110 Thirty-Sixth Annual Report of the 



During Prof. Decker's talk, he passed among" the audience 

 in test tubes and spoons, samples of melted first class butter, 

 melted oleomargarine and melted renovated butter. 



DISCUSSION. 



A Member: — What temperature would you recommend for 

 separating milk? 



Prof. Decker: — 150° F. is better than 90° ; but as separators 

 are usually operated in factories, 85° to 90° F. It is better with 

 our small separators to separate the milk just as soon as pos- 

 sible after it is drawn from the cow's udder. Milk separates bet- 

 ter at 90° to 95° F. than at lower temperatures because the fat 

 flows easier. As you lower the temperature of the milk serum 

 it is harder for the fat globules to move through it. It you warm 

 it up, the milk serum is more plastic and the fat globules will 

 pass through easier. If the milk is flowing rapidly through the 

 separator at 60° to 70° F. the fat globules are impeded in the 

 passage and do not get all separated. The operator has the 

 penalty in terms of the butter fat that he loses. 



A Member : — At what temperature would you churn ? 

 Prof. Decker : — To answer this question aright one needs 

 to understand the complexity of the laws which are called into 

 action. It depends upon the composition of the butter fat, on the 

 relative proportion of the nine dififerent oils. It may vary from 

 as low as 50° F. to as high as 60° F. according to circum- 

 stances as indicated in the text of my address. 

 A Member: — Would you churn at 62°? 

 Prof. Decker: — Possibly, particularly if the cream is thin. 

 Don't get cream too thin. Thick separator cream will churn 

 better than gravity cream, because the latter carries but 15 to 

 25 percent of fat. It is a thin cream. If cream is so thin that 

 you have to churn at a high temperature the butter comes very 

 soft and you are liable to injure its grain; it looks greasy and 

 mussy and it sells for less. You pay the penalty of your lack 

 of knowledge. To churn luider the best conditions cream should 

 carry 35 percent fat ; and then you can churn at a lower tem- 

 perature and get a harder and better butter which the butter- 

 milk will leave more completely. And you have more skimmilk 

 too. I take it that you are sending a good deal of relatively thin 

 cream to the gathered cream factories. Perhaps you think you 

 are going to get a little more money if you have a considerable 

 body of thin cream. This is not the fact. There arc three 

 reasons why thin cream is not as desirable. It contains more 



