44 Report of the Bacteriologist of thh 



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. 



C0>rCLUSI0N. 



" 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 vSPOT 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 



