The majority of the flour we consume is made from a single species of wheat: Triticum aestivum, also called “bread wheat” or “common wheat”. It’s a species that’s been cultivated for hundreds of years, and like all crops that have been widely grown over long periods, different forms of it have evolved and/or been created over time. Nowadays we grow many different types of T. aestivum, all with different properties.
In America our most common wheats are Hard Red Spring Wheat, Hard Red Winter Wheat, Soft Red Wheat, Hard White Wheat and Soft White Wheat. All are used, sometimes alone but usually in combination, to make the flours we find on grocery store shelves. Of the varieties, the hard wheats make up about three quarters of the annual harvest in the US, soft wheats about 20%, and oddballs like club wheat and durum (both of which are different species of wheat, and are used for cake flour and pasta respectively) make up the rest.
Here in the States we’re used to talking about flours in terms of how much gluten (protein) they contain. Know the gluten percentage of a given flour and you know a fair amount about it: how hard or soft the wheat that it came from, how well it will perform in a cake or a bread, how chewy or tender your finished product will be, and so on.
Europeans gemerally do not talk this way. When they talk flour, they speak of “ash content“, which is also a highly descriptive measure, just very different from gluten content. And while we’re on the subject of Europe, I should point out that European gluten is very different from North American gluten. While ours is stretchy and elastic, theirs is firm and plastic, meaning it doesn’t “snap back” like ours does when it’s stretched. That’s nice, but it’s an advantage that comes with some disadvantages as well. If you’ve ever eaten a French blueberry muffin, you know what I’m talking about.
“Extraction rate” sounds like a technical term. Which it is. Though that’s not to say that home bakers like you and I can’t understand it and use it. Particularly if you like to bake bread, an extraction rate can give you a good deal of information about a flour, as well as several clues about how it will behave.
So, to business. When someone uses an extraction rate in a sentence, say, “this is a 65% extraction flour”, at least two important types of information are being conveyed. The first is the region of the wheat berry where the flour has been taken from. The second is the composition of the flour, i.e., how much of the softer inner endosperm, harder outer endosperm, and even bran and germ the flour contains. And when you know all that, you also have a sense for how much gluten (protein) the flour contains, even the grind of it. It’s one pretty darn info-packed number.
This applies only to North America I need to emphasize, and really most of this information isn’t terribly relevant to home bakers, but you know I like to be thorough. So here goes.
You’ll perhaps remember from the below post the “fairly coarse, fairly dark” flour you get when you grind the whole endosperm of a wheat berry with the bran and germ removed? Well that’s what we in the States call “straight” flour. We generally don’t bake with it, we sift it, though the French frequently use it for bread flour. Just another reason why replicating French breads in the US is difficult.
This is one of those terms that’s not absolutely crucial to understanding bread flours, but it’s a nice-to-know if we’re getting more heavily into this subject. A flour’s falling number is simply an indicator of its starch quality. Which is to say, it tells you how intact the flour’s long, whispy starch molecules are, because […]
Bleaching gets a very bad rap these days. It’s frequently portrayed as a trivial cosmetic process that comes at the steep cost of adding chemicals — chemicals! — to our food. More than that it could be racist. But in fact bleaching is not primarily about a flour’s whiteness, it’s about a flour’s performance.
But first what exactly is “bleaching”? In general, bleaching means exposing flour to a compound like chlorine gas, ascorbic acid (vitamin C) or perhaps an enzyme like lipoxygenase (derived from fava or soy beans). These agents leave no residues or residual flavors, nor do they, contrary to popular myth, diminish the flour’s nutritional value.