Butter
Butter is produced by placing cream in a proper apparatus and agitating or churning it until the fat globules coalesce into lumps. These lumps are then taken out of the serum known as the buttermilk and the water and milk worked out until it becomes more or less solid. When butter has had the milk and water worked out of it the constituents should be in about the following proportions: Fat, 83.5%; curd, 1.0%; ash, 1.5%; milk sugar, 1.0%; water, 13.0%. By weight butter should never contain more than 16% of water and should contain at least 80% of fat.
Owing to the conversion of the fat into fatty acids butter will, in the course of time, become acid, rancid and unfit for table use.
Oleomargarine is a product resembling butter. It is manufactured from animal fats and vegetable oils. It is not as desirable an article of diet as butter. It contains margarine fat and only .5% of the volatile fats, while butter fat contains about 8%.
Oleomargarine may be distinguished from butter by boiling. Butter boils more quietly and a foam is formed on top, while oleomargarine sputters much like oil mixed with water and there is little or no foam produced.