Cut the hard stalk of the pineapple that you have cut out and wash the mint well. Pour into a carafe or jug, pour cold water over it and let it steep in the refrigerator overnight.
Tip: Instead of the stalk, you can of course use a handful of pineapple pieces or both. Let it steep - it takes time for the pineapple to give off its flavor. Dose the mint according to taste and aroma.