64 
In the sponges the characteristics of the yeasts appeared to good ad- 
vantage, for not only could the fermentative action be easily determined, 
but also the particular flavor imparted and the keeping properties. The 
sponges were tested first with sterilized flour, then with unsterilized. 
Sponges made with sterilized flour were kept for weeks without giving off 
bad odors. They were then made with unsterilized flour. The odors gen- 
erated during the fermentation varied from pleasant fruity odors through 
pungent odors, flat and insipid odors to decidedly disagreeable odors. 
Some of the sponges would remain in good condition for weeks, whereas 
in others, growths of moulds would appear in a few days or disagreeable 
odors were generated. The breads varied also, some being pleasant to 
the taste, some insipid and a few left a sharp or unpleasant aftertaste. 
Then the texture differed even with as nearly as possible the same amount 
of kneading; some were even-grained, while others would show quite 
an extent of irregularity in the grain. One thing that was quite noticeable 
in all the breads was the lack of any sourness, and on account of this lack 
when the breads are tasted, there seems something missing to which one 
is accustomed. 
The experiments on the whole indicated that if the best results are to be 
obtained in bread-making the yeast will have to be selected with the 
same care that a yeast is for the fermentation of beer or other liquor, A 
yeast should possess certain properties to make it valuable in bread- 
making; it should have a fairly vigorous action, so that the fermentation 
would take place before any deleterious changes could take place in the 
dough; it should impart a pleasant flavor and without any disagreeable 
aftertaste, and should give an even, fine texture to the bread. All these 
qualities could be obtained by taking the same care in the selection of a 
yeast for bread that is now taken in the selection of a yeast for beer. 
Besides, there are great possibilities in the variety of flavors that can 
be obtained from the use of different yeasts. I presume the reason for 
the apathy that exists in regard to the selection of yeasts for bread- 
making purposes is due to the fact that a great deal of the bread is of 
home manufacture, and if not suitable, it is not so easy for one to change 
the base of supplies, so that a good deal of competition is eliminated. 
