Fold

Folding is a gentle mixing technique used to combine a light, airy ingredient with a heavier one without deflating the air that has been beaten in. Instead of stirring, which knocks out the bubbles, you use a spatula to cut down through the center of the mixture, sweep it across the bottom of the bowl, and lift it up and over the top, rotating the bowl a little between strokes and repeating until the mixture is just combined. The motion is slow, deliberate, and minimal.

Folding is essential when adding whipped egg whites or whipped cream into a batter, as with souffles, sponge cakes, mousses, and meringues, where preserving volume is what keeps the final result light. The tip that matters most is to stop as soon as the streaks disappear, since every extra stroke costs you lift. Using a wide, flexible spatula and a light hand lets you incorporate the ingredients with the fewest possible motions.