Is Sourdough Bread Low FODMAP?

Is Sourdough Bread Low FODMAP?

Yes, authentic sourdough bread is low FODMAP. When made using traditional long fermentation methods (12+ hours), sourdough bread made with wheat or spelt flour becomes low FODMAP at a serving of 2 slices (72g). This is exceptional because regular wheat bread is high FODMAP even at just 1-2 slices.

The key difference is the fermentation process. During the long rise, bacteria and wild yeast break down the fructans in wheat flour, dramatically reducing the FODMAP content. This makes properly fermented sourdough one of the few wheat-based breads safe for people with IBS.

However, not all sourdough is created equal - the fermentation time and method matter significantly for FODMAP content.

Safe Serving Size

According to Monash University, authentic wheat sourdough fermented for 12+ hours is low FODMAP at 2 slices. Spelt sourdough made with similar fermentation is also low FODMAP at 2 slices.

The Pocket Storehouse brand in Australia has tested low FODMAP sourdough at 2 slices. Certain brands like Inéwa in Canada also produce certified low FODMAP sourdough.

Why Is Sourdough Different from Regular Bread?

The secret lies in fermentation. Here’s why sourdough is special:

Traditional Bread Making (High FODMAP)

• Uses commercial yeast for quick rising (1-3 hours)
• Short fermentation doesn’t break down fructans
• Wheat fructans remain intact
• Result: High FODMAP, triggers IBS symptoms

Authentic Sourdough (Low FODMAP)

• Uses wild yeast and lactic acid bacteria (sourdough starter)
• Long fermentation (12-24+ hours)
• Bacteria pre-digest fructans in the dough
• Lactic acid bacteria consume the FODMAPs as food
• Result: Significantly reduced fructans, low FODMAP

The science: Research published in 2018 found that bread fermented for 12+ hours had fructan levels reduced by up to 90% compared to 2-hour fermentation. The longer the fermentation, the more fructans are broken down.

This is why artisan sourdough made with time-intensive traditional methods can be tolerated by many people with IBS who cannot eat regular wheat bread.

How to Identify True Low FODMAP Sourdough

Not all bread labeled “sourdough” is low FODMAP. Many commercial producers use shortcuts that don’t provide the same benefits:

Signs of Authentic Low FODMAP Sourdough:

Look for:

• Made with sourdough starter (not commercial yeast)
• Long fermentation time (12+ hours, ideally 24+ hours)
• Artisan or bakery-made
• Tangy, complex flavor
• Dense, chewy texture
• Irregular holes in the crumb
• Labels mentioning “traditional,” “authentic,” or “long-fermented”
• Low FODMAP certification (brands like BFree, Schär, COBS Bread LowFOD)

Red flags (likely High FODMAP):

• Ingredients list includes “yeast” in addition to starter
• Mass-produced supermarket brand
• Very soft, fluffy texture (like sandwich bread)
• Mild flavor (lacks sourdough tang)
• No mention of fermentation time
• Made quickly (under 6 hours)

Why Commercial Sourdough Often Isn’t Low FODMAP

Many grocery store “sourdoughs” are made with:

• Sourdough flavoring or additives
• Vinegar or citric acid for tang (not from fermentation)
• Commercial yeast for faster rising
• Short fermentation (2-4 hours)

These shortcuts create bread that tastes like sourdough but hasn’t had the long fermentation needed to break down FODMAPs.

Best Types of Sourdough for Low FODMAP Diet

Wheat Sourdough (Traditional)

Low FODMAP: Yes, at 2 slices (72g) if properly fermented Made from wheat flour with long fermentation. This is the most common type of authentic sourdough. Look for bakeries that specialize in traditional methods.

Tested brands:

• The Pocket Storehouse (Australia) - Authentic Wheat Sourdough Bread

Spelt Sourdough

Low FODMAP: Yes, at 2 slices (72-74g) if properly fermented Spelt is an ancient grain related to wheat. It naturally has slightly lower fructans than modern wheat, and when made into sourdough, it becomes low FODMAP.

