Flour Types and When to Use Them
When I first started researching sourdough, I thought flour was just flour.
I was wrong.
The type of flour you use affects everything. Structure, texture, hydration, flavor. And understanding the differences between all-purpose, bread flour, whole wheat, rye, and 00 flour changed how I approached baking.
Here's what I've learned.
Why Flour Type Matters
Flour isn't all the same because the protein content varies.
And protein matters because it creates gluten. Gluten is what gives bread structure, chew, and the ability to hold its shape as it rises.
More protein = more gluten development = stronger structure.
Less protein = softer, more tender crumb.
That's why you wouldn't use bread flour for cookies (too much structure, too chewy) and you wouldn't use cake flour for sourdough (not enough structure to support a loaf).
Understanding protein content helps you choose the right flour for what you're making.
Bread Flour: The Workhorse
Protein content: 12-14%
Bread flour has higher protein than all-purpose, which means it develops more gluten. That's what you want for sourdough. Strong structure that can support a long fermentation and a good rise.
It also absorbs more water than all-purpose flour, which means you can work with higher hydration doughs without them becoming too slack.
I use bread flour for my sourdough loaves. It gives me the structure and chew I want, and it handles the long fermentation well.
All-Purpose Flour: The Versatile Option
Protein content: 10-12%
All-purpose flour is exactly what it sounds like. It works for most things.
It has less protein than bread flour, which means a softer, more tender crumb. That makes it perfect for cookies, muffins, biscuits, and some breads.
You can absolutely make sourdough with all-purpose flour. It'll be a little softer, a little less chewy. Some people prefer that.
I use all-purpose for my cookies and some of my sweeter baked goods. It gives me the texture I want without being too dense or chewy.
Whole Wheat Flour: Adding Nutrition Without Overdoing It
Protein content: Similar to bread flour (12-14%), but it behaves differently.
Whole wheat flour contains the bran and germ from the wheat kernel, not just the endosperm. That means more fiber, more nutrients, more flavor.
But here's the catch. The bran cuts through gluten strands. That's why 100% whole wheat bread can feel dense and heavy. The bran is literally slicing up the structure you're trying to build.
Whole wheat also absorbs more water than white flour. If you're substituting whole wheat into a recipe, you'll need to adjust your hydration.
I use about 15-20% whole wheat (King Arthur calls it Golden Wheat) in my baked goods. That gives me the nutritional boost and deeper flavor without making things too dense or affecting the texture people expect.
It's a balance. A little whole wheat goes a long way.
Rye Flour: The Unique One
Protein content: Rye has protein, but it doesn't form gluten the same way wheat does.
Rye contains very little gluten-forming protein. Instead, it produces a sticky, dense dough that behaves completely differently from wheat-based doughs.
That's why most rye breads are a blend of rye and wheat flour. You need the wheat to provide structure.
Rye also absorbs a lot of water. Way more than you'd expect. And it ferments faster than wheat, so timing is different.
I use rye specifically for my rye sourdough loaf. It has a distinctive earthy flavor that I love, but it's not a flour I'd use for anything else.
Rye is special-purpose. And if you've never worked with it, start with a small percentage mixed with bread flour until you get a feel for how it behaves.
00 Flour: For Pizza and Pasta
Protein content: 11-12% (similar to all-purpose, but finely milled)
00 flour is an Italian flour that's milled incredibly fine. Almost powdery.
The "00" refers to how finely it's ground, not the protein content. It can have varying protein levels depending on the brand, but it's typically around 11-12%.
What makes 00 flour special is the texture. That fine grind creates a silky, extensible dough that's perfect for pizza and pasta. It stretches easily without tearing.
I don't use 00 flour for my sourdough loaves. But if you're making pizza or fresh pasta, it's worth trying. The texture is noticeably different from all-purpose or bread flour.
Bleached vs. Unbleached: What's the Difference?
Bleached flour has been chemically treated (usually with benzoyl peroxide or chlorine gas) to age it artificially and make it whiter.
Unbleached flour ages naturally. It's slightly off-white or cream-colored instead of pure white.
The bleaching process strips some nutrients and changes the flour's protein structure slightly. It also leaves behind trace chemicals.
I only use unbleached flour. I don't want bleach or chemical residue in my bread. And honestly, the natural aging process produces better flavor.
If a recipe calls for bleached flour and you're using unbleached, it'll work fine. The difference is minimal in most cases.
Flour Freshness: Does It Matter?
Yes.
Flour doesn't go bad quickly, but it does lose freshness. Whole wheat and rye flour especially can go rancid over time because they contain oils from the germ.
I try to use flour within a few months of opening it. I store it in airtight containers in a cool, dry place.
If your flour smells off or tastes bitter, toss it. Fresh flour makes better bread.
Mixing Flours: When and Why
I mix flours all the time.
Sometimes I'll use a blend of all-purpose and bread flour to get a texture that's in between. Sometimes I'll add 15-20% whole wheat to white flour for nutrition and flavor.
Mixing flours lets you control the final result more precisely than using just one type.
Just remember, if you're adding whole wheat or rye, you'll need to adjust your hydration. Those flours absorb more water.
If You're Just Starting: Which Flour Should You Buy?
If you're brand new to sourdough and you're buying your first bag of flour, get unbleached bread flour.
It'll give you the structure you need for a good loaf. It's forgiving. It works.
Once you're comfortable with bread flour, experiment. Try adding some whole wheat. Try all-purpose for a softer crumb. Try rye if you want to explore different flavors.
But start with bread flour. It's the foundation.
Why I Use King Arthur
I prefer King Arthur flour because it's consistent.
The protein content is reliable. The quality is good. And they don't bleach their flour.
But honestly, I also love their company philosophy. They're employee-owned, which means the people making the flour have a stake in its quality. They're not just producing a product for shareholders. They're invested in making it right.
King Arthur is also deeply committed to baking education. They offer classes, publish recipes, create resources for home bakers. They want people to succeed in their kitchens, not just buy their products.
That matters to me. I'm supporting a company that aligns with my values. Quality ingredients, education, and treating employees well.
You don't have to use King Arthur. But find a brand you trust and stick with it. Consistency in your ingredients makes it easier to get consistent results.
What I Wish I'd Known Sooner
Flour type affects everything.
When I first started, I didn't realize how much difference protein content made. I didn't know that whole wheat absorbs more water. I didn't know rye behaves completely differently from wheat.
I learned by reading, experimenting, and paying attention to how different flours performed.
Now I choose flour intentionally based on what I'm making. And that's made me a better baker.
What flour do you use most? Have you experimented with different types?
— Courtenay 💙
