New YorkK AGRICULTURAL EXPERIMENT STATION. 15 
DBPARTMENT OF BACTHRIOLOGY. 
The following work has been carried on by the bacterfological 
department with the active codperation of the dairy expert on 
all points which called for a knowledge of practical conditions. 
Fishy flavor in milk.—An outbreak of this trouble was traced 
to the milk of a single animal. This cow seemed in good health 
but the milk possessed this intensely disagreeable flavor when 
freshly drawn. By tainting all the milk with which it was 
mixed the product of this one cow had caused a marked falling 
_ off in the business of a city dealer. All trouble ceased when the 
milk of this one animal was rejected. No biological cause for 
the flavor could be discovered. 
Bitter flavor in Neufchatel cheese—An outbreak of the trouble 
in a factory was studied and found due to the activity of certain 
kinds of bacteria. By making cheese from samples of the milk 
of each patron the source of the trouble was located and re- 
moved. : | 
Sweet flavor in Cheddar cheese—Work upon this subject has 
been continued throughout the year. It has been found that 
while yeasts occur but rarely in clean-flavored cheese they are 
regularly present in considerable numbers in all cheese selected 
for our study by cheese experts as typical examples of sweet 
flavor. This opens up an entirely new field concerning the rela- 
tion of yeasts to bad flavors in cheese and work is being continued 
along this line. 
Rusty spot in Oheddar cheese-——Reports seem to show an. in- 
crease in trouble from this source during the present year. The 
bacterium causing the trouble was isolated from the product of 
factories in three different counties and its action studied when it 
was introduced into the cheese vat. When cultures of the germ 
were mixed with the milk before adding the rennet, little dis- 
coloration of the cheese resulted; but when introduced into the 
vat after the curd was cut, the cheese became very red. 
This would seem to indicate that the time of introduction is 
important, and that infection from the factory and utensils is a 
- more probable source of harm to the cheese than introduction 
