Cook the syrup. Pour water over the sugar, put it on the stove and let it boil. Stir the syrup for the next 5 minutes, then remove it from the heat, add the berries, stir and put it in the refrigerator for 3 hours.
Prepare the jam. To cook it, place the pan on medium heat, bring to a boil and cook for another 20-30 minutes, stirring.
Preserve the jam for the winter. Pour the hot jam into jars and close with lids.