This is an elastic term, meaning that a certain proportion of bran or germ, or of both, have been added to the flour. It is also applied to bread made from whole-wheat meal. Any bread made with the addition of bran is richer in mineral constituents. Another difference is the amount of water present. The protein of bran converts some of the starch into dextrin, and this keeps the brown bread moist. There is a smaller proportion of carbohydrates in brown as compared with white bread, and a larger amount of cellulose. For this reason brown bread is recommended in constipation.
Of the patent breads the most are of the brown variety. They are made from flours prepared by various patent processes. Some are wholemeal breads, with the bran reduced to varying degrees of fineness. Others contain the germ in various proportions (see Hovis, p. 89).
Others are malted, e.g., Bermaline, Carr's, Veda, etc. The malting consists in adding malt extract. When the malt extract is mixed with the dough, the latter is ultimately converted into malt sugar and dextrin. This makes the bread keep moist, but its activity is stopped as soon as the bread is placed in the oven, the ferment being destroyed by the heat. Thus malted bread does not aid digestion of other starchy food.
Vienna bread is made from the whitest flour (the patents) fermented with compressed yeast, and milk often added to the dough. The crust is glazed by being subjected to the action of overheated steam before leaving the oven.
Pumpernickel is German black bread made with sour dough; it is somewhat laxative.
Zwieback is a thoroughly dry form of aerated bread which is very wholesome for invalids.