Remove the stalk and skin from the pineapple, cut into pieces and place in the pot. Add a splash of lemon, as well as the pinch of cinnamon and the preserving sugar. Now boil vigorously for three minutes and skim off the foam. Add the kirsch, turn off the stove and put the sterile glasses with the lids ready. Pour in, close with the twist-off lid and let cool upside down.