A few weeks ago I ran this comic at Mimi & Eunice:
I’ve long suspected that soy sauce could contain only small traces of wheat, so I did a little online research. Surprisingly, I found only one item that addressed the gluten content of soy sauce directly, and found it contains none at all:
Gluten analysis of two popular soy sauces
We sent a sample of soy sauce of the brands Kikkoman and Lima to an external laboratory to determine gluten levels. In both samples the gluten content was below detection limit of 5ppm (see report). According to a new European legislation, which will only be fully implemented in 2012, gluten-free foodstuffs should contain less than 20 ppm gluten. The FDA also proposes a limit of 20 ppm. This means that our two tested products may be considered as gluten-free soy sauce. link
The article contains a link to a lab report which appears to be Belgian. It’s strong evidence, but celiac organizations are still claiming soy sauce contains gluten, which leads trolls to leave furious comments at mimiandeunice.com and my Facebook page for daring to suggest otherwise.
I’d like to clear up the soy sauce confusion once and for all. A Belgian lab report makes one data point, but more data points are needed, especially because these substances may differ between the US and Europe. What I’d like is an analysis of several brands of American soy sauce, both conventional shoyu (derived from wheat ingredients) and “gluten-free” tamari. Also both fancy health food store brands, and cheap run of the mill supermarket kinds. What would really be helpful is a brand-by-brand chart the wheat-sensitive could refer to.
So, is there an analytic chemist in the house? A chemistry grad student? A biochem hacker space with time and resources on their hands? I’m certainly not a chemist, but if you produce such a report you’ll have my undying gratitude and whatever publicity I and Mimi & Eunice can muster. Also, you’d be doing good for the world.