Reader Jim C. asks:
OK, uncle Joe, how about a nod towards us bread history buffs? I’m guessing that in earlier centuries [wheat bran, germ and endosperm] WAS crushed together and that separating them out was a relatively recent development? For people who want to make bread “just like” those of earlier eras (“bread reenactors”, I call them), this sort of nuance matters
I wish I knew more about the history of milling to be able to comment on this with more authority. What I do know is that prior to about 1735, all flour was ground the old-fashioned way, by crushing whole wheat berries between rotating millstones. Then, flour quality — assuming it hadn’t been “cut” with additives like chalk or bone meal — was mainly a matter of sifting (or “bolting” as it was known in the trade). Higher quality flour was the stuff that managed to pass through several layers of cloth. That smaller particle size would have yielded lighter-textured, higher-rising breads. My guess is that those sifted flours would have been whiter as well, since flakes of bran would likely have been harder to pass through the weave of a bolting cloth.
Around 1785 steel roller mechanisms started to appear, the precursors to today’s milling technology. Rollers are not only a more efficient way to pulverize grain, they’re also capable of pinching the germ off the end of a wheat berry. I honestly don’t know to what extent the operators of steel roller mills separated germ and bran out, at least at first. However I do know that from there on out millers raced to create flours of higher and higher “extraction”, meaning that they were in competition to pull more and more pure endosperm out of the wheat berry, leaving the rest behind.
I’ve never found book that explains much about modern milling techniques. Truth be told, milling is a rather secretive business. Granted, mills tend to be more tight-lipped about their wheat blends than their equipment per se, but I’ve never met an employee of a major mill that’s been particularly chatty about operations. If anyone out there can recommend any good books on the subject, I’d be interested.
UPDATE: I just found this in the Encyclopedia of American Food and Drink:
The production of wheat flour picked up after the invention in 1834 of the Swiss steel roller that ground the meal very finely, a process vastly improved in 1865 by French-American Edmund LeCroix, by separating bran from granual middlings with a middling purifier and fan-driven air currents to clean the wheat as it moved through the mill. The first all-roller flour mill was displayed in the United States at the 1876 Philadelphia Centennial Exposition.