78 Dr Colquhoun on the Art of baking Bread. 



tion, as for causing the dough to expand, in the process of 

 baking, into a light spongy bread. The subcarbonate of 

 ammonia, on the contrary, a substance frequently employed 

 by bakers for rendering dough porous, afforded very favour- 

 able results; and the experiments made by mixing dough 

 with an alkaline carbonate or the carbonate of magnesia, and 

 then decomposing the salt by means of an acid, were likewise 

 satisfactory. The bread made with the latter, though decid- 

 edly inferior to common loaf-bread, was light and porous when 

 compared to that made with unfermented dough. 



But the most novel facts contained in the second part of the 

 essay regards the manufacture of gingerbread, the forma- 

 tion of which is thus described : " The ingredients are flour, 

 treacle, butter, common potashes, and alum. After the butter is 

 melted, and the potashes and alum are dissolved in a little 

 warm water, these three ingredients, along with the treacle, 

 are poured among the flour which is to form the basis of the 

 bread. The whole is then thoroughly incorporated together, 

 by mixture and kneading, into a stiff' dough. Of these several 

 constituents, the alum is found by the baker to be the least 

 essential, although it is useful in having a decided tendency to 

 make the bread lighter and crisper, and in accelerating the 

 tardy period at which the dough is in the most advantageous 

 condition for being baked into bread. For it is one of the most 

 remarkable parts of the present system of manipulation, that 

 gingerbread-dough, however thoroughly kneaded, almost inva- 

 riably requires to stand over for the space of from three or four 

 to eight or ten days, before it arrives at that state which is best 

 adapted for its rising to the fullest extent, and becoming duly 

 gasified in the oven. And experience has shown, that it may 

 be allowed to stand over even for the period of several weeks, 

 rather with advantage than loss in this respect. It is true, that, 

 from causes not well understood by the baker, the dough of 

 gingerbread becomes thus matured and ripe for the oven, on 

 some occasions much more speedily than on others ; but, in 

 general, if the dough were fired at an earlier period than has 

 just been mentioned, the baked bread would more or less 

 resemble in compactness a piece of wood, in proportion to the 

 time by which its baking had been prematurely hastened."" 



