It is true that the fermentation of wheat based dough with the combination of wild yeast and good bacteria works well to break down the gluten found in the wheat. In controlled experiments tests show that the measured gluten in fermented sourdough bread can be reduced to under 20 parts per million.
However, it is important to note that not every single batch of sourdough bread turns out the same. Currently, there is no standardization for fermentation or preparation of the dough. Without testing each and every loaf, it is impossible to know if all the gluten has been broken down. Additionally, in kitchens that are not completely gluten-free, wheat flour may have been used on the kneading or baking pans. Stray wheat flour in the kitchen can add a significant amount of unfermented gluten back into the bread.
While the amount added back in may seem small it is still significant. It is important to be aware that the cumulative effect of gluten that can trigger an autoimmune response.
For those who have gluten intolerance or are trying to reduce their gluten intake, traditional wheat sourdough may be a reasonable option – given that it does have significantly less gluten than other types of bread. However, until the process can be standardized and further studies are done, wheat based sourdough bread should be strictly off limits for those with celiac disease.
If you are a celiac or highly sensitive to gluten, however, no need to fret! It is possible to make a sourdough starter and bread completely out of gluten-free grains. A quick search brings up a ton of recipes – let us know if you decide to make a loaf using a gluten-free starter, we would love to hear about it!
If you don’t have time to make you own, gluten-free sourdough bread is available from The Whole Kitchen.