Fold egg whites

Egg whites are folded into a base sauce when lightness and structure are required.
Once the base and whites are ready, mix a small amount of the whites into the base, this is tempering the base ready for the whites.
Next place 1/3 of the whites into bowl with the base, using a large spoon or spatula, gently work the whites into the base using a figure of 8 motion, or a gentle movement that brings the contents of the bottom the bowl to the top, slowly enveloping the whites, once the first batch is almost mixed in add another 1/3.
Continue until all the whites are folded in.