MILK AND ITS CARE. 



195 



VI. Working Butter. 



The objects of working are to expel a portion 

 of the water, to mix thoroughly the salt with the 

 butter, and to get the butter into compact, mar- 

 ketable form (Fig. 48). 



The combined churn and worker runs the 

 butter between slowly 

 revolving rollers, and 

 is used almost exclu- 

 sively in large butter 

 factories. The work- 

 ing is continued until 

 the salt is evenly dis- 

 tributed and the grain 

 of the butter shows 

 the right stage has 

 been reached. At this stage the granules of 

 butter almost lose their identity and string out 

 slightly when the butter is broken, instead of 

 breaking straight across. Overworking butter 

 spoils its grain, and insufficient working results 

 in uneven or streaked color of the butter, 

 known as mottling. The latter is a very common 

 and a very objectionable fault in butter. 



VII. Composition of Butter. 



The average composition of butter is about as 

 follows : Fat, 85 per cent.; casein, i per cent.; 

 salt, 2.5 per cent.; water, 11.5 per cent. 



The composition varies considerably, espe- 

 cially the fat and water. Butter of good quality 



FIG. 48. FARM DAIRY BUTTER- 

 WORKER. 

 One of the best for farm use. 



