When eggs are the central ingredient in baked goods, handle them with care
Now that you know medium peaks are the way to go for soft, springy sponge cake, let's review some of the other important factors to keep in mind with this delectable treat. If you're making sponge cake to craft a homemade strawberry shortcake, how you whip the eggs isn't the only component worth remembering.
Ideally, you'll want to start the process with room-temperature eggs, so make sure you set them on the counter for roughly 30 minutes before whipping. Whip the eggs in a clean bowl with no bits of egg yolk or residual oil from your last cooking ventures, as those minor extras can impact the egg whites' development. Beyond whipping the egg whites until medium peaks form, how you combine the additional ingredients into the cake batter matters more than you might guess. To maintain their structural integrity, add the whipped egg whites gently so you don't risk losing the precious air you added during the mixing process.
If you're worried about maintaining the egg whites' form, add a small amount of cream of tartar to the raw egg whites before whipping them. Cream of tartar works to balance the consistency of aerated egg whites so that they maintain their structured shape. Taking extra care of those precious eggs will not only make for a lighter, chewier sponge cake, but you'll also have an ideal base to make a sweet, juicy platter of strawberry shortcake.