For the Alt Bier Bowle, first rinse ripe strawberries briefly under running water, dry and remove the stalk tips. Halve or quarter larger strawberries and leave small strawberries whole. Put the strawberries in a bowl and mix with the sugar. First pour 1 bottle of well chilled Alt beer over the strawberries and let the Alt beer bowl stand for about 1 hour. Shortly before serving, pour in a second bottle of cold Alt beer and add 1/2 bottle of ice-cold sparkling wine to the Alt beer punchle.