Cut the ginger into small pieces and lightly crush it in a mortar. Wash the dandelion and nettle leaves, put them in a very large saucepan and pour 500 ml of water. Add ginger and grated lemon and orange peel. Heat to boiling point and simmer for about 30 minutes. Put the sugar in a second large saucepan and pour the boiling liquid through a sieve. Stir until the sugar is dissolved. Add 1 quart of cold water, cool the liquid until it is just lukewarm.
Add the yeast. Cover the pot with a kitchen towel and let it stand overnight in a warm place. The next day, skim the foam from the surface and bottle the beer. Seal the bottles and let the beer rest for 7 days until ready to drink.