Wash and remove the skin from the ginger. Chop the ginger and blend in a little water.
Pour into a large pot with the rest of water and leave to soak and ferment for about 24 hours or longer if you want it stronger tasting.
When fermented, strain the mixture. Add lime peel to the ginger beer and sweeten to taste. Remove the lime peel, bottle and refrigerate. Serve chilled.