BISCUIT (pronounced according to the old spelling “bisket,” a Fr. form from Lat. bis, twice, and coctum, cooked, in reference to the original method of preparation; cf. Ital. biscotto, Sp. bizcocho, &c.), a form of unvesiculated bread (q.v.) which is made in thin cakes of various shapes and baked in such a way as to be crisp and short. In the United States of America biscuits of this kind are usually called crackers, but the word biscuit is used there, as also in the north of England, for vesiculated bread baked in little flat loaves or cakes. Earthenware, porcelain, &c., which has undergone its first baking and is ready to be glazed is also known as biscuit or bisque.
The raw material chiefly used in biscuit manufacture is flour, but many other substances, such as butter, sugar, salt, various flavouring essences, &c., are also employed. The flour used by the biscuit-maker differs somewhat from that preferred by the bread-baker. In the main the bread-baker wants flour of some strength, that is to say, flour capable of absorbing a considerable proportion of water and of making a loaf of more or less volume. For biscuits flour strength is not such a desideratum, and as a matter of fact such moisture as is used to make the dough is largely evaporated by the oven; but, except for the commoner kind of biscuits, colour is most essential, as well as sweetness of flavour. In a large biscuit factory several hundred different kinds of biscuits are made, ranging from plain water biscuits to the daintiest fancy biscuits glistening in sugar and piping. The storage required for such an establishment is extensive, but lifts serve to handle both raw material and finished products with a minimum of labour. The flour used by a firm which has a reputation to maintain is sifted as a precaution against the presence of bits of string or other foreign bodies which will make their way into flour sacked by the most careful of millers, and like the butter, sugar and other raw materials, is carefully inspected and tested before being accepted. After blending it is run through a shoot or sleeve to the mixers, which may be of any type used in bakehouses (see Bread). From the mixers or kneaders the dough is delivered on a flat table, or it may go direct to a pair of rolls. These consist of iron rollers with a reversing motion, between which the dough is rolled backwards and forwards into sheets of uniform thickness. The next stage is the feeding of portions of this slab of dough to a cutting and panning machine. In details this apparatus differs as supplied by different makers, but the broad principle is the same in every case. The dough, after first passing through a pair of gauging rollers, which still further thin out the sheet and are capable of regulating its thickness with the utmost nicety, is received by an endless conveyor-band of webbing or similar material. By this band it is carried forward by intermittent motion to a set of punches or stamps which descend on it in quick succession, and serve to mould the surface and cut the edges to the required pattern. This operation completed, the moulded dough passes forward on the same endless band. The dough has now been cut into two distinct divisions, the moulded biscuits and the unworked portion which forms a continuous sheet of a sort of scrap. The latter is separated from the moulded dough, and is carried upwards by another band, which delivers it on a tray or box whence it is returned to the rollers to be reworked. The moulded dough intended for the oven is carried along by the first band and is gently deposited on trays of sheet iron or woven wire. These trays are taken from the machine by boys and placed on the travelling-chains at the oven, or the trays may be automatically moved forward by a travelling-band and placed on the oven. The oven used for biscuit-baking is quite unlike any bread oven. It is much longer and is provided with sets of endless chains moving in parallel lines, and travelling over sprocket-wheel terminals and intermediate supports. The chains have special attachments on which the trays of biscuits are rested, and thus pass them through the oven, and discharge them at the opposite end. Some ovens are provided with a sort of endless belt of iron plates on which the biscuits are placed. These travelling bands are used chiefly for ship and also for dog biscuits, but the most usual type is the oven in which trays are moved on the travelling chains already described. The exact rate of travel, or the time during which the biscuits are in the oven, can be easily adjusted by means of countershafts and leather belts running on cone pulleys fitted at the discharging end. The heat of the oven as well as the rate of travel is varied according to the kind of biscuit, some varieties requiring a gentle heat and a comparatively long sojourn in the oven, while others must be exposed to a fierce heat, but only for a few minutes. The ovens, fired by coke, may be 38 to 50 ft. in length. Their temperature is not generally raised above 500 degrees, but the speed of travel of the trays ranges between 31 and 25 minutes. The whole process of biscuit-making is thus rapid and continuous. The dough is kneaded in the mixers in a few minutes, and when discharged on the dough table is rapidly moulded into the required form by the cutter and panner. By means of endless bands the material is kept moving forwards, whether on the cutter, or in the oven. For certain fancy biscuits special processes are used. Piping and sugar decoration is still necessarily done by hand, and the glaze on some fancy biscuits is imparted by spraying the moulded biscuit with very fine jets of fresh milk. Cracknels are made from a very stiff dough, and when cut out are thrown into coppers of boiling water. They speedily float to the top, remaining apart and not forming into groups. From these coppers they are taken out in trays pierced so as to drain off the water. Then they go into vats of cold water, from which they are again removed, and after being strained of their moisture are panned and baked in a fierce oven. (G. F. Z.)