Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/269

Rh portion of the water held by the flour in its apparently dry state, so that from 10 ft) of flour only about 9 Eb of water biscuits are obtained. The composition of plain biscuit is given by Dr Parkes as follows:—

Water 8 to 11 Nitrogenous substances 15 Dextrin... 3 8 Sugar 1-9 Fat 1-3 Starch 72 to 75

—Under this head is included such bread as is rendered spongiform in structure by the action of carbonic acid within the dough, and which is not baked hard and dry as in the case of biscuits. It includes ordinary loaf bread, pan loaves, French or Paris loaves, cottage loaves, bricks, rolls, buns, and many varieties of fancy bread distinguished by local names and minor differences of form and composition. Vesiculated bread is made in three different ways:— 1st, By the development of carbonic acid within the dough through fermentation of the flour. This is the ordinary and principal method of bread-making. 2d, By mixing the dough with water previously aerated with carbonic acid. The aerated bread made under the patent of the late Dr Dauglish is thus manufactured. 3d, By the disengagement of carbonic acid from chemi cal agents introduced into the dough. Dodson s patent unfermented bread comes under this head, and the &quot; baking powders&quot; and &quot;yeast powders&quot; extensively sold consist generally of carbonate of soda or ammonia and citric or tartaric acid, which evolve carbonic acid in presence of water.

Fermented Bread.—The manufacture of fermented or leavened bread is, as has already been hinted, of very great antiquity, and it is still by the fermentation process that bread is chiefly made. In ancient times leaven was em ployed to induce fermentation in dough (&quot; a little leaven leaveneth the whole lump,&quot; Gal. v. 9), and to this day Parisian bakers, who excel all others in the quality of the bread they produce, chiefly use the same ferment. Leaven is simply a portion of dough, put aside from a previous baking, in which the fermentative action has reached an advanced stage of activity. Yeast, however, has been used as a ferment from an early period, and it appears that it was first so employed in France. Pliny says (Nat. Hist., xviii. 12), &quot; Gallise et Hispaniae frumento in potum reso- luto, spuma ita concreta pro fermento utuntur; qua de causa levior illis quam cseteris panis est.&quot; The use of yeast appears to have died out in France, but was revived again towards the end of the 17th century, when its reintroduc- tion was violently opposed by the Faculty of medicine of Paris. Yeast is now used by Parisian bakers for fancy bread and pastry only. The baking of fermented bread involves three distinct operations, which are technically denominated &quot; setting the sponge,&quot; making the dough or kneading, and baking or firing. It will be convenient first to describe these pro cesses as they are conducted in a London bakehouse. The first duty of the baker is to mix a ferment, which consists of a mixture of potatoes, yeast, and flour. The potatoes, in the proportion of 6 fl&amp;gt; to a sack of flour, are boiled and mashed in a tub, and water is stirred in till the mixture is reduced to a temperature of from 70 to 90 Fahr. About 2J pints of yeast and 12 Ib of flour scalded in boiling water are then added, and the whole forming a thin uniform paste is set aside for several hours, during which it undergoes an active fermentation. Setting the sponge consists in mixing the ferment in a large trough with flour and water sufficient to make the whole into a rather stiff paste. The flour used at this stage, when &quot; full sponge&quot; is made, should be about one-half the entire quantity intended to be used in the &quot; batch,&quot; and the ingre dients have to be thoroughly incorporated by the workman stirring them laboriously together with his arms. The operation occupies from twenty minutes to half an hour, and when ready the sponge is covered over and allowed to rest for several hours according to the temperature at which it is maintained. Generally in from four to five hours the sponge &quot; rises ; &quot; fermentation has been going on, and carbonic acid steadily accumulating within tho tenacious mass till it has assumed a puffed out appearance. By degrees the sponge gives off the gas in puffs, and the mass begins to collapse, till what was a swollen convex surface assumes a somewhat concave form, the centre be ing depressed while the sides adhere to the edges of the trough. The workman judges by the amount of collapse the time the sponge is ready to be taken in hand for kneading or making the dough. This process is thus described by an eye-witness: &quot;The batch consisted of a sack and a half of flour, nearly one-half of which had been used in making the sponge. Two men com menced breaking the sponge at 1.4 P.M. Having poured the water into it, they plunged their arms in and stirred it about until it became of the consistency of thin batter. At 1.10 they began to mix the dry flour with it, immediately upon doing which they were enveloped in a cloud of flour dust, their heads being bent down to within a few inches of the mass they were handling. Flour and pieces of dough were splashed over the trough, upon the floor. At 1.12 a, third man was added. Their hair, caps, and face powdered thickly with the dust, a thick cloud of which was thrown up with every movement, especially when large masses of dough, as it became a little solid, were taken up in their arms and thrown upon the rest, fresh flour being first strewn between. At 1.15 one of the men became very red and heated. The other two were very pale, and did not show any perspiration. At 1.16 the cutting off of large masses began, as much as two men could lift to place over the adjoining mass. At 1.23 the men began to pound the mass with their fists. At 1.26 one of the pale men, who was also very thin, began to look red and hot. At 1.29, after smoothing the mass down, they began again to pound it with their fists. At 1.30 it was again smoothed over, the sides of the trough scraped, and a little dry flour thrown over it. It was then considered finished.&quot; After this laborious process the finished dough is covered over for some time, varying from half an hour to two hours accord ing to the temperature, during which fermentation again begins, and the mass is &quot; proofed.&quot; It is then &quot; scaled off,&quot; i.e., weighed on scales in pieces of 4 Bb 4 oz., if 4-B&amp;gt; loaves are to be made, or half that amount for 2-tt&amp;gt; loaves ; and as rapidly as weighed it is &quot; moulded &quot; into the form of the loaf, when it is ready to put into the oven. Flour of good quality will take up about 17 gallons of water in course of the foregoing operations, and before putting into the oven the inredients of a 4-fi&amp;gt; loaf will be—

lb Flour ...................................... 3 Water ..................................... 1 Yeast ..................................... Potatoes .................................. Salt ....................................... oz. 2 Ok A loaf ready for going into the oven has about half the bulk it attains during the process of firing. Batches of cottage and household loaves are packed close side by side on the sole of the oven, the sides of each loaf being rubbed with butter to prevent them from adhering to each other, and they are consequently crusted on the top and bottciu only. Pan loaves are baked each in separate tinned pans of the form of the loaf, and Parisian loaves are baked end to end in long tinned pans. The firing of bread in the oven occupies from 1 to 1| hours, the temperature at the 