Flour is critical in all bread making including sourdough. Yeasted bread can turn flour of lesser quality into something soft and edible. Sourdough needs better quality flour because it’s a living breathing organism, responding to nutrients and proteins in the flours. Being an artisan style bread, rarely baked in a bread tin, it relies on the strength of the gluten bonds to rise without breaking and hold their shape without collapsing. No help from baking tin. The loaves sourdough produces is far superior in both taste and quality.
You will need to use ‘strong’ bread flour. This is a fancy baking term for the flours that are made from hard wheat varieties and have more gluten than other flour types, which gives it elasticity to rise. Strong flour is also called strong because of the hard wheat it comes from and the protein content that creates stronger bonds between the gluten.
Cakes rise and hold together with the use of fat, sugar, and eggs. They are also soft and delicate, designed to crumble. Cake batter is very different to strong and stretchy bread dough! Bread dough is also delicate, but it holds itself together with bonds created by simply adding water.
You can’t use cake flour for bread making or bread flour for cake making. You will ruin your cake or bread.
Remember this one thing
There is a simple way to sort this out. Sourdough culture needs protein (think strength to stretch and lift dough!).
Not all bread flours are created equal for sourdough.
Look for a minimum of 13% protein, or 13g per 100g.
(0.45 ounces per 3.5 ounces)
That’s it. That’s all you need to look for and remember.
You’ll find this information on the back, side or bottom of the flour packet where you find the nutritional information.
Don’t use store-bought bread mixes. They are designed for use with bakers yeast, have seriously low protein content (one of the top brands, Lauke, has 8g). They also contain preservatives that can interfere with your sourdough culture.
You can, of course, make and use your own Sourdough bread mix! That’s the exception.