124 PRACTICAL DAIRY BACTERIOLOGY 



and thoroughly scrubbed; after this a second rinsing in hot 

 water is extremely desirable in order that the milk pail shall 

 be cleaned in fair condition. After washing they should be 

 placed inverted in the sun until used again. They should not 

 be tightly closed. Such a washing as this is about all that they 

 can receive upon an ordinary farm, but this is not enough to 

 sterilize them. 



There is, indeed, no means by which the farmer can so thor- 

 oughly wash his milk cans as to get rid of all bacteria. Every 

 creamery, cheese factory or separating station should under- 

 stand this and appreciate that a satisfactory washing can be 

 accomplished only where there is a supply of steam. Hence, 

 no creamery should depend upon the farmer to wash milk cans. 

 Where a supply of steam is to be had a sterilization must follow 

 the washing, but it should be different from that frequently 

 seen. The common procedure is to place the can for a few 

 seconds over a jet of exhaust steam, and after a short time to 

 remove it that it may be replaced by a second. The steam used 

 under these conditions hardly heats the can hot enough to kill 

 any bacteria, and while cans thus steamed are certainly some- 

 what more free from them than those not thus treated, the 

 impression of the dairyman that he has thoroughly cleaned 

 his cans of bacteria is incorrect. The only method by which 

 milk vessels can be absolutely freed from bacteria is by thorough 

 sterilization. This can be done by steam if the cans be 

 placed in a steam chamber built for the purpose, and the 

 steam turned on and left to act upon the cans for an hour 

 or so. In no other way can absolute sterilization be ac- 

 complished. Washing with hot water is better than with cold, 

 washing with sal-soda is better than without it, subjecting them 

 to a jet of exhaust steam is better than simple washing, and 

 sterilizing in a steam chest is better than all. Each dairyman 

 should adopt as thorough cleaning as is practicable. 



In washing dairy utensils special attention should be given 



