Bread flours are mainly milled from hard wheat, which gives them a high protein content which produces a high level of gluten for raising bread.
“Bread flour is made from hard wheat and the higher gluten content creates volume and a chewier product desirable for loaves of breads and pizza crusts. Bread flour is not recommended for cakes and cookies due to the higher gluten content, because the baked goods will be tough. Bread flour may be more expensive than regular or all-purpose flour. If you have been satisfied with the taste and texture of your bread when using all‑purpose flour, there may not be reason to change.” Rellinger, Diane. Be a knowledgeable baker when using cake, pastry or bread flour. Michigan State University Extension. 18 May 2012. Accessed January 2021 at https://www.canr.msu.edu/news/be_a_knowledgeable_baker_when_using_cake_pastry_or_bread_flour
The best bread flour is ground from Canadian wheat. This bread flour will have an average protein content of 14%, while European flours weigh in far behind with an average of only about 9 %. American bread flour will have a protein content of 12 to 13%.
In the UK, you can purchase Canadian flours at Waitrose; and Sainsbury’s strong white bread flour is said to have a lot of Canadian wheat in it.
|Canadian Bread Flour||13.6 to 15.6 % (db)||0.56 to 0.63% (db)|
In the chart above, (db) equals dry basis. Europe uses dry basis measuring, while North America tends to measure at 14% humidity. That being said, North American numbers will often give dry basis equivalents, so where possible those are used on this site in order to be comparing apples with apples, as it were.
If you have gluten flour (aka vital wheat gluten) to hand you can follow this advice from Apollonia Poilâne of Poilâne Bakery in Paris:
- 1 cup (130 g) all-purpose or plain flour
- 1 teaspoon (2.5 g) gluten flour
Measure the all-purpose flour. Remove from it 1 teaspoon of flour. Add the teaspoon of gluten flour, and stir in.  Apollonia Poilâne. How to Make Bread Flour Substitute at Home. 16 December 2020. Accessed March 2022 at https://www.masterclass.com/articles/how-to-make-bread-flour-substitute You can make this in large batches and store.
(Though if you have to go out anyway to buy the gluten flour, you might just as well buy bread flour while you are at it.)
|↑1||Rellinger, Diane. Be a knowledgeable baker when using cake, pastry or bread flour. Michigan State University Extension. 18 May 2012. Accessed January 2021 at https://www.canr.msu.edu/news/be_a_knowledgeable_baker_when_using_cake_pastry_or_bread_flour|
|↑2||Apollonia Poilâne. How to Make Bread Flour Substitute at Home. 16 December 2020. Accessed March 2022 at https://www.masterclass.com/articles/how-to-make-bread-flour-substitute|