214 ALCOHOL, VINEGAR, SAUER KRAUT, TOBACCO, SILAGE, FLAX. 



produce a vigorous action. Yeast is sometimes added. As a rule, 

 the fermentation is allowed to continue as long as it will, after which 

 the wine is bottled and thus preserved for use. 



Cider. This is nothing but apple wine, and is made in large 

 quantities in sections of the country where apples are abundant. 

 The expressed apple juice is seldom treated at all, but left to ferment 

 spontaneously. The amount of sugar in apple juice is small, and 

 the completely fermented product contains a proportionately small 

 amount of alcohol. Sweet cider is a name given to the product 

 while it is still fermenting; it contains but a small amount of alcohol, 

 but is filled with the carbon dioxid gas that is produced by the 

 fermentation. Hard cider is the name applied after the fermenta- 

 tion is nearly or quite over, when the evolution of CO 2 has ceased 

 and the alcohol is at its maximum. In the making of cider, as in 

 most other fermentations, great improvements have been made in 

 recent years by the application of the discoveries of bacteriologists. 

 The use of pure cultures of yeasts, in the place of spontaneous 

 fermentation, makes the product of a better character and the fer- 

 mentation more uniform. Numerous other improvements have 

 been made in the details, so that this product, formerly made on the 

 farm in a haphazard fashion, without care and with little or no 

 knowledge of the processes, is now made on a larger scale in special 

 cider factories, resulting in a cider of a much higher quality. 



Yeasts in Bread Raising. The most common use of yeast 

 is in the raising of bread. All nations and all peoples have been 

 accustomed to make bread from the flour of different grains. The 

 earliest method was simply to stir the flour in water and bake 

 the mixture into a hard, unleavened bread. The next step was 

 to allow the dough to stand for a number of hours in a warm place 

 until it became somewhat swollen by the gas formed within it, 

 and then. to bake it. The gas made the dough porous and resulted 

 in a bread filled with holes, easier to masticate, of better flavor, and 

 more easily digested. This was leavened bread. The next step 

 was to take a little of the leavened dough and mix it with the next 

 lot of fresh dough, to hastenen the leavening, a process that was 

 simply inoculating the dough with the yeast organisms in the 



