When you buy cream for whipping, you have two options: heavy cream (also called heavy whipping cream) and whipping cream (also called light whipping cream). Their chief distinction is fat. Per the U.S. Food and Drug Administration, heavy cream must be at least 36 percent fat, while whipping cream must be at least 30 percent fat but less than 36 percent fat. That didn't sound like a big difference to us, so we decided to whip the two types and compare the results. Since creams can also vary in how they're processed—most are ultra-pasteurized at a high temperature to prolong shelf life but some are simply pasteurized—we wanted to compare those differences as well.