Wash the pineapple thoroughly and peel it very sparingly, removing only the outermost skin
Cut into pieces and place in a pot with about ½ liter of water
Roughly chop the ginger or crush it in a mortar so that the juice is easily extracted from the fibers later
Add the crushed ginger to the pot with the pineapple pieces
Bring everything to a boil and cook for about 10 minutes.
Then turn down the heat and simmer covered for another 10 minutes over medium heat
Remove from the oven and let cool for approximately another half hour
Blend in a blender, then filter the juice using a fine sieve until all the remaining pulp has been extracted
Pour the resulting juice into a carafe with the remaining water
Add lemon slices, mint leaves and sugar to taste, stir well and chill in the refrigerator for about an hour or serve immediately with ice cubes.