How does a cream separator remove fat from milk?

A cream separator removes fat from milk by utilizing a high-speed centrifuge to exploit the difference in density between skim milk and cream.12

The process works as follows:

• Centrifugal Force: Whole milk enters a rapidly revolving bowl—spinning at approximately 6,000 to 8,000 revolutions per minute—which generates intense centrifugal force.12
• Separation: Because skim milk is denser than cream, the centrifugal force throws the heavier skim milk toward the outer wall of the bowl, where it is led off through an opening.12
• Collection: The lighter cream is forced toward the center of the bowl and is piped off separately.12

In addition to separating fat, the machine acts as a clarifier. Heavier particles, such as sediment, somatic cells, and some bacteria, are forced to the outside and collected as "separator sludge," which is then discharged. Most modern separators are computer-controlled, allowing for precise regulation of the final fat content in the milk.12