Is sourdough bread gluten free? And other common questions

When I began considering the types of bread that I wanted to craft and share with our community, naturally leavened (i.e. ‘sourdough’) bread quickly rose (no pun intended) to the top of the list. 

Cultivating and maintaining a sourdough starter is the key component for the natural leavening process. We utilize a slow fermentation process – meaning we ferment our dough for a total of 18 hours which includes 4-5 hours of bulk fermentation followed by a 12-14 hour cold fermentation of the individual loaves. Through this slow process, the bread acquires probiotic (healthy bacteria) and prebiotic properties, in addition to its characteristic ‘sour’ flavor.

Providing my customers with a fresh-baked loaf of bread that both tasted good and delivered health benefits sounded like the perfect combination. 

So, is sourdough bread gluten free? 

No, it’s not. I make my sourdough bread with a variety of locally sourced flours. These all contain gluten in varying degrees. The natural fermentation process, however, benefits those with gluten sensitivity or those who are trying to limit gluten in their diet. Think of our breads as ‘low gluten.' Customers who have struggled with the gluten in commercial breads find they can consume our bread without the negative digestive impact they may have experienced in the past. 

The short answer – gluten free? No. Gluten friendly? Yes.

How healthy is sourdough bread?

This topic leads to another popular area of discussion – how healthy is sourdough bread?  Relative to commercially produced breads, even those made with whole grains, sourdough is packed with health benefits. 

Supports blood sugar control 

This is especially important for people who live with diabetes. Sourdough bread has a lower glycemic index than white bread, so it doesn’t increase blood sugar levels as quickly. How? Because the fermentation process makes starch less available for digestion and absorption into the blood stream.

My customer Tony lives with diabetes and has reported that he has far lower glucose spikes when he eats our bread. He can enjoy our bread while remaining within the acceptable range set by his endocrinologist. 

Supports a healthy gut microbiome

According to an article published by the Mayo Clinic in October 2024, natural fermentation creates healthy bacteria, which thus creates fiber and prebiotics. Both of these feed into good bacteria in your gut. And good bacteria in your gut lead to improved digestion, better energy levels, and fewer instances of indigestion and bloating.

Easily digested

Again, let’s hear it for fermentation! The slow fermentation process breaks down the gluten as well as decreases the amounts of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) carbohydrates in the bread. The small intestine apparently does not do a great job of absorbing FODMAP carbs, especially the fructans. 

Fermentation makes digestion easier and has proven beneficial for those with digestive disorders such as irritable bowel syndrome (IBS) and for individuals who follow a low-FODMAP diet. Nikki, a customer who is on a low FODMAP diet, summarized her bread experience in this way: 

Knowing what’s in your bread is so important – that’s why I list my ingredients on my bread bag labels and on the website. I want my customers to know exactly what they’re eating, and that they can trust they’re getting a quality bread made with the best local ingredients available.

Promotes healthy aging

A 2019 review in the journal Nutrients found that fermented grain-based products, like sourdough, have antioxidant, anti-hypertensive, anti-diabetic and FODMAP-reducing qualities.

Other common sourdough questions

Although ‘Is sourdough bread gluten free?’ is the most common question I hear, I thought I’d share some other questions that I’m often asked, either at the farmers market on a Sunday, through email or even from my vendors.

What’s in your starter?  

I created my starter in 2020, using a combination of tap water, organic bread flour, and whole rye flour (along with naturally occurring wild yeast and beneficial bacteria). I’ve found this combination produces a starter which consistently provides a strong leavening ‘engine’ for our breads.  

Does sourdough bread really taste sour? 

It depends – remember sourdough refers to a method of making bread, not a flavor. The amount of ‘sourness’ comes from the lactic and acetic acids produced during fermentation. Generally, the longer and warmer the fermentation, the sourer the bread will be.  

We cold proof our breads for 12+ hours to allow flavor and texture to develop, with a relatively mild sourness compared to what you may have experienced with other sourdough. 

Is there such a thing as gluten-free sourdough bread? 

Yes, there is.

Do you plan to offer it to your customers? 

No, not at this time. A gluten-free recipe would require an entirely different starter and baking process. As mentioned above, we feel our bread doesn’t need to be gluten-free to deliver substantial health benefits.  

Do you ever bake birthday cakes? 

I get asked this question more often than you might think. The ‘bakery’ part of the business’s name suggests we also offer a wide variety of non-bread offerings… But no, I don’t bake birthday cakes!

References

• 2021 review in the journal Microorganisms 
• 2019 review in the journal Nutrients 

NOTE: The information included in this article is for educational purposes only, and does not substitute for professional medical advice. Please consult your doctor if you have concerns or questions about any of this content specific to your own health and dietary situation.

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