Bread was one of the earliest foods of man. That it was used long before history was written, the discoveries of modern times have shown us. In Switzerland, in the lake dwellings of prehistoric times, there have been found not only stones for grinding meal and baking bread, but even bread itself, in the form of round cakes. The first mention of bread in literature is in Genesis, in the words of Abraham to the angels, "I will fetch a morsel of bread." The Egyptians knew the art of breadmaking, and baked loaves and cakes in great variety of form and flavor. One ancient Greek writer names sixty-two kinds of bread in use; and in Rome there were many bakeries, where not only was the baking of bread done, but the grain was pounded and sifted, to prepare it for use.
In our own day bread is found in a great variety of forms, many of them characteristic of certain nations; familiar examples are the black bread of Germany, the oat cakes of Scotland, the hard rye cakes of northern Sweden, baked only twice in the year, and the passover cakes or unleavened bread of the Jews.
Bread forms the staple food of a large section of the human race, and is often the only means of subsistence of the very poor. Mr. Goodfellow, in some investigations made in London, found that in the worst districts fifteen per cent of the children ate only bread for the twenty-one meals of the week, while forty per cent more had other food only two or three times a week.
It is essential that so universal a food should be nutritious, palatable, and digestible. To fulfil these conditions, the flour used must be rich in nutriment; the bread must be light and porous, that as large a surface as possible may be exposed to the digestive juices; and the cooking must develop the flavor, and render the food materials assimilable to the greatest possible extent. The necessary ingredients of bread are flour of some variety and liquid for moistening it. Salt for flavoring is required by almost every one, and to most of us the term bread implies some agent for lightening the dough.
Wheat is the flour most commonly employed not only because of its widespread growth but because of the presence in it of the proteid called gluten, or more strictly speaking, of the proteids that upon the addition of water form gluten. Gluten is an important aid in the making of bread light in that being an elastic tenacious substance it retains the gas as it is formed in the dough. In the process of cooking, the gluten hardens and thus enables the loaf to retain its shape. This function of gluten may be compared to that of soap in the water from which soap bubbles are blown.
If some gluten be prepared from flour, as in the experiment on page 41, and baked, the value of this substance in lightening the dough will be appreciated.
Of the other cereals, rye makes the lightest bread as its proteids form with water a sticky substance not so elastic or tenacious as the gluten of the wheat, but sufficiently so as to retain much gas. Corn flour, however, makes only a flat and crumbly loaf unless Qgg be added to increase the elasticity of the dough.
The most desirable bread flour is one rich in gluten.
DIAGRAM SHOWING COMPOSITION OF A LOAF OF BREAD.
Even very hard macaroni wheat may be made into excellent bread as has been shown at the South Dakota Agricultural Experiment Station. If a flour poor in gluten and rich in starch is to be used a stiffer dough must be made than with the opposite conditions. In spite of the efforts of the manufacturers to maintain a constant standard in flour each barrel varies somewhat, and slightly different treatment may be needed.