Remove the stems from the herbs, rinse them briefly and dry them with a kitchen towel. Crush the herb mixture in a mortar and pour the alcohol over it in a mason jar. Put in a light place for twelve days and let it steep.
Then add the lemon peel and let it steep for another 2 days.
Boil the sugar with the water until the sugar has dissolved. Let cool and add to the herb mixture. Let stand for a few more hours, preferably overnight, and filter off.
Bottle and let rest for a few more weeks in a cool and dark place. Makes about 1 liter of liqueur.