How to make
The blueberries are cleaned from the leaves and they are washed.
Sprinkle them with sugar and leave them overnight in a cool place.
The next day, water is added to them and they are placed on the stove. The jam is boiled over moderate heat, by occasionally removing the resulting foam.
The jam is boiled to a thickness, which is determined, by dropping a drop of it on a plate seeing whether it stays in place or if it's still to liquid. Do not boil grandma's jam for too long.
After it cools, the blueberry jam thickens even more.
Finally, citric acid is added and the jam is removed from the heat.
The warm jam is distributed into warm and dry jars.
Turn them upside down and leave grandma's blueberry jam like that, until it has completely cooled.
Note: We're leaving another classic blueberry jam recipe at your disposal.