Best Gluten-Free Flour Blends for Sourdough
One of the biggest challenges in gluten-free sourdough baking is choosing the right flour — or more accurately, the right combination of flours. Unlike wheat sourdough, where a single bag of bread flour can carry you from start to finish, gluten-free sourdough almost always relies on a blend of two or more flours working together.
Get the blend right, and you end up with bread that has real flavour, a decent crumb, and a crust that actually crisps up. Get it wrong, and you're dealing with a dense, gummy loaf that falls apart the moment you slice it.
This guide covers the most useful gluten-free flours for sourdough, what each one contributes, and how to build a blend that works. Whether you're baking for coeliac disease, gluten sensitivity, or simply curious about alternative grains, this is where to start.
Why Gluten-Free Sourdough Needs a Flour Blend
Wheat flour works in bread because of gluten — the protein network that traps fermentation gases, holds the dough together, and gives bread its chewy, elastic structure. Gluten-free flours don't have this. No single gluten-free flour can fully replicate what gluten does on its own.
That's why blending matters. Each flour contributes something different:
- Structure — Some flours provide starch that sets during baking, giving the loaf its shape
- Flavour — Whole grain flours like buckwheat and teff add depth and complexity
- Binding — Certain flours, especially those higher in fibre, help hold the crumb together
- Fermentation food — Wild yeast and bacteria in your starter need fermentable sugars. Some flours provide more than others
A good blend covers all four bases. It also tends to produce a loaf that behaves more predictably — better rise, better crumb texture, and less of that tell-tale gumminess that plagues single-flour GF breads.
To understand more about the fermentation side of things, see our guide to The Complete Guide to Gluten-Free Sourdough Bread.
The Core Gluten-Free Flours for Sourdough
Rice Flour
Rice flour is the workhorse of gluten-free baking. It's mild in flavour, widely available, and ferments reliably — making it a solid base for most GF sourdough blends.
There are two main types:
White rice flour is fine-milled from polished rice. It produces a light crumb and has a neutral taste, which makes it useful as a high-proportion base flour (typically 40–60% of a blend). The downside is that it offers little in the way of flavour or nutrition on its own.
Brown rice flour is milled from whole-grain rice, so it retains the bran and germ. It has more flavour than white rice flour, a slightly nuttier quality, and a higher nutritional profile. It also tends to ferment a little more actively, which suits sourdough well. The tradeoff is a slightly denser, grainier texture in the final loaf.
Many bakers use a combination of both — white for lightness, brown for flavour — within the rice flour portion of their blend.
According to the Coeliac UK flour guide, rice flour is one of the most widely tolerated and accessible options for people following a gluten-free diet.
Best used as: Base flour at 40–60% of total blend
Buckwheat Flour
Despite the name, buckwheat has nothing to do with wheat. It's a seed — botanically related to rhubarb — and it's naturally gluten-free. It's also one of the most valuable flours you can add to a GF sourdough blend.
Buckwheat is rich in flavour. It brings an earthy, slightly bitter depth that makes gluten-free sourdough taste like actual bread rather than a pale substitute. It ferments exceptionally well because it contains sugars that wild yeast and lactic acid bacteria readily consume. This makes it useful not just in the dough but as a base for building a gluten-free sourdough starter.
Buckwheat also has a decent protein content (around 13%) and contains a range of B vitamins, magnesium, and antioxidants. Research published in the journal Nutrients has highlighted buckwheat's strong fermentation characteristics and its positive contribution to the nutritional profile of sourdough bread.
The flavour is strong, so use it in moderation. At 20–25% of a blend, it adds character without overpowering. Push it higher and the bitterness can become dominant.
Best used as: Flavour and fermentation booster at 15–25% of total blend
Sorghum Flour
Sorghum is a whole grain cereal that produces a flour with a mild, slightly sweet flavour. It's one of the most "wheat-like" gluten-free flours available, which makes it a useful addition to blends where you want to soften the more assertive flavours of buckwheat or teff.
