Department of Dairy Industry. 541 



Very few of the cheese-makers and butter-makers are able to make and 

 standardize their own solutions to be used in such tests. For this reason 

 a concentrated solution is advised, 50 c. c. of which is sufficient to make 

 23DO c. c. of a i/io normal alkaline solution. This small amount is not 

 costly and can be sent through the mails for a few cents. When tightly 

 corked this solution will retain its strength indefinitely, so that it can be 

 kept in stock in almost any place. 



The indicator is made by dissolving 5 ^rams of dry phenolphthalein in 

 100 c. c. of 50'^ alcohol. The commercial alcohol, which is about 95^ 

 pure, can be used by diluting 50 c. c. of it with 50 c. c. of water. It can 

 be purchased ready for use from dairy supply houses. 



The preparation and successful handling of a good commercial starter 

 for use in cheese-making or butter-making depends very largely upon 

 the amount of acid allowed to develop in the starter from day to day. 

 Uniformity is one of the great factors of success in dairy work, especially 

 in the manufacturing department, and one need only know this to appre- 

 ciate the value of any simple test that will enable him to measure the 

 acid in his product as closely as i/ioo of one per cent. 



By the use of such a test one is guided in controlling temperature and 

 bacterial life associated with the manufacturing process, so that if the 

 raw material reaches the cheese-maker or butter-maker in good condition 

 there is no reason why he should not be able to turn out butter or cheese 

 of uniform quality each day. 



DIRECTIONS FOR USING THE ACIDIMETER 



How to set lip the test. — In a convenient place erect a small shelf to 

 support the large bottle. Cut a notch in the front or back of the shelf to 

 allow the brass-pipe to pass through. 



Then add the contents of the small bottle of alkali to the large bottle, 

 rinsing the small bottle several times, and each time pouring the rinsings 

 into the large bottle. Then add soft water to the large bottle until the 

 level reaches the mark filed on the bottle. You will then have 2300 c. c. 

 of a i/io normal alkaline solution. 



The small wash-bottle attached to the neck of the larger one should be 

 half filled with this solution. Then the rubber and glass connections are 

 made between the two bottles. 



The burette-holder is fastened underneath the shelf so that the alkali 

 from the large bottle can enter it. The dropper bottle is then filled with 

 indicator. 



To use the test. — Measure with a pipette 9 grams of the substance 



