For many people who have to switch to a gluten-free diet, saying goodbye to bread is like parting ways with an old friend.
Various gluten-free bread is available, but most don’t fill the void due to their taste and texture differences.
Sourdough bread has been touted as a safe option for those who avoid gluten. Many claim that the gluten in wheat sourdough or rye bread is broken down and more accessible to digest than in conventionally produced bread.
This article examines whether sourdough is a good option if you’re on a gluten-free diet.
Gluten in sourdough bread
Gluten is the name for a group of proteins found in wheat, rye, and barley. It causes damage to the intestinal lining in those with celiac disease, so it’s essential to avoid all sources of gluten if you have this condition.
Those with a gluten sensitivity or wheat allergy should also avoid gluten and wheat-containing foods.
The main ingredient in sourdough bread is wheat flour — which contains gluten.
While one lab analysis of the gluten in wheat sourdough bread has shown that it has less gluten than other wheat bread, the amount can vary.
This means there may still be unsafe levels of gluten in regular wheat sourdough bread.
However, gluten-free sourdough varieties are available from gluten-free flour like rice, sorghum, or teff.
The Food and Drug Administration (FDA) requires all labeled gluten-free products to have a gluten content below 20 parts per million (ppm).
Summary: If your sourdough bread contains wheat, rye, or barley, it also contains gluten. If you have to follow a strict gluten-free diet, only purchase sourdough bread made from gluten-free grains.
Effect of fermentation on gluten
Sourdough and regular bread are leavened differently.
While regular bread is leavened with packaged yeast, sourdough bread is leavened with Lactobacillus bacteria and wild yeasts.
This mixture of bacteria and wild yeast is called a sourdough starter. It’s made by mixing flour and water and letting it sit until microbes move in and ferment it.
During fermentation, these organisms digest the starches in the dough and produce lactic acid and carbon dioxide.
Fermentation gives sourdough its distinctive sour flavor and light, airy texture.
Gluten content might be lower
As the bacteria and yeast ferment the starches, they degrade some gluten.
The idea that sourdough bread is safe for those with celiac disease stems from a few small, controlled studies that found that eating sourdough didn’t cause symptoms or intestinal changes in those with this condition.
In one study, 13 people with celiac disease on a gluten-free diet ate either regular wheat bread, fermented sourdough so that part of the gluten was degraded, or sourdough that contained only 8 ppm of residual gluten.
After 60 days, the group eating the sourdough that contained 8 ppm of gluten reported no negative symptoms. It showed no adverse effects in their blood work or intestinal biopsies, while the other two groups reacted to the gluten.
It’s important to note that the low-gluten sourdough bread was produced under controlled conditions in a lab — not a home or food manufacturing kitchen.
Easier to digest?
The internet is full of reports from people with non-celiac gluten sensitivity who claim they don’t experience digestive symptoms after eating sourdough bread.
This may be because some of the proteins, starches, and inflammatory compounds in wheat-based products are easier to digest when fermented.
However, at this time, these claims aren’t backed by science.
What’s more, other compounds in the bread may cause issues for some people.
For example, alpha-amylase/trypsin inhibitors (ATIs) have been identified in gluten-containing products and appear to increase intestinal inflammation.
Suggested read: 13 foods that cause bloating (and what to eat instead)
Plus, carbs known as fermentable, oligo-, di-, mono-saccharides and polyols (FODMAPs) occur in grain- and gluten-containing products. They’re associated with symptoms of irritable bowel syndrome (IBS).
In a study of 26 people who followed a gluten-free diet for IBS, sourdough bread that had been fermented for more than 12 hours and showed lower levels of both ATIs and FODMAPs was not any better tolerated than regular bread.
Thus, the digestibility of sourdough bread may depend on the individual and various factors.
Summary: The fermentation process used to make sourdough bread breaks down some of wheat’s gluten and inflammatory compounds. However, it still contains some gluten, and no scientific evidence suggests it’s easier to digest.
Where to find gluten-free sourdough bread
There are several brands of ready-made gluten-free sourdough bread on the market.
The fermentation process improves gluten-free bread’s taste, texture, and shelf life so that you may prefer gluten-free sourdough over regular gluten-free bread.
But the easiest way is to bake it yourself:
Bake it yourself
If you want that fresh-from-the-oven taste and texture, consider baking your own gluten-free sourdough bread.
The easiest way to make it is to purchase a gluten-free starter, such as the one from Cultures For Health.
First, activate the starter, which takes about seven days. Here are the steps to follow:
- In a jar or bowl, mix the starter with about 1/4 cup (30 grams) of gluten-free flour and 1/4 cup (60 ml) of warm water.
- Cover the bowl and let it rest overnight at room temperature.
- The next day, add another 1/4 cup (30 grams) of gluten-free flour and 1/4 cup (60 ml) of warm water and mix well.
- Cover and let it rest again overnight at room temperature.
- For the next several days, discard part of the starter and feed it more flour and water every 12 hours. For the exact ratio, follow the instructions on your starter kit.
- When your starter is bubbly and doubles in size within about four hours, don’t discard any more. Instead, feed it two more times and then bake it or keep it in your refrigerator.
- If you continue to feed it more flour and water weekly, it will keep indefinitely.
To make gluten-free sourdough bread, combine the amount of starter your recipe calls for with additional gluten-free flour, water, and salt, let it ferment, and then rise for up to 24 hours. Then bake as directed.
Suggested read: Yeast substitutes: 3 easy alternatives
Summary: You can buy gluten-free sourdough bread or bake it yourself. It takes about a week to activate a sourdough starter, but once you have it, it’ll last indefinitely as long as you keep feeding it and store it in your refrigerator.
Wheat sourdough bread may contain less gluten than regular yeast bread, but it’s not gluten-free.
Regular sourdough bread isn’t safe if you’re on a gluten-free diet for celiac disease.
Instead, buy sourdough bread made with gluten-free grains, invest a few days, and activate your own gluten-free sourdough starter.
This way, you never have to miss a good loaf of bread again.