce.

Hydrolyzed soy sauce: not keto

Rather than fermenting soy beans, manufacturers produce hydrolyzed soy sauce through a chemical process in which they break down defatted soy meal. This is why some refer to hydrolyzed soy sauce as "chemical soy sauce."

You can identify hydrolyzed soy sauce by checking the ingredient label for "hydrolyzed soy protein" or something similar. La Choy, in particular, is a popular brand of hydrolyzed sauce sauce.

The process of manufacturing hydrolyzed soy sauce involves more artificial ingredients than other varieties, and has un-keto ingredients mixed in like corn syrup or caramel.

Sodium concerns

A common concern around soy sauce is its sodium content. The CDC recommends that adults eat no more than 2,300 mg of sodium per day.

Soy sauce is extremely high in sodium, with some varieties containing up to 1,000 mg per day in a single tablespoon. If you're concerned about your sodium intake, consider low-sodium brands of soy sauce.

Alternatives

If you want a similar taste to soy sauce but with fewer carbs, check out liquid aminos. Liquid aminos are produced either by fermenting coconut sap or by breaking down soy beans into amino acids. They contain close to 0 g of net carbs, and they're wheat-free.