Folding Technique for Light Sponge

Proper folding technique is essential for maintaining the airy texture that makes Swiss rolls rollable. After whipping eggs and sugar to pale ribbons, flour must be folded in gently using a large metal spoon or rubber spatula. Use a cutting and folding motion - cut down through the center, sweep along the bottom, and fold up and over. Rotate the bowl quarter-turns as you work. The goal is to incorporate flour while preserving as much air as possible. Over-mixing deflates the eggs, creating a dense, heavy sponge that won't roll without cracking. Stop folding as soon as no flour streaks remain. The batter should flow like thick cream, not thick paste.