It seems like everyone I know has a sourdough starter, a hobby inspired by the pandemic and countless wonderful social media posts and pictures. While I am a big fan of sourdough bread and various sourdough products (pancakes, biscuits, crackers…), it isn’t something that can be safely eaten by someone with celiac disease or nonceliac gluten sensitivity.
Why, then, it is often promoted as harmless for someone avoiding gluten? Because of misinformation and misunderstanding of the fermentation process. Fermentation is the process of breaking down a substance (in this case, flour, but could also apply to grains to make beer or other food substances) by microorganisms – you know, little bacteria and yeasts that love to feed on carbohydrates to produce a foaming mixture of carbon dioxide and bubbles. What’s exciting about fermenting food is the production of beneficial microorganisms that act as prebiotics and probiotics to aid our digestion and overall health.
In making sourdough bread, here is how fermentation occurs: flour and water are mixed together and left to sit for a day or two. Enzymes in the flour start to break down its starches into smaller chains of carbohydrates and sugars, producing yeast and bacteria, mostly beneficial lactobacilli. The dough starts to sour, creating a lower pH that causes harmful bugs to disappear while yeast and good bacteria continue to grow, along with gas bubbles and a fruit (some would say vinegary) smell. The baker adds more flour and water over a few days, allowing the starter culture to continue to develop.
If you like science, click here for a good Food for Thought article from NPR.
With all this said, homemade sourdough bread is a nice alternative to other breads, as it contains beneficial prebiotics, a simple unprocessed listed of ingredients (flour, water and salt), and a variety of nutrients such as protein, vitamins and minerals.
But for gluten-free eaters, there is still gluten present that can cause problems, whether you have celiac disease or non-celiac gluten sensitivity. Research is a mixed bag. Most scientists say we don’t have enough information, and remind us that the symptoms of gluten reactions in the body may be undetectable. Some older small studies found limited negative impact, while other more recent studies don’t recommend it. One explains that gluten content in fermented foods cannot be quantified (published paper here), calling for additional research before conclusions are made.
A nice option is making gluten-free sourdough bread! You can make your baked goods with GF flours such as millet, oat, brown rice, and tapioca flour, or even a 1-for-1 GF flour, as long as you use a GF starter. There are several GF sourdough starter recipes online; here are three I recommend (I don’t get paid by these companies!):
If you have celiac disease, you should avoid gluten in any form, including sourdough bread made with gluten containing flour. If you have non-celiac gluten intolerance and feel confident in your ability to recognize symptoms, start with a small serving of sourdough bread to determine your reactions. In both cases, talk to your doctor or dietitian for additional information.
What does a dietitian, nutritionist, and health professional do when she discovers she has to avoid gluten? I mean, avoid it to prevent painful symptoms, not to follow a trend!