Sort the cherry plum, remove the stems, and wash. Prepare a saucepan and sterilized jars with lids for the finished jam.
Pour the cherry plum into a saucepan, add water and cook over low heat for 15 minutes. The cherry plum should be steamed so that it can be easily rubbed through a sieve.
Place a colander with a mesh over a deep saucepan and puree the cherry plum in small portions using a masher or spoon. The puree will drain into the pan under a colander, and the pits and skins should be discarded.
Pour sugar into the resulting puree, stir and cook for 30-40 minutes over low heat, stirring constantly so as not to burn. Pour the finished jelly into jars, screw on the lids and let cool. Store in a cool place.
Cherry plum jelly can be served with pancakes, semolina porridge or used as a filling for pies.