This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
See also Foods.
An apparatus for determining cream in milk consists of a glass cylinder having a mark about half its height, and a second mark a little above the first. The milk is added up to the lower mark, and water up to the second. The amount of water thus added is about one-fourth the volume of the milk, and causes the cream to rise more quickly. The tube is graduated between the two marks in percentages of cream on the undiluted milk. A vertical blue strip in the side of the cylinder aids the reading of the meniscus.
To 10 parts of milk add 1 part of fuchsine sulphurous acid. Allow to stand 5 minutes, then add 2 parts of pure hydrochloric acid and shake. If formaldehyde is not present, the mixture remains yellowish white, while if present a blue-violet color is produced. This test will detect 1 grain of anhydrous formaldehyde in 1 quart of milk.
To malt milk, add the following:
Powdered malt...... 1 ounce
Powdered oat meal. .. 2 ounces
Sugar of milk........ 4 ounces
Roasted flour........ 1 pound
These are made from skimmed milk freed from casein, sugar and albumen, and resemble meat extracts. The milk is slightly acidulated with phosphoric or hydrochloric acid, and evaporated in vacuo to the consistency of thick syrup. During the crystallization of the sugar, the liquid is sterilized.