7o6 



Journal of Agricidtiire. Vict aria. 



[lo Oct.. i9Tt_ 



The Rennet Test. 



Heat a small quantity of milk in a dipper placed in hot water, raising: 

 the temperature to 84 deg. or 86 dig. Take a 4-oz. glass measure of 

 the milk and pour into an enamel mug, place in it a small chip or cork, 

 pour in one drachm of rennet, and stir vigorously for 10 seconds with a 

 clean teaspoon or a glass rod; then withdraw the spoon and watch when 

 the chip stops. If the chip stops quickly, the milk is over-ripe. 



The Acidimeter or Titration Test. 



The acidimeter or titration test is based on the fact that one cubic 



centimetre of decinormal solution of 

 caustic soda will neutralize .009 gramme 

 of lactic acid. 



To make the test, put 10 c.c. of the 

 l!(|uid to be tested in a white cup, 

 and add two drops of phenol plithalein 

 solution, which acts as an indicator of 

 the point that neutralization of the acid 

 by the soda takes place 1)V the produc- 

 tion of a pale pink colouration. Fill a 

 burette graded in one-tenth of cubic 

 centimetres with the soda solution, but 

 not above the o mark. Note the point 

 at which the solution in the burette 

 stands ; then turn the tap, and allow 

 the solution to run gradually intO' the 

 milk, stirring with a glass rod all the 

 time. Each drop of the .solution pro- 

 duces a pink colour, but when stirred 

 it immediately disappears until the soda 

 solution neutralizes the. acid, when a. 

 permanent pink colouration is produced. 

 .^s soon as this point is reached note how 

 far the li(]uid has run down the burette;. 



and if it has dropped 22 spaces, equal to 2.2 c.c. The percentage of acid 



is calculated as follows : — 



2-2 X -009 X 100 = -lUS— the i)ercentige of l:u-tic add present. 

 10 



A quicker and simpler way of making the test is tO' take 9 c.c. of the 

 liquid to be tested, when the number of spaces of the soda solution used 

 will indicate the percentage of acid present. For instance, say. it takes^ 

 22 spaces to neutralize the acid, then — 



2-2 X -OOO X 100 =, -22 per cent, of ;u-i '. 



APPARATUS FOR ACIDIMETER TEST. 



The temperature of the milk does not influence the titration test. 



Various Stages of Manufacture. 

 Commercial Starter. — A good starter is the foundation of cheese- 

 making, as it is composed almost entirely of lactic acid bacteria ; and. iu' 

 adding it to the milk, millions of desirable germs are introduced and help 

 to crowd out the undesirable ones. Use from i to i ^ per cent, according; 

 to the sweetness of the milk. 



