Asked by: Anonymous
Cream is the fatty layer that naturally separates at the top of whole milk. It contains water, milk sugars, a small amount of protein and lots of fat.
When cream is whipped, small air bubbles become trapped in the mixture. Meanwhile, the fat, which exists as fairly stable droplets inside a cream carton, begins to break up when whizzed around with a whisk. As the droplets break apart, molecules of fat rearrange themselves around the air bubbles, preventing them from escaping. This causes the cream to increase in volume until it becomes stiff enough to spread over cakes and pies.