YEAST BREWS 83 



other kinds, and is sometimes slightly bitter, thus explain- 

 ing the difference sometimes noticed in the flavor of baker's 

 and homemade bread. This type of yeast does not pro- 

 duce so vigorous a form of fermentation in flour as com- 

 pressed yeast, and is less satisfactory in a household. Its 

 use even by bakers has largely ceased. 



Cultivation of Yeast Brews. When one is near a mar- 

 ket, by far the most convenient method of obtaining yeast 

 for bread making is to purchase the compressed cake ; 

 but when one is far from market a fresh supply is not 

 easily obtained. Moreover, we have noticed that if yeast 

 is needed in large quantities the compressed yeast is some- 

 what expensive. It is then certainly cheaper and may 

 sometimes be more convenient to brew one's own yeast. 

 Brewing yeast is a very easy process if one will exercise 

 a little care. 



First one prepares a mixture known as the brew, in 

 which the yeast will grow readily; and then he inoculates 

 this mixture with a small quantity of yeast from some 

 good source and allows the material to grow. Many 

 varieties of mixtures are in use for the development of 

 yeast. Two good formulae are as follows. 



(i) I lb. potatoes (2) Yz lb. of malt 



%, oz. hops Yz oz. of hops 



I gal. water i gal. of water 



To prepare the first of these mixtures, boil the potatoes 

 and remove the skins ; boil again until thoroughly soft, and 

 then mash finely. Meantime the hops are to be heated 

 with the water to nearly the boiling point for a couple 

 of hours, to dissolve the hop extract. After this the 



