Orange & Grapefruit Marmalade

1kg oranges
1kg grapefruit
2kg sugar
1/2 cup whiskey
Fresh ginger (about thumb size finely grated)

1. Finely slice unpeeled fruit, place in a preserving pan and cover with 2 litres of water. Cover and leave to soak overnight
2. The next day, place the pot over a high heat, bring to the boil and boil for 40 minutes
3. Lower the heat and add the sugar and ginger stirring until dissolved
4. Return to the boil for about an hour, stirring regularly to prevent the mixture from sticking to the bottom of the pot
5. After about an hour do a ‘set test’ on a cold saucer by dropping a tablespoon of marmalade onto it. The marmalade is ready when it forms a skin that wrinkles when you hold the plate on an angle.
6. At this point add the whiskey and boil for couple of minutes more to burn off the alcohol
7. Pour straight into sterilised jars and seal