190 NEUTRALIZATION 



pleased to get cream in such a sweet condition that it would not 

 be necessary to reduce the acidity for pasteurization. The 

 alkalies most commonly used for reducing the acidity of cream 

 are limewater and soda ash. The authors have never recom- 

 mended the use of any other substance than limewater or milk 

 of lime. The amount of lime used in reducing the acidity, some- 

 what less than one-tenth of i per cent, is so infinitesimal that 

 it passes off in the buttermilk and has no effect upon the butter. 

 The fat-globules of milk being coated with a film, the alkali 

 solution used for reducing the acidity is mixed with the serum 

 or the other component parts of cream rather than the butter-fat ; 

 hence, the small per cent of lime used practically all passes off 

 with the buttermilk. v 



Investigations pursued under the direction of one of the 

 authors showed that butter made from cream of which the 

 acidity had been reduced by milk of lime did not contain any 

 more lime than butter made from whole milk to which no lime 

 had been added, and contained less lime than a number of 

 samples of dairy or farm butter. Investigations of this butter 

 were made at the Universities of Wisconsin, Cornell and Purdue. 

 The explanation of the higher percentage of lime in dairy butter 

 may possibly be that the cream for the farm butter was churned 

 at a higher temperature than the cream from which the butter in 

 the creameries was made. Butter churned at a high temperature 

 will invariably contain a high percentage of casein. In such 

 butter the lime will be held between the meshes of the casein; 

 hence the high percentage of lime found in dairy butter, where no 

 lime had been added to the cream, was undoubtedly due to the 

 high temperature at which the cream was churned. Butter 

 made from cream which has been subjected to reduction of 

 acidity and pasteurization seems to give good satisfaction in the 

 markets. This is particularly true during the storage season. 

 Such butter is then sought by dealers in storage butter, owing to 

 its excellent keeping qualities. 



The use of limewater in milk is of long standing and well 

 known. Lime is an essential constituent of dairy products. It 

 is there to build the bones and to serve other essential physio- 



