- 4 Ruby grapefruit
- 4 limes
- 1½ kg jam-setting sugar
- ½ cup limoncello
Preparation time: 20 minutes
Cooking time: 2 hours
1 Use a peeler to remove the grapefruit zest, then cut into fine slices. Halve the grapefruit and limes, then squeeze the juice into a large saucepan. