Saturday, February 1, 2014

Picking the Right Flour for the Job

In most grocery stores you'll see many types of white wheat flours: all-purpose, cake,  bread, self-rising (if you are in the South), and sometimes pastry. Less common are the whole wheat varieties -- you can usually find whole wheat all-purpose flour easily, but whole wheat pastry flour and whole wheat bread flour are harder to come by. When I was growing up, we usually had all-purpose white flour, self-rising white flour, and cake flour on hand. The cake flour was always Swans Down, and the others were nearly always White Lily. I never heard of bread flour or pastry flour until I was grown! So ... what distinguishes these types of flours, and why should you care?

Missing: The bag of unbleached all-purpose white flour I have; it was way in the back of the
flour/cornmeal/sugar cabinet. Yes, I have an entire 2-door cabinet devoted to baking supplies.

In this post, we'll consider white flours; in a later post, we'll look at whole wheat. In all cases, though, the main difference is the amount of protein in the flour. The amount of protein dictates, in part, how much gluten can develop in a dough. Gluten provides strength and structure. In yeast breads, gluten is vital to getting a good rise and having a light end product. In some baked goods, however, a lot of gluten is more of a problem than a help. In quick breads, you don't want a lot. In cakes or pastry (such as pie crust or even biscuits) you want even less; otherwise the end product can be tough.

All-purpose flour, naturally, is the most common. It is in the middle of the pack when it comes to protein content. Many many recipes for all kinds of baked goods specify all-purpose (AP) flour, or just say "flour." It's perfectly suitable for many types of baked goods. In some cases, though, you will get better results if you match the baked good with the right flour.

Here's where it gets complicated.

First, brands vary in the protein content for a given type of flour. This is due in part to the variety of wheat used and even the season in which it was grown. So, you can't count on all AP flours, for example, to be exactly the same.

Second, the nutrition information on packages of flour isn't necessarily helpful. They give the info for 1/4 cup of flour. Since the measurements displayed for protein are in whole numbers, there's some rounding going on. Most AP flours I've seen say that 1/4 cup contains 4 grams of protein. The truth is that means it could have anywhere from, say, 3.5g to 4.4g. If I'm using a flour with 4.4g, it might make decent yeast bread but not-so-great biscuits or pie crust. This lack of precise information makes comparing types and brands difficult.

Professional bakers think about flour in terms of the percent of total weight represented by protein. This information won't be on the bags of flour, but knowing what the ranges are for the different types gives you an idea of the relationships. So, if a baker was looking for a typical American AP flour, they would usually look for something that is between 10% and 12% protein.

The following information comes from the fabulous book CookWise: The Hows & Whys of Successful Cooking, The Secrets of Cooking Revealed by Shirley O. Corriher, and from Baking Science: Comparing Flours.

Type Representative Brands Protein Content
Cake flours Swans Down, Softasilk 7.5 to 8.5%
Southern bleached all-purpose White Lily, Martha White, Gladiola, Red Band 7.5 to 9.5%
Pastry flour various 8% to 9%
National bleached all-purpose Gold Medal, Pillsbury 10 to 12%
Northern bleached all-purpose Robin Hood, Hecker’s 11 to 12%
Northern unbleached all-purpose King Arthur 11.7%
Bread Flour various 11.5 to 12.5%

My mom was a champion biscuit- and cake-maker. If a cake recipe called for cake flour, she used it, but otherwise she used the White Lily AP for everything. The truth is, though, that it probably has around the same protein content as the Swans Down. The low protein content of Southern brand flours is actually in the same general range as pastry flour, as well. If you use a Southern brand of AP flour -- one made from soft winter wheat -- it's important to keep this in mind. While some national / Northern AP flours would be OK for yeast breads, for example, I wouldn't want to try baking one with White Lily or Martha White. Similarly, I don't feel the need to use pastry flour instead of White Lily AP for biscuits, pie crust, or other pastry. 

Next time, I'll delve into whole wheat flours, and why it can be so tough to make a decent loaf of 100% whole wheat yeast bread. Finally, I'll share an awesome 100% whole wheat bread that overcomes these problems! Until then, here's a preview.

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