Ash Wednesday

One of the things I have struggled with while working on Breaducation is the choice of flours to use in my doughs. The book is meant to be both an introduction to bread baking of all kinds and an overview of how I make breads at home myself. As a result, I've had to strike a balance between what I'd do and use, and what is easily done or accessible to anyone. For that reason, I have chosen to focus on flours that can be purchased at supermarkets rather than those from small millers, despite using the latter all the time myself.

When it comes to many things like enriched breads and many flatbreads, the choice was easy: a refined flour with moderate protein content. For these products, I use King Arthur all-purpose or an equivalent, with a protein content of 11–12%. I used to refer to these as "high-protein all-purpose flours," but was never happy with the term, since they are only "high-protein" in relation to other AP flours, and true high-protein flours are a different beast altogether, with levels of 14% and higher. In the book, I call it soft bread flour, because it is soft, but still strong enough for breads. It's almost never labeled as a bread flour, despite being an excellent one in many cases.

For the few instances that I find a recipe needs a bit more strength, either because the product demands it (bagels, for example), or to offset the inclusion of something that compromises crumb structure, like a porridge or a high percentage of whole-grain flour or fat, I call for bread flour, i.e., those flours labeled as bread flour, with 12–13% protein.

But when it comes to crusty breads, my personal preference much of the time is to use high-extraction flours, those that have been stone-milled and then sifted to remove larger particles of bran. Because some of the bran and all of the germ is milled as finely as the endosperm, high-extraction flours, despite being close in extraction rate to that of roller-milled white flours, have character—not only do they have flavor and color, but each one is unique to the grain from which it was milled. And because they are sifted, they perform much like refined white flours do, with a few adjustments to hydration and technique. But there are two problems with high-extraction flours, both of which made me wary of calling for them in Breaducation.

One: each one is unique, whether because of the grain in question or the miller who milled it (even the same grain from the same farmer might change from year to year). High-extraction flours require finesse to make the most of—each must be approached on its own terms, and some level of experimentation is necessary when working with a novel one. And two: they aren't available in supermarkets.

At first, this seemed to mean that I'd have to forgo calling for high-extraction flours in the book, reserving discussion of them to general recommendations on how to swap one in for a refined flour by adjusting hydration up to accommodate their higher thirstiness. But then I stumbled upon a novel way of thinking about flours that meant I could call for either supermarket and high-extraction flours in the same formula and have both work more-or-less identically.

Extraction rate, ash content, and type classifications

The extraction rate of a flour is simply the percentage of the original grain that remains in it after milling and processing. Stone-ground whole-wheat is by definition “100%-extraction,” because it contains all of the wheat berry—bran, germ, and endosperm; roller-milled white flours, which are nearly pure endosperm, are about 72% extraction. High-extraction flours typically vary from 75–85% extraction, though my preference is for those that are closer to 85%.

Another way to describe a flour’s extraction rate is by its ash content, which is determined by incinerating a small amount of flour and measuring the weight of what is left behind. When a flour is combusted, most of its contents are released as heat, carbon dioxide, and water; all that remains are the minerals it contained. Since most of the minerals in a grain are located in the bran and germ, more ash is produced in whole-grain and high-extraction flours than in white flours.

In Europe, flours are classified by type, a number that corresponds to its ash content. The refined bread flours we use in baking—including my soft bread flour—are Type 55 flours, with an ash content between 0.5 and 0.6%. Type 65 flour is similar to Type 55, but with slightly more bran and germ, and often a slightly higher protein content; it has an ash content of about 0.65%. The sorts of high-extraction flours I like are Type 80 flours, with an ash content around 0.8%. And whole-wheat flours are Type 150, with an ash content of about 1.45%. (Flour types are often abbreviated—for example, Type 55 is often referred to as “T55.")

One day I was thinking about all this and had a revelation: Because the ash content of flours are known quantities, you should be able to blend a flour of a lower ash content (a refined flour) and one of a higher one (whole-wheat flour) to precisely mimic one with an ash content between the two. I'm sure there's a math person who could easily write a formula to figure this sort of thing out directly, but not me. So I just did it the long way by blending two flours in varying ratios on paper, until I landed on a combination that was in the ballpark of a Type 80 flour:

refined soft bread/bread flour: 0.55% ash x 0.7 = 0.385%

whole-wheat flour: 1.45% ash x 0.3 = 0.435%

0.385 + 0.435 = 0.82% ash

Once I figured this out, I put the theory to the test: I made two sourdoughs, one using my favorite Type 80 flour, and another with a 70:30 blend of soft bread and whole-wheat flour, and got these:

The doughs had an identical hydration and behaved and felt similarly, from mix to bake. Both the doughs and the crumb (neither of which I have pictures of, sorry) looked slightly different, because the blended one contained flecks of unsifted bran that the high-extraction one lacked, but otherwise it was hard to tell them apart. (They were certainly no different than doughs made from two separate high-extraction flours might be.)

Problem solved! Now in the book those recipes in which I'd normally use high-extraction flour will instead contain a 70:30 mix of bread flour and whole-wheat; the headnote will mention that T80 flour can be used in place of both. I'm still hoping that readers will eventually make their way to working with high-extraction flours, but at least now I know they can prepare themselves to by practicing on flours that are easily accessed.

Type 65 flour

Type 65 flour not sold here in the U.S., and is rarely mentioned in American baking books, but in France, it is used by bakers that want to add a little more color and character to their refined-flour loaves. For fun, I did the math on T65 too, and it worked out to a 9:1 ratio of T55 and whole-wheat, or a 92:8 ratio of T55 and whole-rye. (The ash content of whole-rye is higher than that of whole-wheat—around 1.7%. I wouldn't use it to make a high-extraction flour substitute, however, because the amount needed would reduce the amount of gluten-forming proteins in the dough excessively.). You can also mimic it by using a 60:40 blend of T55 and T80 high-extraction flour.

While few American bread bakers call for T65 flour, many—especially those who trained under French bakers—add small amounts—5-10%—of whole-wheat or rye flour to their white-flour formulas, and this explains why.

—Andrew