June 27, 2014

Could fermented sourdough be a viable alternative for those with gluten intolerance?  Studies suggest that it’s quite possible!

Ancient cultures have traditionally fermented bread over lengthy periods of time before baking.  One example of this is sourdough– a pioneer food highly regarded internationally for its portability and nutritiousness. The Californians called it sourdough, the cattle country called it Chuck Wagon Bread, and South Dakotans called it “Cellar Biscuits”.  Germans have “Sauerteig”, and Africans use a wild yeast called “Most”.

Now for the best part… where the old (folk tradition) and new (science) overlap!

In a 2004 Italian study [1], 17 human subjects with Celiac Sprue (CS) were able to tolerate a wheat-based sourdough bread without any adverse reaction.


A sourdough starter was made with 30% wheat flour, then left to ferment for 24 hours using specific strains of Lactobacillus for 24 hours; after which the highly allergenic components of gluten (albumin, globulin, and gliadin) had been almost completely transformed into much smaller, far less allergenic elements.  Next, the starter was blended with oat, millet, and buckwheat flours, then fermented for another 2 hours and baked at 220˚C for 20 minutes.  A second bread was made using the same flour mixture with the addition of baker’s yeast.


A group of CS patients who had been gluten free for a minimum of two years were recruited for the study.   After an overnight fast, their baseline intestinal permeability was tested and recorded.  They were then asked to randomly eat one of the two breads over a period of 2 days, after which intestinal permeability was re-tested and recorded again. Thirteen of the 17 CS patients showed an obvious increase in intestinal permeability after ingestion of the baker’s yeast bread.  When fed the sourdough bread, these same 13 patients had intestinal permeability values that did not differ significantly from their baseline values. The remaining four CS patients did not respond to either bread.


Yet another study [3] revealed that fermenting wheat and rye flours with specific strains of Lactobacillus over a 12-24 hour period enzymatically hydrolyzed (broke down) most of the offending gluten containing proteins.


It is also interesting to note that fermentation has the potential to produce vitamin B12, among others, making breads more nutritious and shelf stable. While the levels produced by traditional methods are far below the amount required by humans,  a 2008 study [2]  showed promise in this area by successfully using a metabolic engineering technique to optimize the amount of folic acid and B12 produced by fermentation of melons.  Further research is required to perfect and expand this technique to include other vitamins.


Further, large-scale studies are being conducted to identify and perfect the techniques required to industrialize these bread-making processes.


Coming across these articles immediately made me think of Los Angeles scientist turned breadmaker, Jack Bezian, who has been making small batch sourdoughs the slow, old-fashioned way since 1985.  He is a weekly fixture at the Hollywood, Pasadena, and Santa Monica Farmer’s markets.  I had enjoyed Bezian’s bread before, but wasn’t initially sold on his “weird science” until I began to research for myself.  You can catch my recent interview at 20 Four Carrots.  Admittedly, I’ve become newly addicted to the organic zucchini onion bagels.  If you prefer to make your own, try this great recipe from Nourished Kitchen [4].