PASTEURIZATION 191 



If the mixed cream is neutralized in the forewarmer, as is 

 done in most creameries receiving sour cream, the danger of 

 abnormal curd formation is removed, and it is not necessary to 

 hold the cream in the forewarmer after neutralization. In case 

 the cream is neutralized it is desirable to use two or more fore- 

 warmers of suitable capacity, usually holding 250 to 300 gal- 

 lons, so that, while one forewarmer is being filled, the cream 

 in the other may be neutralized and passed through the pasteur- 

 izer. The use of numerous forewarmers has the advantage of 

 speeding up the work, increasing the capacity of the plant and 

 assisting the continuity of operation of the pasteurizer. 



Thin, sour cream is prone to suffer more intense curdling 

 action, to cause more difficulty in the pasteurizer and to produce 

 greater loss of fat in the buttermilk, than cream of reason- 

 able richness, testing 30 to 35 per cent fat, and averaging about 

 33 per cent fat. Excessively rich cream, while desirable from 

 the standpoint of economizing vat and churn space, is objection- 

 able, because it is deficient in milk solids not fat, which are 

 necessary to protect the fat globules against mutilation in the 

 pasteurizer. Such cream, when pasteurized is apt to yield but- 

 ter with a greasy or salvy body and an oily flavor, which may 

 later develop into other and more damaging off-flavors, such as 

 metallic and fishy flavor. 



It is advisable to standardize all cream in the forewarmer 

 for fat to about 33 per cent fat, and for acid to about .25 per 

 cent acid. Dilution of the cream with water, such as occurs 

 when the cream cans and the vats are rinsed with water, or 

 when the standardizing of rich cream is done with water, 

 should be avoided, because such dilution lowers the per cent 

 of non-fatty constituents in the cream. The cans should be 

 freed from the remnants of cream by inverting them over a 

 steam jet, (see paragraph on Can Washing, Chapter IV,) and the 

 standardizing of rich cream for fat should be done with sweet 

 milk or skim milk or redissolved skim milk powder. For stand- 

 ardizing the acidity, see Chapter VII on Neutralization of Sour 

 Cream. 



The flash pasteurizer should be set high enough to make 

 unnecessary excessive elevation of the cream by the pasteur- 

 izer. The greater the elevation to which the pasteurizer must 



