

AERATION OF BREAD. 



When bread is made by simply mixing flour with water and baking 

 the dough, the result is a hard, tough, compact mass, "the unleavened 

 bread" of the Scriptures. The use of yeast to "leaven" the dough is 

 doubtless almost as old as the art of baking itself. Both kinds of bread 

 are mentioned in Mosaic history, and its use was known in Sgypt and 

 in Greece at very early periods. Nothing has ever been found that 

 could equal the action of yeast as a leavening agent. Carbonic-acid gas 

 is generated by fermentation from the carbohydrates already existing 

 in the bread, so that no foreign materials are introduced into it. The 

 disengagement of the gas takes place slowly, so that it has its full effect 

 in the lightening of the dough. This is an objection to its use, of course, 

 when quick raising is desirable, and it is this slow action of yeast which 

 has been the chief cause of the introduction of a chemical aerating agent. 



The method of aeration invented by Dr. Danglish, in England, in 

 March, 1859, approximates more closely the action of yeast than any 

 other method in so far as it introduces no permanent foreign substance 

 into the bread. In this method water which has been previously charged 

 with carbonic dioxide is used in making up the dough, the operation be- 

 gin performed in a closed vessel, under pressure. As soon as the dough 

 is taken from this vessel it immediately rises, from the expansion of the 

 gas contained in it. The method has been modified by using instead of 

 water a weak wort, made by mashing malt and flour, and allowing fer- 

 mentation to set in. This acid liquid absorbs the gas more readily, and 

 perhaps has some slight effect on the albuminoids, the peptonization 

 of which constitutes an advantage of yeast raised bread over that made 

 by this method, in which the aeration is purely a mechanical operation. 

 Thus the bread made by this process is somewhat tasteless, the fla : 

 vors produced by fermentation within the bread being wanting. On 

 the other hand, there is no danger of the improper fermentations which 

 sometimes occur, and the process is especially adapted to flours which 

 would be apt to undergo such changes when fermented. Jago 1 says 

 with reference to it : 



Working with flours that are weak or damp or even bordering on the verge of un- 

 soundness, it is still possible to produce a loaf that should be wholesome and palata- 

 ble, certainly superior to many sodden and sour loaves one sees made from low- 

 quality flours fermented in the ordinary manner. In thus stating that it is possible 



1 Chemistry of Wheat, Flour, and Bread, and Technology of Bread-making. Lon- 

 don. 1886. 



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