2 Testing Milk and Us Products. 



in diameter, one inch high, or 113 cubic inches. This 

 quantity of cream was supposed to make a pound of but- 

 ter, but cream from different sources, or even from the 

 same sources at different times, varies greatly in butter- 

 producing capacity, as will be shown under the subject 

 of cream testing (210 1 ). The system of paying for the 

 number of creamery inches delivered could not there- 

 fore long give satisfaction. 



The proposition to take out a small portion, a pint or 

 half a pint, of the cream furnished by each patron, and 

 determine the amount of butter which these samples 

 would make on being churned in so-called test churns, 

 found but a very limited acceptance, on account of the 

 labor involved and the difficulty of producing a first-class 

 article from all the small batches of butter thus obtained. 



2. The introduction of the so-called oil test churn in 

 creameries which followed the creamery-inch system, 

 marked a decided step in advance, and it soon came into 

 general use in gathered -cream factories (203). In this 

 test, glass tubes of about f inch internal diameter and 

 nine inches long, are filled with cream to a depth of five 

 inches, and the cream churned; the tubes are then placed 

 in hot water, and the column of melted butter formed at 

 the top is read off by means of a scale showing the num- 

 ber of pounds of butter per creamery inch corresponding 

 to different depths of melted butter. While the oil test 

 is capable of showing the difference between good and 

 poor cream, it can not make strictly accurate distinctions 

 between different grades of good and of poor cream 2 . As 



1 Refers to paragraph numbers. 



2 Wisconsin Experiment Station Bulletin 12. 



