Is Gluten in Soy Sauce? A Celiac Dietitian Explains


After all, it’s just sauce made from soy, right? One of the biggest mistakes I see new celiacs make is eating soy sauce. That’s because while the name sounds gluten-free, most soy sauce products are actually made with wheat.

So if the soy sauce bottle reads something like “water, soybeans, wheat, salt” then it’s not’s gluten-free. And most soy sauce ingredients, like the regular Kikkoman Soy Sauce, read this way.

Why is There Wheat in Soy Sauce?

Now that we know there can be gluten in soy sauce, why is it there? According to San-J, an 8-generation soy sauce brewing company, adding wheat to soy sauce was originally a Japanese tradition that many Chinese soy sauces have adopted. This is why today, most soy sauce is brewed with wheat.

Typically, these soy sauces have a 50/50 ratio of soy and wheat. This provides a slightly sweeter flavor than more soy-based soy sauces like Tamari.

Speaking of Tamari, often Tamari will be a safer option than soy sauce because it’s a mostly soy-based sauce. But when shopping for Tamari, stay vigilant. Tamari can be made with small amounts of wheat too.

But How Much Gluten Though?

We know that wheat is often fermented with soy, but how much gluten is present? The answer isn’t cut and dry, as we have some research showing that even with wheat added to soy sauce, the gluten content of the ferment is <5ppm. Which would be considered celiac-safe. Some hypothesize that this is due to the hydrolysis (or breaking up of proteins) which removes the gluten.

This might be similar to the concept of gluten-removed beer being gluten-free. The process is similar, where the gluten protein is broken down so it’s considered gluten-free.

However, similar to gluten-removed beers (learn more about them here), we don’t have the proper testing measures yet to really verify this safety. And this is a limitation this study on the gluten content of soy sauce emphasizes. So for now, it is my professional opinion that fermented products are only safe for celiac disease when distilled or made with gluten-free ingredients. That includes soy sauce. So no, don’t eat the soy sauce that’s been made with wheat (at least not until we know more).

What Soy Sauces Don’t Have Gluten?

If we have to avoid soy sauces with wheat in them, which ones are actually gluten-free? We’re so glad you asked! Below is a list of some delicious gluten-free options for you to enjoy!

Is La Choy Gluten-free?

First up, many people wonder if there is gluten in La Choy products. While some of the bottles are marked gluten-free, other bottles aren’t.

The ingredients of this soy sauce are “water, salt, hydrolyzed soy protein, corn syrup, caramel color, potassium sorbate”. Regardless of gluten-free markings or now, all La Choy Soy Sauces appear to be gluten-free based on those ingredients.

Because no gluten is listed in the ingredients, there is no reason to believe La Choy Soy Sauces contain gluten. However, some people still report reactions. This is where working with a dietitian specializing in celiac and/or IBS can be helpful.

As often with celiac people immediately think they are reacting to gluten when often other food triggers may be present due to intestinal damage or other co-occurring conditions (like IBS).

The bottom line? La Choy Soy Sauce is gluten-free but if you think you reacted, discuss this with your dietitian to get to the root cause.

San-J Gluten-Free Soy Sauces 

San-J brews 100% soy-based Tamari. It’s a premium Japanese soy sauce made using small-batch fermentation methods passed down through the family for over 200 years. These soy sauces are less sweet than other kinds but they are just as delicious. They are a great gluten-free soy sauce option and they even sell packets of their soy sauce so you can travel easily with it.

Kikkoman Gluten-Free Soy Sauce

Another gluten-free soy sauce option is Kikkoman. It’s a little milder and sweeter than the other listed options because it’s not 100% soy based. Instead, Kikkoman substituted rice for wheat in their brew. If you’re looking for a more comparable option to the soy sauces you’re used to, then this is the one for you.

Are There Soy-Free Soy Sauces?

Gluten-filled and gluten-free soy sauces out of the way, are there soy sauce alternatives for people who can’t tolerate soy and gluten? The answer is yes! While nothing will be the same, there are some great substitutes that will provide similar flavors.

Coconut Aminos

A soy-free and gluten-free alternative to soy sauce is a bottle of coconut aminos. Coconut aminos are essentially just fermented coconut blossom nectar and salt. It’s a sweeter taste but it has a similar umami profile. Many people prefer it over regular soy sauce.

Fish Sauce

Fish sauce is another soy-free and mostly gluten-free alternative to soy sauce. Essentially, it’s fermented fish, salt, and water. Just be careful as some fish sauce can still contain gluten.

Fish sauce has a much stronger and saltier flavor so be sure to taste test as you use it. However, it’s another great substitute if you’re craving that umami flavor from soy sauce but can’t have soy.

Is Soy Safe for People With Celiac?

Before we wrap up our conversation on gluten in soy sauce, I think it’s important to talk about the safety of soy for people with celiac disease. There is often talk about soy having cross-reactive proteins with gluten.

Essentially, people suspect that the proteins of soybeans are so similar to gluten that it can trigger a celiac reaction. Let me put your mind at ease and assure you that there is no clinical proof that cross-reactive proteins are a thing.

The only other food that may trigger a celiac reaction other than gluten, are some oat proteins. And this only occurs in a very small percentage of the celiac population.

So yes, soy is safe for people with celiac to eat. Unless the person with celiac has an intolerance or allergy to it. As always, if you are unsure if soy is suitable for you, discuss this with your dietitian.

Keeping Things Saucy…

Wrapping it up, yes, there is gluten in soy sauce – sometimes. That’s because soy sauce often is made with wheat. When looking for a sauce, look for ones that don’t list wheat as an ingredient.

And if you’re not reacting well to soy sauce in general, consider a soy-free alternative like gluten-free coconut aminos or gluten-free fish sauce.

Now we want to know, what’s your favorite way to use soy sauce?

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