Thaw raspberries (if frozen), set 100g aside for decoration.
Soak the gelatine in cold water. Boil the mineral water with sugar once, dissolve the squeezed gelatine in it and puree the raspberries with it. Strain the mixture through a sieve, mix with the yoghurt and refrigerate for 15 minutes. Whip the cream until stiff, stir into the cream, fill into 4 glasses and chill for another hour.
Serve decorated with the retained raspberries and mint.