Kneading is the process of making the stiff paste of flour and water for being afterwards baked into bread. It is usually effected by a sort of pommeling action of the hands and arms, and sometimes of the feet of the bakers. A variety of machines have been at different times proposed for superseding the barbarous process we have just mentioned; they have however been but very partially adopted, the bakers in general preferring to continue their "good old-fashioned" dirty practice. "Pain a la mecanique" is, however, fashionable in Paris, and, it is to be hoped, will ere long become so here. It is said that at Geneva all the bakers of that city are compelled by law to send their dough to be kneaded at a public mill constructed for that purpose. At Genoa, also, mechanism is employed for kneading; the apparatus employed at this place has been published in several of the journals, from which it appears to be so rude and ill-contrived as not to need a description in this place.
1. The petrisseur, or mechanical bread-maker, invented by Cavallier and Co. of Paris, seems to us to be nearly the best hitherto introduced. This consists of a strong wooden trough, nearly square, with its two longest sides inclined, so as to reduce the area of the trough in the direction of its width, and adapt it to the dimensions of a cast-iron roller, the axis of which passes through the ends of the trough; the bottom of the trough is semi-cylindrical, leaving a small space between it and the roller, which space is adjustable by levers. All along the top of the outside of the roller, is fixed a knife edge, which, with the roller, divides the trough into two compartments. Upon the axis of the roller is a toothed wheel, which takes into a pinion; this pinion is turned by a winch, and communicates thereby a slower motion to the roller, and the roller, by its rotation, forces the materials or dough through the narrow space before mentioned, left between it and the bottom of the trough; the knife edge on the top of the roller preventing the dough from passing by it.
Being thus all forced into one of the compartments, the motion of the roller is reversed by turning the winch the contrary way, which then forces the dough back again through the narrow space under the roller into the first compartment; in this manner the working of the dough, alternately from one compartment to the other, is continued until completed. . .
2. Another plan was to make the trough containing the dough revolve with a number of heavy balls within it. The trough in this case is made in the form of a parallelopipedon, the ends being square, and each of the sides a parallelogram, whose length and breadth arc to each other as five to one. One side of the trough constitutes a lid, which is removed to introduce the flour and water, and the trough is divided into as many cells as there are balls introduced. The patentee states, that by the rotation of the trough the balls and dough are elevated together, and by their falling down the dough will be subjected to beating, similar to the operations of the baker's hands.
3. Instead of employing a revolving cylinder, it is fixed, an agitator is made to revolve, having a series of rings angularly attached to an axis, extending the whole length of the trough.
4. Mr. Clayton, a baker of Nottingham, had a patent in 1830 for a machine somewhat similar to the last mentioned, inasmuch as a set of revolving agitators are employed to produce the kneading action; the agitators are longitudinal bars, fixed to arms, which radiate from the axis, and they are forced through the dough in their revolution; but the cylinder in which they revolve, and which contains the materials, is made to revolve at the same time in a contrary direction; the motion of the latter being imparted by a short hollow axis, while the axis of the former is solid and passed through the hollow one. The solid axis, which is turned by a winch, has on it a bevelled pinion, which, by means of an intermediate bevelled wheel, actuates another bevelled pinion fixed on the hollow axis, and therefore causes it to revolve in the opposite direction. These two simultaneous and contrary motions constitute the novelty claimed by the patentee, who states, that dough-making machines, similar to his own, have all failed for want of such an arrangement.
This statement, coming from a baker, commands attention; but we cannot concur in its truth, since we know that the following plan of a kneading machine works well without opposite simultaneous motions, and without any agitators or beaters, which absorb a great deal of power without producing an adequate effect.