REFRIGERATION 527 



3. Cooling". — After screening the milk must be cooled. The 

 Copenhagen Milk Supply Company lay down as a standard that 

 immediately after being drawn from the udder and during all 

 seasons of the year, the milk must be cooled down with ice water 

 to 40" R, and that everj' contractor must be provided with a 

 Lawrence cooler obtainable from the Company. Thirty lbs. of 

 ice, making due allowance for water, must be kept in stock for 

 ever)' 100 lbs. of milk produced, calculated from the fortnightly 

 trial milkings. The Danske Maelke-Compagni of Frederiksberg, 

 near Copenhagen, also insists that the farms contributing milk 

 must have ice for cooling milk, and the milk must not reach the 

 establishment at a temperature above 10' C. (50"^ F.). 



One of the English Companies supplying pure milk has closely 

 followed the practice in Denmark, and laid down the following 

 regulation to be complied with by all farms contributing milk : 

 The milk shall be immediately (after milking) cooled down irre- 

 spective of weather or season of the year to 40" F., by passing it 

 over a cooling apparatus of approved pattern, kept cool with ice to 

 be provided by the farmer, and the milk shall be kept at that 

 temperature in the milk-cans provided by the Company until time 

 for it to be sent to the station. Should the Company not require 

 the farmer to use ice, the milk, after being strained through a fine 

 wire strainer covered with a clean woollen cloth, must be immedi- 

 ately cooled down, irrespective of weather or season of the year, to 

 within 4° of the temperature of the coolest water on the farm, by 

 passing it over a cooling apparatus of approved pattern, and the 

 milk shall be kept at that temperature in the milk-cans provided 

 by the Company until time for it to be sent to the station. 

 Where natural ice is used, at least 30 lbs. of ice shall be avail- 

 able for 100 lbs. (10 gallons) milk produced. In years when with 

 reasonable care on the part of the farmer, sufficient natural ice or 

 snow cannot be got, the Company shall deliver at the nearest 

 station such ice as the farmer may require, at the nominal price 

 of I2S. 6d. per ton. 



Ice is not necessary to cooling, as combined aerators and 

 coolers suitable for use with well water or ice water can be 



number of bacteria present worked out at over 43,000. The advantage of using 

 the narrow-mouthed pail with the object of excluding the bacteria, in this case, 

 was well shown by the fact, that whereas the milk drawn into the narrow-mouthed 

 vessel did not go sour until after being kept sixt>'-four hours, that milked into 

 the open pail — and subsequently found to contain 43,000 odd bacteria — went 

 soiu- in forty-seven hours. 