Sorghum flour has a higher protein content than rice flour — typically around 10–11% — and it contributes to a softer crumb and better moisture retention. Bread made with sorghum tends to stay fresher for longer than rice-based loaves.
It ferments reasonably well, though not as vigorously as buckwheat. It works best when paired with a more active fermentation partner rather than used as the sole flour in a blend.
The Whole Grains Council notes that sorghum is an ancient grain with a long history of use across Africa and Asia, and one of the most drought-tolerant crops grown today.
Best used as: Texture softener and protein contributor at 20–30% of total blend
Teff Flour
Teff is a tiny ancient grain from Ethiopia and Eritrea. It's the base of injera — the traditional fermented flatbread that's central to Ethiopian cuisine — which tells you something important: teff was made for fermentation.
In sourdough, teff adds a rich, almost chocolatey depth of flavour. It's darker in colour than most gluten-free flours, so blends that include teff will produce a darker loaf — more rustic-looking, less sandwich-bread-pale.
Teff is also one of the most nutritious grains available. It's high in iron, calcium, and resistant starch, which feeds the beneficial bacteria in your starter. A study in the LWT Food Science and Technology journal found that teff-based fermented products showed strong probiotic activity and a favourable amino acid profile.
Because the flavour is intense, teff is typically used in smaller amounts. At 10–15% of a blend, it contributes colour and complexity. Used at higher amounts, it can make the loaf quite dense and bitter.
Best used as: Flavour and nutrition booster at 10–15% of total blend
Tapioca Starch (Tapioca Flour)
Tapioca starch is derived from cassava root. Unlike the whole-grain flours above, it's almost pure starch with very little protein, fibre, or flavour. So why include it?
Because it solves a practical problem. Gluten-free doughs often bake up too crumbly or too dense. Tapioca starch adds chew and elasticity to the final loaf — qualities that are normally provided by gluten. It also helps the crust crisp up during baking.
Tapioca acts as a binder, helping to hold the loaf together in the absence of gluten. It's light and neutral, so it doesn't compete with the flavour of the other flours in a blend.
Use too much and the bread becomes gummy — especially in the crumb. Keep tapioca to 10–20% of a blend and it does its job without causing problems.
Best used as: Texture improver and binder at 10–20% of total blend
Oat Flour (Certified Gluten-Free)
Oats are naturally gluten-free, but they're often processed in facilities that also handle wheat, barley, and rye — which means cross-contamination is a real risk. For people with coeliac disease, only certified gluten-free oat flour is safe to use.
For those who can tolerate oats, GF oat flour is a genuinely useful addition to a sourdough blend. It has a mild, slightly sweet flavour, a soft texture, and it ferments well. It contributes to a tender crumb and a more open texture than dense whole-grain flours.
It's worth noting that some people with coeliac disease react to a protein in oats called avenin, even in certified GF varieties. If you're baking for someone with coeliac disease, it's worth checking whether they tolerate oats before including them.
Best used as: Texture softener at 15–25% of total blend (certified GF only)
How to Build a Gluten-Free Sourdough Flour Blend
A well-designed GF sourdough blend typically follows a simple structure:
Base flour (40–60%): White rice flour, brown rice flour, or a combination of both. This provides the neutral starchy backbone of the blend.
Whole grain flour (20–30%): Buckwheat, sorghum, teff, or oat flour. This is where flavour and nutrition come in. Most bakers use one or two whole grain flours at this level.
Starch (10–20%): Tapioca starch, potato starch, or arrowroot. This improves texture and adds the elasticity that gluten normally provides.
Three Starting Point Blends
These blends are a useful starting point. Adjust ratios based on taste and how your starter performs.
