MILK. 385 



circumstances ; it succeeds best between 55 and 60" F. So that, 

 in summer, a cool place, and in winter a warm place, is chosen for 

 the operation. There is no absorption of oxygen during the process 

 of churning, as was once supposed ; the operation succeeds perform- 

 ed in vacuo, and with the churn filled with carbonic acid or hydro- 

 gen gas. 



On being taken out of the churn, the butter is kneaded and press- 

 ed, and even washed under fair water, to free it as much as possible 

 from the buttermilk and curd which it always contains, and to the 

 presence of which must be ascribed the speedy alteration which 

 butter undergoes in warm weather. To preserve fresh butter it is 

 absolutely necessary to melt it, in order to get rid of all moisture, 

 and at the same time to separate the caseous portion. This is the 

 process employed to keep fresh butter in all the warmer countries 

 of the world. In some districts of the continent, it is also had re- 

 course to with the same view. The butter is thrown into a clean 

 cast-iron pot, and fire is applied. By and by the melted mass enters 

 into violent ebullition, w'hich is owing to the disengagement of wa- 

 tery vapor ; it is stiried continually to favor the escape of the steam, 

 and the fire is moderated. When all ebullition has ceased, the fire 

 is withdrawn, and the melted butter is run upon a strainer, by which 

 all the curd is retained. M. Clouet has proposed to clarify butter 

 by melting it at a temperature between 120° and 140^ F., and keep- 

 ing it so long melted as to dissipate the water and secure the depo- 

 sition of the cheesy matter, after which the clear melted butter 

 would be decanted. I doubt whether by this means the water could 

 be sufficiently got rid of, a very important condition in connection 

 with the keeping of butter, though certainly all the caseum would 

 be deposited. 



The moisture and curd contained in fresh butter may amount to- 

 gether to about 18 per cent. ; at least we find that we lose about 18 

 lbs. upon every 100 lbs. weight of butter which we melt at Bechel- 

 bronn. 



The information which we have on the produce in butter and 

 cheese, from different samples of milk, is very discordant, so that 

 I prefer giving the results of a single experiment made under my 

 own eyes. From 100 lbs. weight of milk, we obtained : 



Cream 15.60 lbs. 



White curd cheese 8.93 " 



Whey 75.47 " 



100.00 



The 15.60 lbs. of cream yielded by churning: 



3.3 lbs. butter, or 21.2 per cent., and 

 12.27 " buttermilk. 



The reckoning with reference to 100 lbs. of milk consequently 

 stands thus : 



Cheese 8.93 



Butter 3.33 



Buttermilk 12.27 



Whey 75.47 



100.0 



33 



