Bacteria in Butter- Making. 



139 



it is necessary that the starter should be handled in a 

 way so as to prevent the introduction of foreign bacteria 

 as far as this is possible. The following points should 

 be kept in mind in manipulating the starter: 



FIG. 32. Apparatus for sterilizing and propagating the starter 



1. If a pure-culture ferment is used, see that it is fresh 

 and that the seal has not been disturbed. 



2. If a home-made starter is employed, use the great- 



