Granny's Mulled Wine

Every year on Christmas Day Granny arrives for lunch armed with an orange flask full of mulled wine. This is her recipe:

1 bottle of red wine
1/2 pint water
1/3 rind tangerine
6 tablespoons sugar
6 cloves
1 cup of brandy (optional).

Warm the ingredients (except the brandy) gently until it steams but don't let it boil. Remove the tangerine peel and cloves, and then add the brandy before serving.