164 CITY MILK SUPPLY 



where rust shows. Badly rusted and dented tinware is properly 

 confiscated by boards of health. 



The trouble that the cleaner causes is in part due to his carelessness 

 and in part to his doing the work in the wrong way. Vigorous prodding 

 by some one in authority is the only cure for the shiftless washer. Proper 

 cleansing of milk vessels is effected by first rinsing them in cold or luke- 

 warm water to remove the milk after which they should be scrubbed with 

 a brush inside and out, in hot water and washing powder; then they should 

 be rinsed in clean hot water. If the cold rinse is omitted the hot water 

 will cause some constituents of the milk to stick tenaciously to the 

 utensils. 



Sterilization of milk utensils is generally effected by heat. The 

 effectiveness of the process depends on the degree of temperature and 

 the length of time it is applied. The use of water at less than boiling 

 temperature and hurrying the work unduly, makes the process a farce. 

 The smaller vessels and bottles can be thoroughly sterilized by boiling 

 them. The breakage of glassware need not be excessive if the bottles 

 and other dishes are first put in tepid water which is afterward brought 

 to a boil. Care should be taken to cool the glassware slowly, otherwise 

 it is apt to become brittle. In many small dairies and in all large plants 

 steam is available for sterilizing. It is used in several ways; it may be 

 turned into cold water to raise the temperature, or in the form of stream- 

 ing steam it may be played from a hose onto apparatus, or ejected from 

 stationary jets into cans and other tinware or turned into chambers of 

 various sorts containing utensils to be sterilized. Under pressure, steam 

 is most effective as a sterilizing agent and in large milk plants there are 

 huge sterilizing ovens for employing it in this way. There is no question 

 of the effectiveness of steam for sterilizing, when it is faithfully and 

 intelligently used. It gives a sense of security to see it freely employed 

 for this purpose in a milk plant or factory, but this feeling is often unwar- 

 ranted for very frequently the steam is not applied long enough to the 

 utensils to more than raise the temperature to the point where bacterial 

 multiplication is stimulated, or else it merely loosens the milk or bacterial 

 coating adherent to the utensils so that the next milk that is put in them 

 is heavily contaminated. Bacterial tests made some hours after cans 

 have been steamed often show how imperfect sterilization has been and 

 a foul odor indicative of bacterial decomposition is often plainly notice- 

 able when covers are removed at the farm, from cans washed and steamed 

 at the city milk plant or creamery. A device that will insure the exposure 

 of the utensils to the action of the steam jets for a fixed length of time is 

 needed. While with autoclaves, sterilizing is less likely to fail, the danger 

 still exists for if they are run carelessly the pressure required to sterilize 

 may not be reached. 



When tinware is sterilized by streaming steam it should be dried 



