Shrubs were popular in Colonial times where they used this method to preserve fresh berries for the next year. Combine 2 cups of blackberries with 2 cups of sugar, mashing a bit to get the fruit juices flowing. Cover with plastic wrap and put into the fridge for a couple of days, stirring occasionally. After a few days, strain the berry mixture into another bowl and whisk in 1 cup of red wine vinegar. Pour mixture into a bottle and keep in the fridge for up to a year. Add this to club soda for an amazing non-alcoholic drink or use in your favorite mixed drink for a new twist.