BREAD. (Ger. brod.) This impor tant article of food is made of the flour of different grains ; but it is only those which contain gluten that admit of con version into a light or porous and spongy bread, of which wheaten bread furnishes the best example. When flour is made into a tough paste or dough by the ad dition of a little water, rolled out into thin cakes, and more or less baked, it forms biscuit. For the formation of bread a certain degree of fermentation, not unlike vinous fermentation, is requi site, care being taken to avoid acetous fermentation, which renders the bread sour, and to most persons disagreeable. If dough be left to itself in a moderately warm place (between 80° and 120°), a degree of fermentation comes on, which, however, is sluggish, or, if rapid, ace tous; so that to effect that kind of fer mentation requisite for the production of the best bread, a ferment is added, which is either leaven or dough which is already in a fermenting state, and which tends to accelerate the process in the mass to which it is added ; or yeast, the peculiar matter which collects in the form of scum upon beer in the act of fermenta tion. Of these ferments leaven is slow and uncertain in its effect, and gives a sour and often slightly putrid flavor. Yeast is more effective ; and when clean and good, it rapidly fer mentation ; but it is often bitter, and sometimes has a peculiarly disagreeable smell and taste.
All, then, that is essential to make a loaf of bread is dough to which a certain quantity of yeast has been added. This mixture is put into any convenient mould or form, or merely shaped into one mass ; and after having been kept for a short time in rather a warm place, so that fermentation may have begun, it is subjected to the process of baking in a proper oven. Carbonic acid is generated ; and the viscidity or texture of the dough preventing the immediate escape of that gas, the whole mass is puffed np by it, and a light porous bread is the result. Along with the carbonic acid traces of alcohol are at the same time produced, but so insignificant and impure as not to be worth notice ; hence the attempts which have been made to collect it upon the large scale have entirely failed. in an economical point of view. Other flour besides that of wheat will, under similar circumstances, undergo panary fermen tation; but the result is a heavy, un palatable, and often indigestible bread ; so that the addition of a certain quantity of wheat flour is almost always had re course to. It is the gluten, in wheat
which thus peculiarly fits it for the man ufacture of bread, chiefly in consequence of the tough and elastic viscidity which it confers upon the dough.
It is well known that home-made bread and baker's bread are two very different things : the former is usually sweeter, lighter, and more retentive of moisture ; the latter, if eaten soon after it has cooled, is pleasant and spongy ; but if kept for more than two or three days, it becomes harsh and unpalatable. The cause of this difference may perhaps be obvious from the following details of the operations of the wholesale baker.
In making his dough he takes the water, or part of which he intends to use, and having slightly warmed it, dis solves in it a certain portion of salt ; then lie adds the yeast, and then a certain quantity of flour. This mixture is set aside in a warm place, where it soon be gins to ferment. This process is called setting the sponge ; and according to the relation which the water in it bears to the whole quantity to be used in the dough, it is called whole, half, or quar tern sponge. The evolution of carbonic acid causes the sponge to heave and swell • and when the surface bursts it subsides, and then swells again, and so on but the baker is careful to use it before this fermentation has communi cated sourness to the mass. He then adds to the sponge the remaining quan tity of flour, water, and salt, which may be required to form dough of proper quality and consistence, and incorporates the whole by long and laborious knead ings till the entire mass acquires unifor mity, and is so tough and elastic as to bear the pressure of the hand without adhering to it. It is then left for a few hours, during which fermentation goes on ; and the inflated mass is again kneaded, so as to break down any lumps or portions which had accidentally escap ed diffusion in the first operation, and to confer perfect uniformity on the whole. The dough is then weighed out into loaves, which are shaped, and put aside in a warm place for an hour or two, during which they swell up to about double their original size ; they are then put into the oven and baked : *during which ope ration they again enlarge considerably in bulk, in consequence of the dilatation of the previously generated carbonic acid pent up in the dough ; for, as soon as the mass is exposed to the heat of the oven, the fermentation is put an end to.