356 Bulletin 257, 



slow to shrink up before salting. In extreme cases the 

 whey tank may boil as though heated by fire. 



Cause. 



(i) Yeasts. These enter the milk on hay dust and from leaves 

 of trees. They grow and multiply most rapidly when 

 milk is kept at temperatures above 60° Fahr. 



(2) Returning sour or unpasteurized whey in milk cans aggra- 

 vates the trouble. 



How to prevent. 



(i) Milk should be kept free from dust, and should be cooled 

 to at least 60° Fahr. as soon as milked. 



(2) Use a clean commercial starter. 



(3) The whey should be pasteurized and the tanks cleaned every 



day. 



(4) If the trouble is already present, the whey tank, all factory 



utensils and all patrons' milk cans and utensils should be 

 thoroughly cleaned and scalded. 



Remedy. 



(i) Add the rennet early. 



(2) Heat curd in the whey a few degrees higher. 



(3) Draw off the whey with as little acid as is practical, but 



have the curd well firmed first. 



(4) Do not pile the curd high unless gas is present. 



(5) If gas is present, more acid must be developed at dip- 



ping, but the curd should be stirred dr\'er. 



(6) After milling, if the curd tends to become mushy, one-half 



the salt should be applied. When the curd is well shrunken, 

 apply the other half. 



J. Gassy Cheese. 



Indicated by the presence of pin-holes. They usually have a 

 bad flavor, are spongy, and the curd may float on the 

 whey in the early stage of manufacture. 

 Cause. 



(i) Gassy milk produced by bacteria which are carried in by 



dirt. 

 (2) Gassy starters. 



How to prevent. 



(i) Gassy milk should not be accepted from any patron. 

 (2) Gassy starters should not be used. 



