Rinse berries in a sieve. Strip currants from the panicles.
Place in a large enough bowl with the blackberries. Add the sugar, stir in. Leave to infuse for half an hour.
Peel the bananas, cut into slices. Mix loosely with the brandy in a second baking bowl and let sit for 15 min.
Pour the berry mixture and the bananas into a punch bowl. Pour in the white wine, stir and add the sparkling wine.
If desired, add plucked leaves of lemon balm.