44 * Report OF THE BACTERIOLOGIST OF THD © 
tories, and would probably have been overlooked in a commercial 
transaction. 
Before and during the time of these experiments the manufac- 
ture of cheese for other purposes was being carried on in the 
same room without any appearance of sweet flavor. A vat which 
had been used in making one of the yeast-infected cheeses, and 
had been cleaned in the usual manner, but without any special 
precautions, was again used, after an interval of two days, in 
making six Young America cheeses, which were distributed 
among the various curing rooms. Upon examination at the end 
of two months they were decided by a number of competent 
judges to show well-marked cases of sweet flavor. An exam- 
ination at this time showed the presence of a goodly number of 
yeasts. 
7 CONCLUSION. 
“Sweet flavor,” as the term is generally used, includes a group 
of undesirable cheese flavors. Clean-flavored cheese contains 
very few, if any, yeasts, while sweet-flavored cheese contains 
large numbers of yeasts, at least during the first stages of ripen- 
ing. 
The addition of starters of certain yeasts to the cheese vats 
has repeatedly resulted in the production of off-flavors, some of 
which would be included under the general term of “sweet 
flavor.” 
IV. RUSTY SPOT IN CHEDDAR CHEESE. 
A discussion of rusty spot in Cheddar cheese may seem out 
of place in a bulletin otherwise given up to the subject of flavors; 
but since this is one of the annoying dairy troubles in the State, 
and has received considerable attention at the Experiment Sta- 
tion during the past two years, a short article upon this subject 
is given here. 
WHAT IS RUSTY SPOT? 
“Rusty spot” is the name given to small yellowish-red points 
or patches scattered quite evenly throughout the mass of the 
cheese and having the general appearance of iron rust. <A closer 
