1826.] on the Art of Baking Bread, 1 79 



instances a much smaller quantity would be found completely 

 sufficient; so that, in all probabiUty, three ounces of carbonate 

 of magnesia to every 100 pounds of flour would be found to serve 

 the purpose, provided a due incorporation were effected of the 

 magnesia throughout the substance of the bread. 



The employment of the carbonate of magnesia in thus correct- 

 ing the acidity of dough, appears to possess decided practical 

 advantages when compared with the use of carbonate of soda. 

 It has a remarkable bulkiness and elasticity, so as, when 

 employed in excess, to produce even mechanically a consider- 

 able effect towards the lightness of the bread into which it 

 enters. And it may be remarked that these qualities, together, 

 perhaps, with its tendency to correct acidity, although this 

 latter seems to have been less regarded, caused it to be recom- 

 mended by Mr. Edmund Davy,* as well adapted for raising and 

 improving the sad and doughy bread which was made from the 

 bad flour of harvest 1816. But besides possessing these advan- 

 tages, it is also more tasteless, and a less active chemical ageiit 

 than the carbonate of soda. Accordingly, whenever the acid to 

 be corrected happens to exist diffused through the sponge or 

 dough, as it may be difficult by any care in kneading to incor- 

 porate the alkali equably with the whole mass, it is safest to use 

 magnesia, as an accidental excess of that substance occurring in 

 any part of the bread, will neither materially injure its flavour, 

 nor will any activity of its alkaline powers induce a chemical 

 change upon any of the constituents of the flour. But it may 

 be proper to observe, that whenever the baker is led, by any 

 circumstance, to anticipate the supervening of acescence in his 

 dough, while yet the materials of it are unmixed up, he will do 

 well to mingle the magnesia with the flour before either is wet, 

 and he may thus rest secure that the salutary neutralizing effect 

 of his corrective will be called into action throughout his dough, 

 precisely in proportion as it is required. Its presence being 

 thus extended through all the particles of the dough, no sooner 

 will any acid be generated in any quarter, than it will be 

 neutralized by the alkali. The small quantity of neutral salt 

 which is formed by the mutual action of these two bodies does 

 not appear at all to affect the quality of the bread. And so far 

 from this employment of an alkaline carbonate tending to pre- 

 vent the loaf from rising, wherever that substance is truly called 

 into action, the carbonic acid gas evolved in consequence of 

 its decomposition will materially promote the vesicularity of the 

 bread. 



It is not only, however, from the fermentative process in the 

 dough that the baker has to apprehend the misfortune of sour 

 bread ; for it sometimes happens, though now more rarely by 



* Philosophical Miagazine, vol. xlviii. p. 465. 



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