Rinse the rose petals and drain thoroughly. Make sure to remove the bitter white stalks from the petals. Whip the egg whites until frothy.
Dip the rose petals in the egg white, sprinkle on both sides with the sugar, then place on a baking sheet lined with parchment paper. Place in a 50-60°C (approximately 125-140°F) oven, and let dry for 2-3 hours.
Layer the rose petals and parchment paper in a tin or in a jar. Seal tightly until consumed.