Fat naturally exists in milk in little spheres or globules about 1/1500 of an inch diameter. When fat or oil is suspended in this way in a liquid it is said to be emulsified.

Experiment To Illustrate Emulsion

Shake some lime-water and linseed oil together in a bottle; hold the bottle still and observe the oil globules rise.

The fat globules, being lighter than the rest of the milk, tend to rise to the top as cream.

Making Butter

If cream be vigorously beaten or churned, the globules lose their shape and stick together, forming butter. Some of the casein clings to them. This should be washed out, as it decomposes easily. Butter is salted to protect it further from spoiling. It is usually packed in wooden tubs for market. Butter molded in "prints" for immediate table use is made less salt than tub butter. "Sweet" butter contains no salt and sells at a high price.

Milk from grass-fed cows makes yellow butter, but most butter comes so pale a color that it has to be colored for market. The coloring used is harmless. Good butter is firm, not crumbly, and yields little water when pressed.


A. Butter-making. - Put half a cupful of thick cream into a small bowl and beat it with a Dover egg-beater until it separates into buttermilk and specks of butter. Gather the butter into a lump, and after pressing out as much of the buttermilk as you can, wash the butter under a stream of cold water. Work with a wooden spoon to remove the water, and add a few grains of salt. Dip butter-spatters into hot water, then into cold, and with them roll the butter into a ball. (Plate VI, facing p. 90.) Use sweet or sour cream.

B. Test for butter. - Heat in separate dishes butter, butterine or oleomargarine, and renovated butter. Butter boils quietly, producing considerable foam. The others sputter, but foam little.

Butter is usually made from ripened cream; that is, cream carefully soured to obtain a flavor produced by certain bacteria. Renovated butter is made from rancid butter by a process which makes it wholesome. (See butterine, p. 215.)

Food Value Of Butter

Butter is one of the most whole-some as well as most delicious forms in which fat may be eaten. Is it a good fuel food? Why? (Chart 7, p. 217.) Do you need as much butter on your bread when you eat bacon for breakfast as when you eat lean meat ? For more about the food value and digestion of fat, see pp. 216, 218, and 370.

Whipped Cream

Cream, 1/2 pt. Powdered sugar, 2 tb.

Extract of vanilla, 1/4 to 1/2 t.

Whip it with a wire whisk or a Dover beater until stiff enough to hold its shape, beat in the sugar and vanilla, and keep in a cool place till served. In warm weather, set the bowl of cream in a pan of cracked ice while whipping it. Serve on hot chocolate, or as a sauce with desserts.