DAIRY FARMING^ — DAIRYING. 385 



" The witbdra\val of port of the whey from the vat soon after cutting does 

 not affect the rate of separation of whey from curd, but the remaining whey 

 rises more rapidly in acidity as a result of such withdrawal." 



The effect of stirring when on the racli, in curds of equal acidity but varying 

 in moisture content, was to bring the moisture content to the same figure, but 

 this was not the case when the acidity varied. Stirring the curd on the rack 

 prevented matting. When a curd was well stirred the final moisture content 

 depended to a great extent on its acidity. 



Among the conclusions drawn are the following: 



" Variations in the fat content of milk, within ordinary limits, influence only 

 very slightly the rate at which whey separates from curd, the presence of more 

 fat tending to retard the process. 



" Variations in the percentage of casein or water in milk within ordinary 

 limits have a corresponding influence on the rate of moisture separation, the 

 tendency being always toward the production of cheese with uniform moisture 

 content. The addition of water to milk does not inci'ease the moisture content 

 of the resulting cheese, as the curd from watered milk gives up moisture more 

 rapidly after cutting. 



" The loss of moisture iumiediately after cutting is rapid, but decreases in 

 speed as time passes. The rate is increased when the curd is taken out of the 

 whey and piled. After this it is rapidly decreased and is again increased when 

 the curd is salted. The loss of moisture, per pound of moisture in the curd, 

 is greatest at the time the cui'd is taken out of the whey and piled." 



" High acidity and high temperature induce rapid separation of the whey 

 in)mediately after cutting. If the surface layers of the cubes are dehydrated by 

 too rapid initial whey separation, so as to form a skin covering an interior 

 pulp, the subsequent separation of whey is delayed. The yield of cheese is 

 decreased, due to an excessive loss of fat through the broken curd walls, when 

 such curds are taken out of the whey. Curds from overripe milk should be 

 heated later and more slowly after cutting than curds from sweet milk, in order 

 to avoid the skin-and-pulp condition, to insure complete removal of whey, and 

 to avoid unnecessary loss of fat." 



" During rii)ening the acidity of whey within curd cubes rises much faster 

 and higher than that of the whey surrounding the cubes, because the principal 

 seat of acid formation in the cheese vat is in the curd; wliey gains most of 

 its acidity from the curd." 



The influence of lactic acid on the quality of cheese of the Cheddar type, 

 C. F. DoANE {U. S. Deiit. Agr., Bur. Anim. Indus. Bui. 123, pp. 20, figs. 2). — 

 Thirty-four lots of cheese were purchased in July and August, each lot consist- 

 ing of 8 cheeses, one-half of which were stored in a room at 32° F. for various 

 periods, ranging up to 2 weeks, and the other half similarly placed in a 40° 

 room. In January when these cheeses were scored most of them were tainted, 

 sour, or of undesirable texture. The average score on flavor for the high acid 

 cheese was 27, while the average on the normal acid cheese was 31. 



In another study high acid cheese was made from exceptionally good milk in 

 order to determine the effects of storage on this quality of product. Nine lots 

 were made with varying amounts of acid. The quality of these cheeses was 

 injured in about the same proportion as the amount of acid developed. 



In another experiment 2 lots of cheese were made each day on 8 days from 

 vats of divided milk. One of these lots was worked with sufficient acid in the 

 whey to make a light acid cheese, and the other worked on the same day in the 

 regular way for that factory. The cheese maker in charge of the factory set his 

 milk and drew the whey somewhat sweeter than is customary among the best 



