In a bowl or a jar combine the raspberries and sugar and stir well, cover and set aside in the refrigerator for 2 days. Stir the sugar and raspberries occasionally. After 2 days add the vinegar, stir, return to the refrigerator for another 2 to 3 days. Strain the fruit from the mixture and transfer the shrub to bottles or jars. It will last for up to 1 month in the refrigerator.