In the pasteurization process, the milk is heated to over 160 degrees F, kept there for 15 seconds and then rapidly cooled to 35 degrees F. This eliminates any microorganisms that could cause diseases or accelerate spoilage. The graphs on the outside of the machine make a record of this process.

The homogenizing tank makes the milk consistently smooth. Under lots of pressure, it whips any butterfat into very tiny particles that are too small to separate from the milk.