EXPERIMENT STATION BULLETINS 209 



of tlie pea-iod of lactation was taken for the experiment. There were seven days' 



trial of each methou, and the days upon which the ditferent methods were tried 



so alternated that the advance in the period of lactation should not affect the 



results. The amounts of milk used in the different trials not being the same, the 



results may be more easily compared if the amount of butter from a hundred 



pounds of milk be given: 



libs, of Butter from 

 100 lbs. of milk. 



Shallow ]ians 4.r> 



Deep setting 4.9 



Separator 5.5 



The difference in favor of the deep setting over shallow pans is slight. The 

 separator again shows a good gain over both the other methods. Nearly twenty 

 per cent more butter was obtained by tJie separator than by either of the other 

 methods. 



Dilution method.— There have recently been put upon the market so-called cream 

 separators, consisting simply of deep cans in which it is directed that the milk be 

 mixed with a certain amount of water and allowed to stand from two to twenty- 

 four hours, at the end of which time it is claimed that the cream will have separated 

 completely from the milk. There is a faucet at the bottom of the can for draw- 

 ing off the skim milk, and a strip of glass extending from the top to the bottom of 

 the can allows thi^ operator to see that the skim milk is all draAvn off. The claims 

 for efficiency in this apparatus are based upon the theory that by the addition of 

 water to the milk the per cent of solids not fat, and therefore the viscosity of the milk 

 is so reduced that, upon standing-, the cream will separate itself completely from the 

 rest of the mixture in a very short time. In a two weeks' trial of a can of this sort 

 known as the "Wlieeler- Cream Separator," in Avhicli about fort.v pounds of milk 

 were diluted with the same amount of water at sixty degrees, and allowed to stand 

 for twenty-four hours, the average loss of butter fat was equivalent to seven- 

 tenths of one per cent (.7) of undiluted skim milk. Not only was the loss excessive, 

 but the skim milk thus diluted with so much water could not be fed to advantage, 

 and the cream soured rapidly. 



HANDLING CREAM. 



Nolhing contributes more to sncr-oss in butter making tlian the proper care of 

 cream. Creamery men are coming to understand this; too many dairymen do not. 

 Proper care of cream alone will not give us good butter, but good butter cannot be 

 made from cream not properly handled. Good cream cannot come from bad milk. 

 The care of the milk, then, ds most important, as the history of the cream begins 

 with the history of the milk. The change in milk and cream which we call sour- 

 ing is due to the presence and the growth of minute organisms or germs, called 

 bacteria. Any substance or thing which is perfectly free from all forms of germ 

 life we can sterile. 



Germs, however, find their way into the milk duct of the teat and, even 

 though ihe bulk of the milk as it leaves the udder of the cow is free from germs, 

 the first few draughts are loaded with them. If it were possible to avoid this con- 

 tamination of the whole milk and to get the milk from the udder of the cow into 

 sterile vessels without contact with the air, we would not be bothered with sour 

 milk or cream. But, as it is, these minute forms of life are everywhere present. We 

 cannot prevent their presence, so we-must adapt ourselves to circumstances and con- 

 trol, in so far as we can, their growth. To properly care for cream is to handle it 

 in such a way that this growth is controlled. 



There are liable to be in the atmosphere of the barn different forms of germ 

 life, each producing, its characteristic result if it is allowed to develop in the milk 

 or cream_ There are numerous forms, the result of the growth of which is simply 

 to sour the milk; others cause a slimy condition; some produce a gas w^hich is 

 especially troublesome to the cheese maker; some give a bitter taste to the milk; 

 others form different pigments, imparting a blue or red color to the milk, as the 

 case may be, and the presence of still others is made manifest by oft"ensive odors. 

 All of these forms do not thrive best under the same conditions. Some require 

 high tempera tiires for their development; others require low; some require air; 

 others do not. The form which finds itself in a ma.iority usually develops itself at 

 the expense of othei's. holding them in check if the conditions are favorable, by its 

 27 