Tested brands:

• The Pocket Storehouse (Australia) - Spelt Sourdough, Organic
• Inéwa (Canada) - 100% Spelt Sourdough Bread
• Inéwa (Canada) - Spelt & Buckwheat Sourdough

Gluten-Free Sourdough

Low FODMAP: Depends on ingredients Some bakeries make gluten-free sourdough from rice flour, buckwheat, or other gluten-free grains. While these don’t contain wheat fructans, check other ingredients:

• Avoid inulin or chicory root fiber (high FODMAP)
• Watch for high FODMAP flours or additives
• Brands like Schär make gluten-free sourdough products that are low FODMAP certified

White vs. Whole Wheat Sourdough

Both can be low FODMAP if properly fermented, but:

• White sourdough - Easier to digest, lower fiber
• Whole wheat sourdough - Higher fiber and nutrients, may be harder to tolerate during IBS flares

Start with white sourdough during elimination, then try whole wheat if desired.

How to Find or Make Low FODMAP Sourdough

Where to Buy Low FODMAP Sourdough

1. Artisan Bakeries Call ahead and ask about their sourdough process:

• “Do you use a sourdough starter?”
• “How long do you ferment the dough?”
• “Do you add commercial yeast in addition to starter?”

Look for bakeries that ferment for at least 12 hours, ideally 24+ hours.

2. Farmers Markets Small-batch bakers at farmers markets often use traditional methods. Ask about their fermentation process.

3. Certified Low FODMAP Brands Some brands make specifically low FODMAP sourdough:

• BFree (various countries)
• Schär - Sourdough products (gluten-free)
• COBS Bread - LowFOD line (Canada, US)
• Bakers Delight - LowFOD line (Australia, New Zealand)
• The Pocket Storehouse (Australia)
• Inéwa (Canada)

4. Online Ordering Some low FODMAP bakeries ship nationwide:

• Check the Monash University low FODMAP certified products list
• Search for “low FODMAP sourdough” + your country

Making Your Own Low FODMAP Sourdough

Making sourdough at home ensures proper fermentation:

Basic Process:

1. Create or obtain a sourdough starter (flour + water + wild yeast)
2. Feed the starter regularly to keep it active
3. Mix starter with flour, water, and salt
4. Ferment for 12-24+ hours (longer = lower FODMAP)
5. Shape and bake

Tips:

• Aim for at least 12 hours of fermentation, preferably 18-24 hours
• Cooler temperatures = slower fermentation = more FODMAP breakdown
• Use white wheat flour or spelt flour
• Don’t add commercial yeast (defeats the purpose)

Resources:

• “The Perfect Loaf” blog has excellent sourdough tutorials
• r/Sourdough community on Reddit
• Books like “Flour Water Salt Yeast” by Ken Forkish

Making sourdough requires patience and practice, but it’s the best way to guarantee low FODMAP bread.

Tips for Eating Sourdough on a Low FODMAP Diet

1. Verify Authenticity

Always confirm the bread was made with long fermentation. When in doubt, assume commercial sourdough is high FODMAP unless proven otherwise.

2. Stick to 2 Slices per Serving

Even authentic sourdough may increase in FODMAPs at larger portions. Stick to the tested serving size of 2 slices.

3. Choose Low FODMAP Toppings

Make sure your toppings don’t add FODMAPs:

Safe toppings:

• Peanut butter or almond butter
• Lactose-free butter
• Eggs (fried, scrambled, poached)
• Hard cheeses (cheddar, Swiss, parmesan)
• Lactose-free cream cheese
• Sliced tomato, cucumber, lettuce
• Smoked salmon
• Tuna or chicken salad (watch for garlic/onion)
• Jam (check sugar content - 1-2 tablespoons)

Avoid:

• Honey (high in fructose)
• Regular cream cheese (lactose)
• Avocado (limit to 1/8 whole per serving)
• Hummus (chickpeas are high FODMAP)

4. Watch for FODMAP Stacking

Even though 2 slices of sourdough are low FODMAP, eating them with other fructan-containing foods can cause stacking:

• Sourdough + oats = Fructan stacking
• Sourdough + pasta = Fructan stacking

Space out fructan-containing foods throughout the day.

5. Consider Individual Tolerance

Some people with IBS may still react to sourdough even if it’s low FODMAP:

• Gluten sensitivity (separate from FODMAPs)
• General wheat sensitivity
• High fiber content
• Resistant starch

If you consistently have symptoms with certified low FODMAP sourdough, it may not be suitable for you.

6. Try Toasting

Toasted sourdough may be slightly easier to digest than fresh bread. The toasting process changes the starch structure and reduces moisture, which some people find helpful.

