In a pitcher, mix the juice of 1 lemon, 50ml of maple syrup and 500 ml of water.
Add a pinch of cayenne pepper or 1tsp fresh ginger to taste.
Adjust the amount of maple syrup accordingly to the acidity of the lemon.
Refrigerate for a few hours, filter if you want to remove the ginger.
Before serving, moisten the rim of the glass with a lemon wedge, then dip it in maple sugar. Serve chilled with ice cubes and decorate the glasses with a slice of lemon.