Rinse the grapes, cut them in half and remove the seeds. Squeeze the lemon and swell the gelatine in the cold water for five minutes. Place the white grape juice in a casserole dish with the sugar and the juice of one lemon and heat. Add the gelatine and let it melt in the liquid without making it too thick. Cool the jelly to hand heat while stirring. Divide the grape halves evenly among 4 ramekins or small dessert bowls. Leave a few blue grapes for garnish. Pour the jelly over the top and chill in the refrigerator for the final time. Heat the milk and remove from the heat. Let the raw marzipan melt in the milk and then whisk it. If the marzipan foam is too viscous for you, it can be thinned with a little milk. Before serving, hold the jelly in hot water for a few seconds to make it easier to turn out. Leave the jelly to cool for 5 minutes.
Spread the marzipan foam evenly in the center of a plate, then arrange the grape jelly on the foam, decorate with the remaining blue grapes. Finally, sprinkle the edge of the plate with a tiny bit of powdered sugar.
Egg white : 9 gram