NEUTRALIZATION OF SOUR CREAM 151 



the purpose. They all refer to the use of a dilute solution 

 (usually a decinormal solution) of sodium hydroxide. Detailed 

 directions for these tests are recorded in the chapter on "Tests 

 and Analyses/' etc., Chapter XXII. If a decinormal solution of 

 sodium hydroxide, and an 18 c.c. pipette are used for measuring 

 the cream, each two-tenths cubic centimeter of alkali solution, as 

 shown on the graduation of the burette, represents .01 per cent 

 acid. Hence the number of c.c. alkali solution divided by 20 

 gives the correct per cent acid in the cream. Thus, if say 

 7.4 c.c. alkali solution is required to turn the cream pink the 



7 4 

 per cent acid is ' = .37%. 



Choice of Neutralizes There is a variety of neutralizers 

 that have been and are being used for the purpose of reducing 

 the acidity in cream intended for buttermaking. 



Neutralizers used for the purpose of reducing acidity, must 

 have alkaline properties, they must be alkalies, or alkaline 

 earths, or their carbonates. An alkali is a substance that neu- 

 tralizes acids, forming salts, and that saponifies fats. The 

 most common neutralizers that have found application in the 

 creamery are the carbonates of sodium (soda ash), and of calci- 

 um (chalk), the bicarbonate of soda (baking soda), the hydrate 

 of soda (soda lye), and of calcium (lime water and milk of 

 lime), and the oxide of calcium and of magnesium (quick lime 

 and magnesia lime). 



The chief advantages of carbonate and bicarbonate of soda 

 are that they are readily soluble and, therefore, can be easily 

 made up into solutions of desired strength. This is a distinct 

 advantage. Calcium carbonate, on the other hand, is very in- 

 soluble and slow of action, which renders its use unsuitable 

 for this purpose. All carbonates above mentioned liberate car- 

 bondioxide gas when they are added to the sour cream. This 

 fact is claimed by some to be greatly in favor of their use, 

 as neutralizers. The claim is that the carbondioxide gas per- 

 culating upward in and escaping from the cream, mechanically 

 carries with it volatile gases having undesirable odors and 

 thereby removes from the cream, objectionable odors and 

 flavors. 



