Mirabelle Plums in Glass, Grandma’s Style

The first thing you need is empty jars with twist-off closures. These should be cleaned thoroughly and rinsed out with boiling water. The lids also have to be very clean to be successful. Now bring the sugar to the boil with the water until it is completely dissolved. Fill the mirabelle plums (only the flawless ones with no pressure marks) into the glasses and fill them up to just below the rim with the sugar water solution. Close the jars tightly. Now place them in a wake-up pot. Pour in enough water until the glasses are 2/3 in the water. Place a thermometer in the pot to check the exact temperature. The glasses must now be heated for 30 minutes at 80-85 degrees. After this time, take the jars out of the pot and let them cool down slowly until a vacuum has been created (lids of the jars bulge slightly inwards)