EXPERIMENT STATION BULLETINS 205 



well ventilated cellar makes an excellent place for setting milk, but the kitchen 

 or pantry should never be used. Milk is peculiarly sMisceptible to bad odors, and 

 really tine butter cannot be made from milk set in an impure atmosphere. 



Because of the relatively lai'ge amount of surface exposed, the cream upon milk 

 set in shallow pans is liable to become hard through excessive evaporation unless 

 some means are taken to prevent it. The hard cream upon the pan becomes hard 

 lumps in the churn and these lumps, not takino- color with the rest, appear as white 

 specks in the butter. We have found that in practice it is a good plan to cover the 

 pan with a single thickness of cheese cloth. 



Not only is it essential that the air of the milk room should be pure and sweet, 

 but it is equally important that the temperature should be under control. The 

 lower the temperature of the room in which the milk is set the less will be the 

 loss of the butter fat in the skim milk. In setting milk in deep cans we desire 

 a temperature as low as 40 deg.rees Fah. If we could have our milk rooms at this 

 temperature the separation of the cream would be much more complete than when 

 set at ordinary room temperatures. 



The difference between the specific gravity of the cream and that of the milk is 

 made greater by cooling. The lower the temperature to which the milk is cooled, 

 and tJie more rapidly it is cooled to that temperature, the more readily does the 

 separation of the milk and cream take place. 



By the use of the separator the cream may be taken from the milk immediately 

 after milking. If the cold deep setting method of separation is used, the milk 

 may be skimmed as soon as the cream has all risen, which, under the best condi- 

 tions, will be at the end of about twelve hours; but in the case of shallow pans 

 the time of skimming must be regulated by the condition of the ci-eam. This will 

 vary under different surroundings. Cream must have a certain degree of thickness 

 in order to be skimmed Avithout too great a loss from the almost unavoidable mixing 

 ot the milk and the cream during skimming. Some prefer to wait until the milk is 

 sour. Skimming at the end of either twelve, tAventy-four or thirty-six hours 

 generally makes a most convenient arrangement of the work, and we have found 

 it most satisfactory, all things comsidered, to skim at the end of twenty-four 'hours. 

 The loss of butter fat would perhaps be a trifle less if the milk were allowed to 

 stand longer and the cream were to become thicker, but the quality of the latter 

 would not be as good. Skimming the milk while the cream is yet sweet is to be 

 especially recommended if the product of the dairy is small and the cream has to be 

 saved for some days in order to get a churning. 



-At best, the loss of butter fat in the skim milk from shallow pans is excessive. 

 We have found that in the fall, when probably half of the cows in the herd were 

 "«trippers," and the milk was set for twenty-four hours in a room which varied in 

 temperature from 57 to 62 degrees Fah., Avith an avera.ge between 58 and 59 degrees 

 Fah., the butter fat in the skim milk was .H6 per cent. A similar trial conducted 

 for twenty-one days in the spring showed the same result. Here was a loss of 

 practically one-fifth of all the butter fat. Excessive as this may seem, it is con- 

 siderably below the average Avaste on farms Avhere this method of setting milk is 

 practiced. The average per cent of butter fat in the skim milk from shallow pans 

 on seventeen farms near the college Avas found to be just a trifle under 1 per cent 

 (.98 per cent). In seven cases it was aboA'e this figure, aA'era.ging 1.5 per cent, while 

 In the ten cases where the loss was less than 1 per cent the average was .63 per 

 cent. 



Void deep setting. — By cold deep setting is meant that system in common use 

 where the milk is allowed to stand in some form of deep can set or submerged in 

 cold water. The system has its advantages over the shallow-pan method. The 

 tank of cold water AAith the enclosed cans of milk does not take up much room, thus 

 making it easy to provide a place for it where the air is pure and the ventilation 

 good. On account of the cans being covered, the cream is never hardened on the 

 surface, as is liable to be the case Avith shallow-pan cream. It is not necessary for 

 the milk to stand more than twenty-four hours, and, remaining as it does at a low 

 temperature, both milk and cream are sweet at the time of skimming. The ripen- 

 ing of the cream may then be conti-olled, and the skim milk fed sweet to calves or 

 pigs. Properly handled, there is less loss of fat in the skim milk than with shallow 

 pans. The apparatus may consist simjdy of shot-gun cans set in kei-osene barrels 

 sawed off to be of proper depth, a conical dipper being used for skimming, or the 

 more convenient and more etficient and at the same time more expensive cabinet 



