My diet:

Soy sauce

No E-numberFlavor enhancersOrigin: Fermented
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Pick your family’s diets in the bar above.

Every diet

VeganYes

Standard soy sauce is soy, wheat and salt. A sauce with fish lists the fish.

Gluten-freeDepends

Wheat is in most soy sauce. Tamari and gluten-free labels are the exception.

HalalDepends

Fermentation leaves a trace of alcohol, so halal acceptance depends on the certifier.

KosherDepends

Kosher soy sauce needs certification. Soy is kitniyot for some Passover customs.

KetoYes

A splash of soy sauce has negligible carbohydrate.

Low-FODMAPDepends

A teaspoon is often tolerated. A large pour of soy sauce is high FODMAP.

The short answer
Soy sauce is a fermented soybean seasoning. It is vegan when no fish was added. It is not gluten-free unless it is tamari or labeled gluten-free. A teaspoon is the usual low-FODMAP amount. A heavy pour is not.
Use in moderation

Safe in small amounts; may bother some people or raise blood sugar.

E-numberNone
Comes fromFermented
What it doesFlavor enhancers
Glycemic index—
Daily limitNot set
Also calledSoy sauce, Shoyu

Rules by country

🇺🇸 US FDANot evaluated as an additive
🇪🇺 European UnionNot evaluated as an additive
🇨🇦 Health CanadaNot evaluated as an additive
CaliforniaNo extra rules

Soy sauce is a food, not an E-number. Gluten-free claims belong only on tamari or other sauces brewed without wheat and tested. The sodium is high in every style. Trace alcohol from the fermentation is why some halal certifiers want a specific approval.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

Brewed sauce takes months. The bottle that lists hydrolyzed soy protein, caramel color and salt was not brewed that way. Both can say soy sauce on the front. The ingredient line is where they part.

Where it comes from: Soy sauce is soybeans and, usually, wheat, fermented in brine with koji mold and then aged. Tamari is the style brewed with little or no wheat. A chemically hydrolyzed soy seasoning is a different, faster product and is closer to hydrolyzed vegetable protein.

Why it’s in food

  • Salts a stir-fry
  • Builds a marinade
  • Finishes a soup
  • Colors a glaze

Often found in

Stir-friesMarinadesSushi riceDipping saucesNoodle bowlsBraises

Also listed as: Soy sauce, Shoyu, Soya sauce, Tamari, Soy sauce powder

Health & gut impact

SodiumConcern

A tablespoon of soy sauce can carry a large share of a day's sodium. Low-sodium soy sauce is the same seasoning fermented or diluted to a lower salt.

Typical sodium content of soy sauce

Wheat in the brewConcern

Standard soy sauce is brewed with wheat. Tamari and gluten-free shoyu are the bottles a celiac kitchen can use.

Brewing of shoyu versus tamari

What can I use instead?

Yeast extract

Ratio: A savory paste when soy and wheat are both a problem

Best for: Soups

Salt

Ratio: When all you needed was salinity

Best for: Cooking

Related

More flavor enhancers:

Artificial flavors (Artificial flavoring)Artificial flavor means the aroma was synthesized, not extracted from the food it tastes like. The category is allowed. Vegan, halal and kosher status still depends on the carrier.Use in moderationBrewer's yeastBrewer's yeast is yeast left over from making beer. It is bitter, it may contain barley gluten, and it is not the cheesy flake called nutritional yeast.Use in moderationCalcium inosinate E633Calcium inosinate (E633) is a savory flavor booster related to disodium inosinate, used alongside MSG in snacks and stock products. It is gluten-free, but vegan, halal and kosher status depends on whether it was made by fermentation or from animal tissue.Generally safeDiacetyl (Butanedione)Diacetyl is the buttery flavor molecule. The FDA lists it as a GRAS flavor. Breathing the vapor at work has harmed lungs. Eating the trace in a food is the exposure the GRAS rule is about.Use in moderation

Common questions

Is soy sauce gluten-free?

Traditional soy sauce is brewed with wheat. Use tamari or a sauce labeled gluten-free.

Is soy sauce vegan?

The basic brew is soy, wheat, salt and mold. A few sauces add bonito or other fish, which will be in the ingredient list.

Is Soy sauce safe?

Use in moderation (68/100). Soy sauce is a food, not an E-number. Gluten-free claims belong only on tamari or other sauces brewed without wheat and tested. The sodium is high in every style. Trace alcohol from the fermentation is why some halal certifiers want a specific approval.

Is Soy sauce vegan?

Yes. Standard soy sauce is soy, wheat and salt. A sauce with fish lists the fish.

Is Soy sauce gluten-free?

Depends. Wheat is in most soy sauce. Tamari and gluten-free labels are the exception.

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Scientific sources & regulatory citations
  • Typical sodium content of soy sauce
  • Brewing of shoyu versus tamari