With this refreshing cocktail, a twist on the classic Bramble, you can now drink your blackberries. Process your fresh blackberries in a blender until smooth. Pour the mixture through a fine mesh strainer (to remove any pulp or seeds) into a jar with a tight-fitting lid. If you have any canning jars in the cupboard, this is the perfect time to use one. Add pisco, which is a South American grape brandy popular in Peru and Chile.