7. Store Properly

Keep sourdough at room temperature for 2-3 days or freeze for longer storage. Slice before freezing so you can toast slices directly from frozen.

Low FODMAP Sourdough Recipes

Low FODMAP Avocado Toast

• 2 slices toasted sourdough
• 1/8 avocado, mashed
• Squeeze of lemon or lime
• Salt, pepper, red pepper flakes
• Cherry tomatoes
• Egg on top (optional)

Low FODMAP Sourdough Sandwich

• 2 slices sourdough
• Sliced turkey or chicken
• Lettuce, tomato, cucumber
• Lactose-free cheese
• Mayo or mustard (check ingredients)

Low FODMAP Breakfast Toast

• 2 slices toasted sourdough
• Peanut butter
• Sliced banana (firm, unripe - 1/2 medium max)
• Cinnamon

Low FODMAP French Toast

• 2 slices sourdough
• 2 eggs beaten with lactose-free milk
• Vanilla extract
• Cinnamon
• Fry in butter
• Top with maple syrup (2 tablespoons max) and berries

Sourdough vs. Other Low FODMAP Breads

Sourdough is unique because it’s the only way to make wheat bread low FODMAP through fermentation.

Nutritional Benefits of Sourdough

Beyond being low FODMAP, sourdough offers health benefits:

• Easier to digest - Fermentation pre-digests some of the gluten and starches
• Lower glycemic index - Doesn’t spike blood sugar as much as regular bread
• Better mineral absorption - Fermentation reduces phytic acid, allowing better absorption of iron, zinc, and magnesium
• Probiotic potential - Contains beneficial bacteria (though most are killed during baking)
• Longer shelf life - Natural acids prevent mold growth
• Rich flavor - Complex, tangy taste without artificial ingredients

Scientific Research on Sourdough and FODMAPs

Several studies support sourdough’s low FODMAP status:

• 2018 study in Gastroenterology: Found that bread fermented for 12+ hours had significantly reduced fructan content compared to 2-hour fermentation
• Monash University testing: Confirmed that authentic sourdough bread is low FODMAP at 2-slice servings
• 2016 study: Showed that long fermentation reduces fructans by up to 90%

The research clearly shows that fermentation time is critical - the longer the fermentation, the lower the FODMAP content.

Frequently Asked Questions

Can I eat sourdough during the elimination phase?

Yes, but only authentic sourdough that has been properly fermented for 12+ hours. If you can’t verify the fermentation process, it’s safer to avoid it during strict elimination.

Does freezing sourdough affect FODMAP content?

No, freezing doesn’t change FODMAP levels. Feel free to freeze sourdough for longer storage.

Is sourdough starter high FODMAP?

The starter itself contains active bacteria and yeast, but you eat so little in each slice that it’s negligible. The FODMAPs have been consumed by the bacteria during fermentation.

Can I make sourdough with gluten-free flour?

Yes, you can make gluten-free sourdough with rice flour, buckwheat, or other gluten-free flours. However, without wheat fructans, the main reason for fermentation (FODMAP reduction) is less relevant. It will still have beneficial flavor and texture.

Why do I react to sourdough even though it’s low FODMAP?

Possible reasons:

• The sourdough wasn’t fermented long enough
• You have gluten sensitivity or celiac disease
• You have a wheat allergy (separate from FODMAPs)
• You’re reacting to the fiber content
• FODMAP stacking with other foods
• It’s not actually sourdough (mislabeled product)

Is sourdough better than gluten-free bread?

For people who can tolerate gluten and wheat, sourdough may be preferable because:

• Better taste and texture than many gluten-free breads
• Higher in nutrients
• More natural (fewer additives)
• Easier to find quality artisan versions

However, those with celiac disease or severe gluten sensitivity must choose gluten-free bread.

The Bottom Line

Authentic sourdough bread made with long fermentation (12+ hours) is low FODMAP at 2 slices and can be enjoyed by most people with IBS. The fermentation process breaks down fructans in wheat, making sourdough one of the few wheat-based breads safe on a low FODMAP diet.

The key is finding or making truly authentic sourdough - avoid commercial brands that use shortcuts. Look for artisan bakeries, low FODMAP certified brands, or make your own to ensure proper fermentation.

With the right sourdough, you can enjoy delicious toast, sandwiches, and bread-based meals without triggering IBS symptoms.