1. In a clean saucepan, bring the water, sugar, lemon zest and bruised ginger to a boil. Then simmer for one hour.
2. Skim off any scum and pour into large bowl. Allow to cool briefly.
3. When tepid, add the yeast, cover with a cloth and leave overnight.
4. Add lemon juice and raisins and pour into a large lidded container. (If using more than one container, distribute the hard ingredients evenly). Place the lid over the container loosely.
5. Stir every day for two weeks.
6. After two weeks, add the brandy. Over a couple of weeks, gradually screw down the lid. Strain and bottle just before serving.
For more information on home-made flavoured alcohol, read Julia Watson's article Make your own boozy Christmas gifts.