Heather Sliwinski

Is Soy Sauce Gluten-Free? No, And Why You Can't Test It With Nima

Asian food in to-go boxes Soy sauce is one of the oldest condiments, having been used for more than 3,000 years for food preservation and seasoning. Today, finding a meal without it in a Chinese or Japanese restaurant can be a challenge, and more and more restaurants outside of Asian influence are using soy sauce instead of salt to reduce sodium in dishes while maintaining the salty flavor. For instance, chefs may use soy sauce in items like sauces, dressings or marinades to add flavor to dishes without adding more sodium.   

Is soy sauce gluten-free?

No. Traditionally, soy sauce is made from four main ingredients: soybeans, wheat, salt and water. First, Aspergillus mold is added to cooked soybeans and wheat. Then, the mixture is combined with salt water and lactobacillus bacteria. Fermentation takes several months, so the soy and wheat proteins can break down — a process known as hydrolysis. Because the gluten in the soy sauce is now hydrolyzed, most of the current gluten-detecting technologies using antibodies, including Nima, are unable to find these smaller broken-down gluten particles. When gluten is broken down to these smaller particles, called peptides, they can still cause damage to celiac disease patients. Even though soy sauce does not have intact gluten, it can still elicit a reaction because these immunogenic peptides are still present.  

What is a gluten-free alternative to soy sauce?

An alternative to traditional soy sauce is tamari, made with soybeans, but little to no wheat, depending on the brand (check labels carefully). Tamari is thicker and less salty, but with stronger flavor than soy sauce. San-J makes regular, organic, reduced-sodium and travel-sized tamari-style soy sauces. Kikkoman, one of the more familiar soy sauce brands on the market, now offers gluten-free tamari-style soy sauce as well.* When dining out at restaurants, when also asking if food is gluten-free, it’s a good idea to ask if soy sauce is used in a dish. We’ve heard of restaurants soaking their french fries in soy sauce before deep frying them. You never know where it could be lurking unexpectedly!   *We are unable to verify that these products are truly gluten-free, so proceed with caution before trying any new products.
Nima Cookie

Join the Nima community

Every blog post is baked with love