Cranberries for winter with blueberries

From TV screens they tell us that blueberries are the best prevention of vision problems. Lingonberries themselves are very tasty. And if you combine both berries, you can treat yourself to harvesting cranberries for the winter with blueberries. Only freshly picked cranberries are suitable for canning, otherwise it will be bitter not only in food, but also during preservation. Blueberries should be fully ripe.
At one time I visited a sick grandmother in the hospital and her roommate taught me how to cook delicious jam from these wonderful berries according to a recipe.
We will wash the berries in several waters, clean them from impurities and stalks. Carefully inspect the ingredients for damaged or rotten berries.
At the beginning we will prepare the berries. Pour water into a saucepan, pour them into the water and steam until softened. Using a blender or meat grinder, or maybe a sieve, we will turn blueberries and lingonberries into mashed potatoes. We will combine both purees, and put them in a bowl for cooking jam. Do not forget to add sugar.
Bring the jam to a boil over low heat and cook at a time until ready. The process lasts until the volume decreases to 1/3 of what it was at the beginning. The finished product slides off the spoon in chunks. In jars, pack hot and wait a few days before capping – until a crust appears. Plastic lids are enough for jam.