Foaming Principles of Ingredients: Heavy Cream

Besides using the freshest possible heavy cream, it is crucial to always keep it very cold (at least 4°C / 39°F or colder, without freezing). This includes the final stage when the heavy cream is actually whipped, or otherwise it will lose its volume. Air is incorporated through whipping, either by hand using a whisk or using a mixer with the whip attachment. As the air is incorporated, the fat molecules (protein) latch on to the interface (or surface) of the bubble. First, the whipping motion physically destabilizes the fat molecules by breaking them down. These broken-down particles either cling to an air bubble’s surface or to other broken-down fat molecules, thus creating an even, stable network where the bubbles will not float to the top. These fat molecules reinforce the bubble’s surface because they surround it completely, trapping the bubbles. However, excessive whipping will force the fat molecules to continue to gather, forming large clusters of fat that are not capable of clinging to the air bubbles any further, so they escape and the mixture loses volume. With continued whipping, the congealed fat clumps will continue to separate out of the mixture; in a nutshell, this is how butter is made.