CiCi · Foods · Gluten-free soy sauce

Gluten-free soy sauce

The short answer

Most soy sauce is not gluten free. Conventional soy sauce is brewed from roughly equal parts soybean and wheat, and the wheat is fundamental to the fermentation. Tamari is the traditional wheat-free style, and it is the word to look for.

Soy sauce is the highest-frequency accidental exposure in restaurant eating, because it is in almost everything and almost nobody thinks of it as a wheat product.

The rule: the wheat is the recipe, not an additive

Tamari is the older style, a byproduct of miso production, made with little or no wheat. Most tamari sold today is labeled wheat-free or gluten-free, but not all of it is, and a small amount of wheat is permitted in some tamari. The word tamari is a strong signal. The gluten-free claim on the bottle is the guarantee.

Coconut aminos contain no soy and no wheat at all and are the safest substitute, at the cost of being noticeably sweeter.

The knock-on effect is what catches people. Soy sauce is the base of teriyaki, hoisin, oyster sauce, ponzu, most stir-fry sauces, most marinades, and a great deal of restaurant seasoning that never appears on a menu. A dish can look gluten free because there are no noodles in it and still be built on soy sauce.

Check it in the aisle instead

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At a glance

Sorted by what the answer actually is, rather than alphabetically — because the useful question in a shop is “which pile is this in.”

⛔ Contains gluten

Conventional soy sauce / shoyu
Brewed with wheat, typically half the grain bill.
Teriyaki sauce
Soy sauce base. Gluten-free versions exist but must say so.
Hoisin sauce
Usually contains wheat flour as well as soy sauce.
Oyster sauce
Commonly thickened with wheat starch and built on soy sauce.

⚠️ Depends — check the label

Tamari
Traditionally wheat-free, but confirm the gluten-free claim on the bottle.
Miso
Rice and soy miso are usually fine; barley miso (mugi) is not.
Ponzu
Citrus plus soy sauce. Inherits whichever soy sauce was used.

✓ Gluten free

Coconut aminos
No soy, no wheat. Sweeter than soy sauce.
Fish sauce
Anchovy and salt. Check only for added wheat in blended versions.

Common questions

Is all tamari gluten free?

Not automatically. Tamari is traditionally made with little or no wheat, and most tamari on shelves is labeled gluten-free, but some contains a small amount of wheat. Look for the gluten-free claim on the bottle.

Is soy sauce gluten free if it says "naturally brewed"?

No. "Naturally brewed" describes the fermentation method, not the ingredients. Conventional naturally brewed soy sauce is roughly half wheat.

Can I eat sushi if I have celiac disease?

Plain fish and rice are gluten free, but soy sauce, imitation crab (which is bound with wheat starch), tempura, eel sauce and many marinades are not. Bringing your own tamari and asking about imitation crab covers most of the risk.

Check it yourself

CiCi is not the authority on this. These are. Every link below goes to the regulator, charity or paper the answer above rests on.

Food Labeling; Gluten-Free Labeling of Fermented or Hydrolyzed FoodsU.S. Federal Register (Food and Drug Administration)The 2020 rule covering yoghurt, sauces, beer and other fermented or hydrolyzed foods, where gluten cannot be reliably measured, so compliance rests on records kept before fermentation.
Standard for Foods for Special Dietary Use for Persons Intolerant to Gluten (CXS 118-1979)FAO/WHO Codex Alimentarius CommissionThe international standard most national rules are built on: "gluten-free" at no more than 20 mg/kg, and a separate "reduced gluten" band of 20–100 mg/kg that may not be called gluten-free.
21 CFR 101.91 -- Gluten-free labeling of food.U.S. National Archives — Electronic Code of Federal RegulationsThe binding US regulation itself: it defines "gluten-containing grain", sets the "gluten-free" claim at less than 20 ppm, and states how manufacturers must demonstrate compliance.
Food Labeling; Gluten-Free Labeling of FoodsU.S. Federal Register (Food and Drug Administration)The 2013 final rule as published, with the full preamble explaining why FDA chose the 20 ppm figure and how it weighed evidence from people with coeliac disease.
Food AllergiesU.S. Food and Drug AdministrationHow the nine major allergens (including wheat) must be declared under FALCPA — useful because wheat-free allergen labelling is a separate legal duty from any gluten-free claim.
Gluten and Food LabelingU.S. Food and Drug AdministrationFDA's consumer explainer of what gluten is and which products the rule does and does not cover, including its 2017 survey finding only one of 702 samples out of compliance.

