Soy sauce

Soy sauce is high in histamine. It is made by fermenting soybeans (and usually wheat) for months, and that long fermentation is exactly what drives histamine up, so it is one of the higher-histamine condiments you can add to a dish.

Why soy sauce is rated high

The deep, savory flavor of soy sauce comes from months of fermentation, and the same microbes that break down the soy and wheat proteins into that rich taste also leave histamine behind in the finished liquid. It is not the soybean itself that is the problem: a fresh cooked soybean is a very different thing. The issue is what the aging process does to it. Because soy sauce is used in small splashes but is very concentrated, even a little can carry a meaningful amount.

What changes your risk

• Length of fermentation — traditionally brewed soy sauce is aged for many months, so it tends to sit at the higher end; there is no version of real fermented soy sauce that avoids this.
• Fresh vs. fermented form — plain cooked soybeans, edamame, or fresh tofu are a completely different situation from fermented soy sauce, since they skip the aging step that builds histamine.
• Other fermented soy sits high too — miso, tamari, and coconut aminos are also fermented, so swapping soy sauce for those usually does not lower your histamine load.
• Amount used — soy sauce is concentrated, so even a small pour adds up; a light hand matters more here than with most foods.
• Gluten — most soy sauce contains wheat, which is a separate issue for anyone avoiding gluten, on top of the histamine.

Lower-histamine alternatives

There is not a truly low-histamine version of soy sauce, since fermentation is the whole point of it. For salt and savory depth without the fermented amines, try a pinch of plain sea salt, fresh or dried herbs, a little garlic or ginger cooked into the dish, or a homemade broth reduced down from very fresh cooked poultry or fresh white fish. Skip the usual swaps people reach for like tamari, miso, coconut aminos, and fish sauce, because those are all fermented and tend to be high too.

How to lower the risk

If you are cooking for someone with histamine issues, the simplest move is to leave soy sauce out and build flavor another way: sea salt for saltiness, sauteed garlic and ginger for savoriness, and fresh herbs for brightness. When you eat out, remember that soy sauce hides in marinades, stir-fries, dumplings, and dipping sauces, so it is worth asking. Nothing about how you store or heat soy sauce lowers the histamine that already formed during fermentation.

Common questions

Is low-sodium or gluten-free soy sauce lower in histamine?

No. Low-sodium and gluten-free versions are still fermented, so the histamine is much the same. Gluten-free (like some tamari) only helps if your concern is wheat, not histamine.

Is tamari a safe substitute for soy sauce?

Not for histamine. Tamari is fermented like regular soy sauce, so it tends to be high too. Its main advantage is being wheat-free, not lower in histamine.

Are plain soybeans, tofu, or edamame also high?

They are a different story because they are not fermented. Fresh cooked soybeans, edamame, and fresh tofu are generally much better tolerated than soy sauce, though some people are sensitive to soy in general.

Does cooking soy sauce into a dish burn off the histamine?

No. Heat can change the flavor but does not remove histamine that already formed during fermentation, so cooked-in soy sauce still counts.