108 Tbaxsactioxs of the American Ixstitute. 



rye and malt contain relatively less gluten and more gum and sugar 

 than pure rye or wheat meal. The foam from this fermenting mass, 

 washed and pressed, is largely mnde at Rotterdam and exported to 

 England, under the name of German harm. This substance is known 

 to us, mixed with l)ran and dried, under the name of yeast-cakes. 

 These forms of ferment have the advantage, that they he made com- 

 paratively pure, that is, composed of the yeast plants that will yield 

 alcohol and carbonic acid. When mixed with a large quantity of 

 boiled potatoes (chiefly starch), they will yield precisely what is 

 wanted to puff the bread up, make it light, and impart to it a 

 delicious aroma that leaves nothing to be desired. But to secure this 

 result, wliat must you be sure to do? As tlie acetic and putrid 

 fermentations follow closely on the alcoholic, you cannot rely on your 

 potato-yeast as a source of leavening for more tlian a very feAV days. 

 You must be prepared to renew it frequently. The dough must not 

 be allowed to cool, but must be maintained at an even temperature of 

 some 80 deg. to 90 deg., and when it has attained the requisite porosity, 

 and before acetic fermentation sets, it must be placed in a hot oven. 

 If neglected, so as to permit the formation of either acetic or lactic 

 acid, the gluten will be liquified more w less, its tenacity will be lost, 

 and the bubbles will run together, producing a few large instead of 

 numerous small pores, and the dough will be liable to collajise, and 

 become heavy and sodden. 



Alcoholic Fermentation. 



I assume that you have the genuine yeast plant, suited, with proper 

 care, to the ultimate production of alcohol and carbonic acid, and 

 these alone; but when you take into account what shocking com- 

 pounds are sometimes produced, as beer, or ale, or whisky, and the 

 susceptibilities of ferment to the influences of temperature and time, 

 3'ou will readily understand that the pure yeast plant is rather ideal 

 than actual. There is an amusing prejudice in some parts of our 

 country, not wholly confined to the less informed portions of commu- 

 nities, on the subject of alcoholic fermentation in bread. In a report 

 on bread, prepared a few years ago by a generally well informed gen- 

 tleman, wlio happened to be a clergyman of Massachusetts, for an 

 annual agricultural festival, the chairman dwelt upon the duty of 

 every j'oung lady to know how to make good bread. It was quite 

 easy. It required attention to only two or three particulars : there 

 must be good flour, a hot oven, and the fermentation must be care- 



