1826.] on the Art of Baking Bread;:^^ "^^ 181 



preparation of the dough. M. Vogel has further ascertained, in 

 an experiment already quoted,* that about one-fourth of the 

 whole quantity of the starch had been converted into a gummy 

 matter possessing the characters of torrefied starch, and which, 

 like it, was soluble in cold water. The gluten also, though 

 little changed in amount, as the experiment of Vogel shows, is 

 certainly so far affected, while in the oven, as to sustain a disunion 

 of its particles, and to be thereby deprived of much of its adhe- 

 siveness and elasticity. But of the nature of these alterations, 

 little further has been determined. 



When these several changes have taken place, when the bread 

 has gradually swelled to about double its bulk in the oven, and 

 has acquired its upper and under crust, or, in other words, has 

 become slightly torrefied in those parts which are immediately 

 exposed to the high temperature either of the glowing floor or 

 of the heated air of the oven, the loaf may be withdrawn, and 

 requires only to be thoroughly cooled in order to exhibit a fair 

 specimen of the perfection to which the modern art of bread- 

 baking has been carried. Although it is, perhaps, impossible 

 to assign with unerring precision to each of the several consti- 

 tuents of flour its peculiar function, and to each detail of process 

 its precise effect, towards completing the perfect result of a well- 

 made loaf, yet it may be a matter of some interest briefly to 

 specify the peculiar share which the present state of our inform- 

 ation would guide us to assign to each in the system. The 

 moistening of the flour with water and the kneading of it into a 

 homogeneous mass, is the first step towards forming the rudi- 

 ments of the future loaf. The saccharine principle of flour, 

 while it serves the purpose of communicating to the bread an 

 agreeable relish, may also be with certainty regarded as the 

 subject of that chemical fermentation which introduces carbonic 

 acid gas into the system of the dough. Thus there is generated 

 the elastic fluid within the bread which gives it lightness and 

 vesicularity. The gluten of the flour, an ingredient peculiar to 

 the farina of that vegetable, is of use in binding and cementing 

 all the particles of dough into one cake, by means of the mecha- 

 nical process of kneading ; besides, by its tenacity, when duly 

 diffused throughout a loaf, it extends and dilates within the oven 

 into a thousand little cells, to imprison the contained gas, as it 

 expands by the heat. And the remaining ingredient, starch, is 

 not only the great basis of all bread, and the main source of 

 nutriment in each loaf, but besides, in the oven, becoming rigid 

 through the action of heat, it materially assists the permanent 

 fixation of the particles of the loaf while in its most expanded 

 form ; it is often the means of yielding a certain supply of sac- 

 charine matter ; and there is also a considerable portion of its 



* Journal dc Pharmacie, vol. iii. p. 219. 



