MILK-PLANT OPERATION. 
27 
ized with steam. The cleaning and sterilization of the milk piping 
and pumps are often neglected. While it is sometimes possible to 
clean the pipes satisfactorily by means of pumping solutions through 
them, followed by thorough rinsing and steaming, usually this is not 
sufficient. It is much more satisfactory to take down and clean the 
piping thoroughly every day. At many plants complaints are re- 
ceived about the quality of the milk, that it turns sour quickly, etc., 
and the operator is often at a loss to know what the trouble is, as he 
has been careful with the temperatures used in pasteurization and 
the milk is kept cold after pasteurization. Often the trouble is 
found to be with the milk pipes, joints, and pumps. If the pipes are 
not thoroughly cleaned and sterilized each day, filth and dirt will 
soon collect at joints and elsewhere, and the milk passing through 
Fig. 19.— Milk piping after being disconnected, washed, and steamed. 
such apparatus will be badly contaminated and will be of very poor 
quality. 
Great care should be taken in cleaning the pasteurizing outfit. 
This should be rinsed immediately after using, and then thoroughly 
cleaned and finally rinsed and steamed. Small brushes must be used 
to get at the parts of this apparatus and no effort should be spared 
in keeping the pasteurizer clean. After the work with the milk has 
been finished, water should be run through the apparatus, followed 
by water to which washing powder has been added, and a thorough 
cleaning with brush, then rinsing and steaming. 
Much attention should be paid to keeping flies out during the warm 
season. All windows and doors should be well screened. Revolving 
fans placed near and blowing toward the door, which should open 