The scanner

Reading a page is fine. Standing in the aisle is the hard part.

This site answers the question you knew to ask. The app answers the one you didn't: the barley malt in a rice cereal, the wheat starch in a gummy. Scan the barcode, or photograph the panel when the barcode isn't in any database, and CiCi shows which words on the label produced the answer.

360,000+ packaged foods already read. Ingredient statement, allergen declaration and nutrition panel, each one assessed by the same rules you can see working on this page, so most scans are an instant answer rather than a lookup.
Unlimited scanning, about two seconds an answer. Fig and Spoonful both cut you off at five scans a month.
Carbs and the full nutrition panel on every scan. Total and net carbohydrate with the arithmetic shown. For the roughly 6% of people with type 1 diabetes who have coeliac disease too, that is two apps collapsed into one.
Your glutening log. Record a reaction and CiCi shows what those days had in common. It counts overlaps and never tells you what caused it.
Saved products. The regular shop in one place, so next week is not a re-scan of the same forty items.
Scanning happens on your device. No scan is ever attached to you, sold, or sent to an analytics service.

Try it free for 14 days →See pricing

14 days free, then $29.99 a year. Cheaper than Fig, and it does what three separate apps do. This website stays free forever either way: every answer on it, permanently, with no account.

Other food categories

Gluten-free breadThe bread aisle is where the most gluten exposures start. More of its marketing language sounds health-adjacent than in any other category, and none of that language means gluten-free.Gluten-free beerThis is the one category where a legal label distinction maps onto a real medical distinction, and almost nobody explains which is which.Gluten-free oatsOats are the only common food where the correct answer depends on which country you are standing in, and where a meaningful minority of people react even to perfectly clean oats.Gluten-free candyCandy is a good category to learn on, because it is small, the failure modes are few, and they recur everywhere else.Gluten-free sauces and condimentsA meal built entirely from naturally gluten-free ingredients is routinely undone at the last step by a spoonful of something from a jar.Gluten-free pastaThe noodle aisle is unusually forgiving once you know which base grain you are looking at, with one systematic exception.Gluten-free breakfast cerealCereal is the clearest demonstration of why an ingredient-list scanner that only looks for the word "wheat" is dangerous.Eating out gluten freeA published study found that a substantial share of restaurant food ordered as gluten free tested positive for gluten, with pizza and pasta the worst offenders by a wide margin.Gluten-free flourFlour is the category where a naturally gluten-free ingredient most often arrives contaminated, because milling equipment is expensive and rarely dedicated.Gluten in medications and supplementsThis is the category where the honest answer is most often "ask the manufacturer," and where scanners that give a confident verdict are least defensible.Gluten-free snacksA category where the base food is nearly always safe and the flavouring nearly always decides the answer.Gluten-free dairy and cheeseDairy is one of the safest aisles in the shop, which is why the few exceptions catch people off guard.Gluten-free meat and deliThis is the aisle where the regulatory technicality has real consequences, and almost no consumer guide mentions it.Gluten-free coffee, tea and drinksA category where the base drink is almost always fine and the additions decide the answer.Gluten-free bakingIn baking, the gluten-free question is less about safety and more about how a batter holds together without gluten.Gluten free for kids and schoolWritten for parents, and more about systems and social situations than about ingredient lists.Gluten free travelThe most useful travel tip is that a good translation card explains cross-contact rather than just naming gluten.Gluten-free frozen and convenience foodThe freezer aisle is where a naturally gluten-free food most often arrives with something added that nobody would have predicted.Gluten in cosmetics and household productsThis category is dominated by marketing, and the honest version saves people a great deal of unnecessary expense and worry.

Keep going

Every ingredient, A–ZLook up any single ingredient and see its classification, the reasoning, and the regulation behind it.ListsHidden sources of gluten, safe foods that sound risky, and more.LearnHow labels work, what cross-contact evidence shows, why oats are contested.Look up a product by barcodeEvery barcode CiCi can resolve has its own page.