Reference:

On Food and Cooking, pages 273-284.

The origin of bread.
The nature of leavening.

yeast
baking powders

Brown vs white bread.

Bread is a remarkable product in that it allows the consumption of cereal grain products to be pleasurable. In the absence of bread, grains could be boiled and eaten whole, as rice, ground up and mixed with water to form a paste (gruel) which is boiled and consumed, or the paste could be parched on hot stones. The paste could be set aside for a few days to ferment, and "raise", producing flat breads.

Once it was observed that breads could be made to raise (because of the gluten content of wheat), bread became the cereal grain product of choice amongst any culture with access to wheat. Many Biblical references attest to the significance of bread. Even the most important of sacraments, like communion, refers to bread; "the bread of life". Old testament references to bread go back to Moses, and the preparation of unleavened bread, a tradition still honored at passover.

In western European cultures, as in ancient cultures of the middle east, the white bread was considered the superior form of bread. White bread is made from the refined flour made solely from the germ (the endosperm) with the bran removed. Darker whole grain breads and products from grains other than wheat were fed to lower classes.

Bread has had a great influence on our english language. English is derived from the germanic Anglo-Saxon language, where hlaford meant "loaf ward", the one who distributes bread, and from hlaford we get the word "lord". The word "lady" is from the Germanic "hlaefdige", meaning kneader; she produces what the husband distributes.

Origins of Bread

The husk of wild wheat does not separate easily from the grain. As such, it is likely that wheat was parched to remove the husk. This heating of the wheat grain destroyed the proteins that formed the gluten. The resulting gruel would not raise. It is thus likely that any parched wheat gruel would have reacted like corn or rice gruel upon parching, producing a product like tortillas or rice "pancakes".

The domesticated wheat varieties that we have knowledge of are those for which the husk separates easily from the grain, without parching. Any gruel made from such a wheat grain would raise (assuming that it was infected with the appropriate yeast species) to produce a tastier bread. From this point, refinements and developments leading to the kind of bread we now consume would be inevitable.

Wheat production for the making of bread lead to developments of animal, wind and water powered grinding mills, where the wheat grains would be ground between two large stones. Fermentation is basic to bread, and the yeast required would have originally been the result of chance infections. Old dough was the primary source of yeast, and is still the source of yeast in fancy bakeries in places like Paris and San Francisco. Also , we saw the development of the oven as a means for baking the bread.

Traditionally, in rural areas in particular, bread was baked in the home. As western society became more urbanized, however, more and more bread was baked outside the home. This was challenged on moral grounds as the phenomenon developed, with the belief that women who could not stay home and bake their own bread were morally inferior. Added to this was the fact that the consumer lost control of the contents of the bread, with commercial bakeries adding substances like chalk and alum to bread as whiteners. Thus commercial bread was seen by some as "corrupt" in contrast with the "purity"
of home baked bread. In 1900, 95% of all flour produced was sold to families. By 1970, this number was 15%. It takes too much time to bake bread. Today however, with bread machines, all one has to do is dump in the ingredients and turn on the machine.

Leavening

While yeast was the traditional leavening, derived from old dough or from beer or wine, it was not known precisely what the leavening agent was until Louis Pasteur discovered that leavening was due to fermentation by the yeast Saccharomyces cereviseae, baker's yeast (or brewers yeast). In many cultures, yeast derived from beer was preferable to that derived from old dough because the yeast derived from old dough imparted a sour taste to bread (sourdough bread). Today, sourdough bread is a specialty. Romans produced yeasts from grape fermentation, although in Spain at the same time, beer froth was used as the source of yeast (leavening). Bakers later came to ferment their own yeast in solutions of hops and malts rather than going to brewers. In the 19th century US, bakers yeast became characterized by some as an "impure and poisonous substance". This lead to the development of non yeast leavening; baking powders.

When it was discovered that yeast were microorganisms, many doctors, claimed that the effects of yeasts on health was no different than those of poisonous molds (the idea was that all microbes are somehow toxic..no actual evidence of course!). These fears lead to the development of mixtures of acids and alkalis (acids and bases) to produce carbon dioxide for leavening using a chemical reaction. Of course, individuals emerged who claimed that these chemicals were harmful to health and should be avoided. Many commercial breads are not raised with yeast, but by mechanical aeration (no doubt, someone thinks this is harmful to your health!) with yeast added for flavor. Baking powders have greatly aided the development of wheat products such as pancakes and biscuits, however, from "self rising flours" that include baking powder.

The identificaion of yeasts as a living organism has allowed for the development of better culturing techniques and better preparations. Yeast are not harmful to health, but rather are a good source of B vitamins and lysine, a limiting amino acid in most cereals.

Brown vs White Bread

We have looked at the issue of preparing bread from the germ only quite a bit already. The notion that white bread is superior to wheat goes back to the earliest days of bread production. Hippocrates noted that bread made from wheat stripped of the bran was more nourishing while bread made from whole wheat was less nourishing, but more laxative. The significance of the whiteness is noted in the reference from Achestratus (who basically "reviewed" the foods of various regions) who descibes the bread made by Eresus as "the best" as it is "so white that it outdoes the ethereal snow in purity".

We have discovered that fiber is an important ingredient in the diet, but that whole wheat does contain compounds (such as phytic acid) that limit the absorbtion  of nutrients to the extent that one does in fact get more nutrient from white bread than from whole wheat bread. It is a little ironic that we fortify white bread but not wheat bread. A diet of whole wheat bread and dairy products caused an outbreak of Ricketts among children in Ireland because of the vitamin D complexing properties of phytic acid (which is located in the aleurone layer).

Thus whole wheat bread does contain more nutients, but also compounds that inhibits the absorbtion of nutrients. Whole wheat bread does contain more fiber, and is thus more laxative. Looks like the Hippocrates was right after all!