500 grams sugar
1 kg blueberries Wash the blueberries. Place them in a large cooking vessel, preferably a heavy duty one such as a copper or a cast iron pot. Bring the berries to a boil, stirring often. Add the sugar. Stir the jam often with a wooden spoon to avoid scorching. Cooking time depends on how much water is in the berries. I test it placing a few drops of jam on a plate, I tilt the plate and if the drops of jam stop running after about 1 inch the jam is done. Ladle the jam into previously sterilized jars. Cover with a lid. Do not tighten the lids to much. Sterilize all the jars in a boiling water bath for about 10 minutes. With a jar tong remove the jars from the water to cool off. While cooling the jar lids should pop. You can hear the popping sound. When the jar lids are all popped and caved in give them a final sqeeze to sicure the seal.
