Tamari vs. Soy Sauce: What's the Difference?

With their similar dark hues and salty-umami flavor profiles, you may mistake soy sauce and tamari as one and the same—but these soy-based sauces have several key differences. Learn about the differences between soy sauce and tamari, including their production process, nutrition and more.

Tamari vs. Soy Sauce

What Is Tamari?

Tamari is a fermented soybean sauce with an umami-forward flavor. It's believed to have originated in China, but was popularized in Japan. When it was first produced, tamari was a byproduct of the miso-making process. Miso paste is formed by cooking and fermenting soybeans. When miso is left to ripen, a liquid byproduct is expelled—and that liquid is known as tamari, which means "that which accumulates."

Nowadays, in order to meet a commercial demand, tamari is produced by soaking and cooking the beans to create nuggets known as koji. Those nuggets are then placed in an incubation chamber before they get transferred to a fermentation tank. During the fermentation process, the koji mixes with salt and water to create a mash known as moromi. The moromi is then left to age for several months to develop its flavor, color and aroma. Finally, the moromi is pressed to extract the tamari.

What Is Soy Sauce?

Soy sauce is a fermented, umami-flavored sauce made from soybeans. It originated in China. It's made from four ingredients: water, soybeans, wheat and salt. Soy sauce has a similar production process to commercially made tamari, but the key differing ingredient is wheat. During the initial production stages, wheat and soybeans are cooked together before the koji is fermented with a saltwater brine, resulting in the moromi. After the moromi is left to age and develop, it is pressed to yield the soy sauce.

Nutrition of Tamari vs. Soy Sauce

According to the USDA, 1 tablespoon of tamari contains:

• Calories: 11
• Protein: 2 grams
• Total fat: 0 g
• Carbohydrates: 1 g
• Sugar: 0 g
• Sodium: 1,010 milligrams

According to the USDA, 1 tablespoon of soy sauce contains:

• Calories: 9
• Protein: 1 g
• Total fat: 0 g
• Carbohydrates: 1 g
• Sugar: 0 g
• Sodium: 878 mg

Tamari and soy sauce are both high in sodium, and when sodium is eaten in excess, it can lead to bloating, headaches and more. Luckily, most brands offer a low-sodium or reduced-sodium version, which is EatingWell's go-to choice in our recipes. While low-sodium soy sauce has the same calorie, protein, carb and fat nutrition profile as regular soy sauce, its sodium content is 42% less, as a 1-tablespoon serving contains 511 mg.

One key nutritional difference between soy sauce and tamari is gluten. Soy sauce is made with wheat, so it's not gluten-free—but tamari is. Since tamari is 100% soy-based, it's suitable for those with a gluten allergy or intolerance. Some brands, like Kikkoman, sell products labeled gluten-free soy sauce, where they swap the wheat for rice. If you have a gluten allergy, be sure to read the label.

When to Use Tamari vs. Soy Sauce

Soy sauce and tamari are often used interchangeably in recipes, but there are a few differences in flavor and texture. Due to its higher concentration of soy, tamari has a richer and smoother taste. It's also a little thicker than soy sauce, although both have an easy pourable consistency. You can swap out one for the other, though, especially if you follow a gluten-free diet.

Try tamari in recipes like Tamari-Ginger Meatball & Eggplant Casserole or Sesame Tamari Vinaigrette. Try soy sauce in recipes like Soy Sauce Eggs or Soy-Lime Roasted Tofu. However you use tamari or soy sauce, it is sure to add a delicious umami flavor to your dish.

The Bottom Line

Tamari and soy sauce are both made from fermented soybeans and add salty-umami flavor to dishes. While they can be used interchangeably in recipes, tamari is gluten-free while soy sauce is not. Choose the low-sodium or reduced-sodium versions of the sauces when possible to reduce your sodium intake.