70 DAIRY CHEMISTRY 



The casein content of butter ranges from one half 

 to three per cent; average butter usually contains 

 about one per cent. An excess of casein and albu- 

 min is usually found in poor butters, causing them to 

 retain a large amount of water and to readily undergo 

 fermentation changes. The ash and salt content 

 ranges from one to three and a half per cent, 

 average butter containing about two and a quarter 

 per cent. The amount of fat in butter ranges from 

 80 to 90 per cent, average butter containing about 

 85 per cent. The fat varies with the water content, 

 those butters which contain the most water contain 

 the least fat, and butters with the highest fat content 

 contain the least water. There is only a general re- 

 lationship between the quality of the butter and its 

 percentage content of water, fat, casein, and ash. 

 Two butters may have the same percentage of these 

 ingredients and be widely different in taste, general 

 physical properties, and commercial value. 



70. Butter Colors. — Normal butter has a charac- 

 teristic yellow color, due to the presence in milk of 

 a distinctive nitrogenous coloring material called by 

 Blyth lacto-chrome. The amount of this coloring 

 matter is influenced by the food consumed and by 

 the individuality of the animal. Milks or butters 

 that do not contain this natural color are con- 

 sidered abnormal, and in order to impart the de- 

 sired color to the butter, a very small amount of 

 butter color is used. Most of the butter colors are 

 made from harmless materials. Occasionally, how- 



