Cut the strawberries into small pieces and mix them with the remaining ingredients in a large pot. Refrigerate for at least 2 hours.
Then simmer the strawberry mixture for about 5 minutes and puree with a blender. Heat the prepared glasses in the oven at 150 °C.
Pour the simmering jam into the hot jars and close them immediately. Depending on your taste, you can also add some rum to the strawberry jam.
Add the rum to the pureed strawberries before filling the jars.