Page:The story of milk.djvu/80

 It has been attempted to make the brine freezers continuous, the cream mixture being fed into the machine at one end and discharged frozen at the other. But this system has not so far been successful, and intermittent or batch freezers are most practical yet both for hand and for power.

Power brine freezer

Rich material, frozen in a good machine, whether intermittent or continuous, will expand from 50% to 100%, and the original material should not fill the freezer-can more than half full.

The manufacture of ice cream has been the subject of study and experiments for years in the Dairy Department of the Agricultural College at Ames, Iowa, where Professor M. Mortensen has worked out a comprehensive classification from which any manufacturer