BUTTER 605 



The starter proper is prepared by mixing 1 quart of the mother 

 starter with about 40 quarts of milk which has been pasteurized 

 and then cooled to 65 to 85 F. This is then incubated for 

 twenty-four hours, after which it is ready to be used with the 

 cream in the proportion of from 5 to 20 per cent. 



The acidity of properly ripened cream is usually given as 

 0.5 to 0.7 per cent. In rich cream the acidity should be lower 

 than in lean cream, because the acid is contained in the plasma, 

 not in the fat, but in measuring acidity the whole volume of cream 

 is considered. The larger the fat content of cream, the smaller is 

 the amount of plasma. 



A considerable quantity of butter is made from pasteurized 

 cream, and the advantages of using such cream are becoming more 

 apparent to butter makers. One advantage is the destruction of 

 pathogenic bacteria; another is the fact that by using pasteurized 

 cream the ripening process can be absolutely controlled. Pas- 

 teurization destroys the majority of bacteria, and by inoculating 

 pasteurized milk with a pure culture starter, ripening proceeds 

 uniformly. The product is always of the same high quality, and 

 has, therefore, commercial advantages over butter made from 

 raw cream. Furthermore, the stability and aroma of the butter 

 are improved. 



The flash process of pasteurization is generally used for cream 

 to be used for butter making. According to Rogers, Berg, and 

 Davis, the temperature for continuous pasteurization should not 

 be below 74 C. (165 F.) nor above 80 C. (175 F.). If pas- 

 teurized below 74 C. the stability of the butter suffers; if above 

 80 C., the flavor is affected. 



The churning process is stopped when the fat appears in small 

 granules. The buttermilk is strained off and the butter remains 

 on the sieve. It is then mixed with clean, pure water, churned, 

 and strained again. This process is repeated until the butter- 

 milk has all been practically removed. The temperature of the 

 water used for washing is gauged according to the consistency 

 of the butter-fat. If it is soft, the water should be cold; if hard, 

 the water should be warm. Salt up to 5 per cent. is then sifted 

 on the butter and worked in. 



The working of the butter is an important process. By work- 

 ing the salt is incorporated, water or buttermilk is removed, and 

 the texture becomes firm unless the working is overdone, in which 

 case the texture becomes greasy. Too much manipulation may 

 have a detrimental effect on the aroma of the butter. This, as 

 stated previously, is largely the result of bacterial activity on the 

 fat. The aromatic split-products are absorbed partly by the fat 

 and partly by the remains of buttermilk. Consequently, if the 



