1 826 .] * on the Art of Baking Bread, 



the fermentation of dough, would sustain no change in its 

 appearance or chemical properties, though exposed, either 

 per sCf or mixed with yeast, to the temperature just mentioned ; 

 yet the fermentative process in dough is strong and activ6 under 

 these very circumstances. Besides, it is certain, that if sponta- 

 neous decomposition either of the starch or of the gluten, always 

 .of comparatively tardy excitement, were once commenced and 

 left unchecked in circumstances so favourable to decomposition 

 as in the baking process, with respect to both moisture and 

 temperature, it would of necessity continue proceeding, with 

 regular and unabated energy, so long as a particle of either 

 substance remained unaltered. But in dough, though ferment- 

 ation commences soon after the mixture of yeast and hot water 

 with the flour, and goes on actively and in full vigour for a given 

 period, varying from 24 to 48 hours, \i suddenly stops short j while 

 yet it is quite obvious that much of the starch and of the gluten 

 remains untouched. In fine, it may be mentioned, as conclusive 

 of this question, that when fermentation has thus ceased it^ 

 dough, neither the addition of fresh yeast, nor of fresh starch, 

 nor of fresh gluten, nor of all the three combined, has the 

 smallest effect in renewing the process of fermentation. And it 

 has been ascertained by M. Vogel, that in baked bread, there 

 exists pretty nearly the same quantity of gluten as in common 

 wheaten flour, and that of the starch, three-fourths remained 

 entire ; while the other fourth had only been converted into a 

 gummy matter, similar in appearance and properties to torrefied 

 starch, a change which, it is almost unnecessary to mention, 

 could have no effect in infusing a gaseous body into the bread. 

 It seems, therefore, to be a point scarcely admitting of addi- 

 tional proof, that it is neither the starch nor the gluten which is 

 concerned in the ordinary fermentative process, which takes 

 place in dough. 



We are too little acquainted with the chemical nature of the 

 albuminous and gummy principles which are found to exist, in 

 a minute proportion, in wheaten flour, to be able to reason, with 

 equal precision, on the changes which they may undergo, or the 

 influence which they may exert in the fermentation of dough. 

 But besides their very trifling amount, there exists this strong 

 probability of their remaining entirely quiescent, at least during 

 the early stage of the fermentation of the dough ; — that neither 

 albumen nor gum appears to possess a greater tendency to pass 

 into a state of spontaneous decomposition, than gluten on the 

 one hand, or than starch on the other. 



If we now turn to the other principal constituent of flour, the 

 saccharine principle, a very simple solution of the difficulty will 

 appear, and a natural account of the common fermentative 

 process be obtained. 



And here one can scarcely avoid expressing a certain degree 



