Folding

When a recipe calls for folding, this means the act of gently mixing two parts of a batter together—no fast stirring, no whisking. The best way to do it is to use a rubber or silicone spatula and concentrate on turning the bottom part of the batter (often the heavier part) into the top part of the batter (often the lighter part) by scraping the sides of the bowl, then sweeping and twisting inward.