Culinary Chemistry: The Truth about Soy Sauce and Gluten Content
by Jenn Oliver
From the archives
Soy Sauce and: Now a Staple in Western Cuisine
Soy sauce has been around as a staple condiment in Asian cuisine for thousands of years, used for flavoring all manner of dishes and foods. It’s prized for the “umami” character it gives to the overall taste of a dish, and can have a wide range of subtle notes beyond the obvious saltiness.
For example, Japanese tamari is often wheat free (I stress, not always). Still, most of the soy sauces available on store shelves contain wheat. While there is some debate as to exactly how much gluten from wheat survives the fermentation and processing, the Celiac Disease Foundation Foundation does list soy sauce as a food that may contain gluten and needs to be verified. The Mayo Clinic also states that soy sauce should be avoided unless otherwise labeled. There is also considerable anecdotal evidence of experiences of people being “glutened” by soy sauce (my husband included). Therefore, for those who must eat gluten free, soy sauce immediately becomes a food that requires attention and is a complicated topic.
Thankfully, in part due to the rising popularity of the gluten-free diet, some gluten-free soy sauces exist and allow a gluten-sensitive person to bypass the issue entirely by choosing a true GF option. Kikkoman makes a gluten-free soy sauce, and San-J sells a very popular wheat-free tamari. Liquid aminos such as that made by Bragg, can also serve as a GF substitute for soy sauce. While it is incredibly helpful to those who must avoid gluten that such GF options are available, by and large most soy sauces still have some level of wheat in the ingredients, and their actual gluten content is quite suspect.
Another consequence of the increased visibility of the gluten-free condition is that “gluten free” has become a household term, and thus in recent years education about the gluten free diet has spread far and wide. This does not however mean that one should not be cautious. Even today, misinformed ideas about the presence of gluten in foods are abound, and thus a certain diligence is required for those that must be gluten free. One must always check all the labels of all foods listed in a recipe, maybe even calling a manufacturer or visiting a website online in order to be sure of the status of gluten presence (or absence). One must also read ingredients carefully and know which ingredients are “suspect”. It is not uncommon today to find “gluten free” labeled recipes that list soy sauce in the ingredients list, with no mention at all as to the major prevalence of wheat in the most commonly available soy sauces. Such a lack of clarification does a disservice to everyone, since well-intentioned friends and family members, or those new to the GF diet who are inexperienced in searching for “hidden gluten” in products, could potentially cause their loved ones to get sick. To play it safe, one should treat soy sauce as an off-limits food for GF folks, and instead use and/or provide soy sauces (or soy sauce alternatives) that are specifically labeled as gluten free.
Jenn Oliver writes our column Culinary Chemistry. She has a Ph.D. in science, where she explains the scientific aspects of what really goes on when you cook (the next Harold McGee?). She’s been running a gluten-free blog, Jenn Cuisine, since 2008 and her kitchen is more like a laboratory than a kitchen. She’s focuses her chemical calculations and experiments on figuring out how to make traditionally glutinous food gluten-free.