Bring sugar and 200 ml water to the boil in a saucepan and simmer for approx. 2 mins. Leave the syrup to cool. Halve and squeeze the lemon and grapefruit (approx. 200 ml of juice). Pour the juice through a sieve and mix with 100 ml Rotkäppchen Demi Sec.
Beat the egg whites with a whisk until stiff. Mix the syrup and sparkling wine mixture together in a bowl. Carefully fold in the egg whites. Freeze the mixture for several hours, preferably overnight. Stir vigorously every 30 minutes for the first four hours.
Remove the sorbet in balls using an ice cream scoop. Put a ball of sorbet in each champagne glass. Top up with the remaining Rotkäppchen Demi Sec and serve immediately.
Preparation time approx. 30 minutes. Freezing time approx. 12 hours.
Approx. 540 kJ, 130 kcal per portion. P 1 g, F 0 g, CH 28 g
Image notation Rotkäppchen by Food & Foto Experts