It's a common belief that red velvet cake is just chocolate cake with red food coloring, but there's more nuance to the difference between these desserts. A vivid red color is the biggest defining trait of red velvet cake, but its taste and texture are also distinct from plain chocolate cake, thanks to natural cocoa and buttermilk.

Back in the day, red velvet cake was colored by using natural cocoa powder, a more acidic cocoa with higher levels of a pigment called anthocyanin, which would turn red when combined with buttermilk. Today, many recipes use food coloring to tint the cake, but still call for natural cocoa and buttermilk to define the cake's flavor.

Natural cocoa tastes more fruity and light than the rich Dutch cocoa used in most chocolate cakes, and natural cocoa's acidity also takes on a leavening property when combined with baking soda and buttermilk. This makes red velvet ever so slightly tarter and lighter than chocolate cake, as well as more fluffy and tall.