116 Testing Milk and Its Products. 



before it is ready to churn, a 50 cc. cylinderful of tablet 

 solution of this strength will not be sufficient to make a 

 test of cream containing over .5 per cent of acid, although 

 it is enough for testing the cream up to this point during 

 the ripening process. The acid-testing outfit should 

 therefore contain a 100 cc. graduated cylinder, instead 

 of one of 50 cc. capacity, so that cream of any amount of 

 acidity up to 1 per cent, can be tested. A tablet solution 

 of the strength given has not only the advantage over 

 the solution previously recommended (5 tablets to 50 cc. 

 of water) 1 of showing the per cent, of acidity directly, 

 without tables or calculations, but being weaker, the 

 unavoidable errors of determination are decreased by 

 its use. 



Equally accurate results may be obtained by using 

 solutions made up according to method a or method 6, 

 explained in the preceding. The latter method (17.6 cc. 

 cream, 5 tablets per 97 cc. of water) has, however, the 

 advantage in point of economy of apparatus, since a 

 17.6 cc. pipette is found in creameries and dairies with 

 the Babcock test outfit and is therefore most likely 

 already available for use in testing the acidity of cream. 

 This method is therefore considered preferable and 

 referred to as 



137. The standard solution. The preparation of this 

 solution is as follows: Five tablets are placed in the 

 100 cc. cylinder which is filled to the 97 cc. mark with 

 clean soft water 2 . The cylinder is tightly corked, shaken 



i_ Illinois experiment station, bulletin No. 32; Wisconsin experiment 

 station, bulletin No. 52. 



2 Condensed steam or rain water should be used, and not hard water 

 or alkali water, since the impurities in these affect the strength of the 

 tablet solution. 



