Start making the jam. Mix the chopped apples with sugar and leave for 30-40 minutes to release the juice. Then transfer the apple mixture to a deep baking dish and place in a preheated oven for about 20 minutes. Watch the process: as soon as the apple mixture boils, the jam is ready.
Prepare the jam for storage. Let the hot jam cool and then mince the mixture or process it with a blender until you get the desired consistency. Then put the jam in a thick-bottomed saucepan or cauldron and bring to a boil. After boiling, cook for 1 minute.
Pour the jam into jars. Pour the finished jam into clean, dry jars. The less air there is in the container, the longer the jam will last. Seal the lid tightly and store in a cool, dark place.