Blend 1 — Everyday GF Sourdough
Good for: beginners, mild flavour, reliable rise
| Flour | Percentage |
|---|---|
| White rice flour | 40% |
| Brown rice flour | 20% |
| Sorghum flour | 20% |
| Tapioca starch | 20% |
Blend 2 — Rustic Whole Grain
Good for: flavour-forward baking, more nutritious loaves
| Flour | Percentage |
|---|---|
| Brown rice flour | 40% |
| Buckwheat flour | 25% |
| Sorghum flour | 20% |
| Tapioca starch | 15% |
Blend 3 — Heritage Grain
Good for: deep flavour, darker loaves, adventurous bakers
| Flour | Percentage |
|---|---|
| Brown rice flour | 35% |
| Buckwheat flour | 25% |
| Teff flour | 15% |
| Tapioca starch | 15% |
| White rice flour | 10% |
Does Hydration Change with Different Flours?
Yes — significantly. Gluten-free flours absorb water differently, and whole grain flours generally absorb more than refined ones. Teff and buckwheat, in particular, can soak up a lot of water.
As a general rule, GF sourdough doughs are much wetter than wheat sourdough doughs. Rather than a firm, shapeable dough, most GF sourdough looks more like a thick batter — this is normal. You'll typically bake it in a loaf tin rather than free-form.
If you're switching flour blends, expect to adjust your water content. Start at the lower end and add water slowly until you reach the right consistency: thick enough to hold its shape in a tin, but fluid enough to spread and level out on its own.
For a full breakdown of hydration in sourdough baking, see our guide on Understanding Hydration in Sourdough.
Do You Need a Binder?
Gluten-free bakers often add a binder to their dough to replace some of the structural work that gluten normally does. The two most common options are:
Psyllium husk powder — This is the most effective binder for GF sourdough. It absorbs water and forms a gel that mimics some of gluten's elasticity. Use around 1–2 tablespoons per 500g of flour. It's the reason many modern GF sourdough recipes can be shaped and scored rather than just poured into a tin.
Flaxseed (ground) — Ground flaxseed mixed with water forms a gel similar to psyllium husk, though with a slightly nuttier flavour. It works well in denser, whole-grain-style loaves.
Xanthan gum — An older option that's still used in many commercial GF products. It can produce a slightly gummy texture if overused. Psyllium husk tends to produce better results in sourdough specifically.
Common Flour Blend Mistakes
Using a single flour. A single GF flour rarely produces a good sourdough loaf. Even if the rise is decent, the flavour and texture will be flat. Blending is worth the extra effort.
Too much tapioca starch. Tapioca improves texture, but more than 20% creates a gummy, undercooked-feeling crumb — especially noticeable near the centre of the loaf.
Ignoring fermentation behaviour. Not all GF flours ferment equally well. Teff and buckwheat are very active; rice flour less so. If your blend is heavy on rice flour, your starter may need to be particularly strong before baking. See our guide on How to Make a Gluten-Free Sourdough Starter for more on this.
Buying a commercial GF baking mix. Pre-made GF flour mixes are formulated for quick breads and cakes — they're not designed for the long fermentation times that sourdough requires. They often contain added binders and leavening agents that interfere with the sourdough process.
Troubleshooting Your GF Flour Blend
If your gluten-free sourdough is giving you trouble, the flour blend may not be the only culprit — but it's worth checking. Our Gluten-Free Sourdough Troubleshooting guide covers the most common problems including gummy crumb, flat loaves, and poor oven spring, with specific fixes for each.
Ready to Bake Gluten-Free Sourdough With an Expert?
Getting flour blends right through trial and error takes time. In our Gluten-Free Sourdough Workshop, we've already done the testing — so you spend three hours learning hands-on technique with a blend that's been refined to work well consistently. You'll leave with a loaf you made yourself, the recipe and ratios we use, and a clear understanding of why each flour is in the mix.
Not sure which workshop is right for you? Our Classic vs Rye vs Gluten-Free comparison guide can help you decide.
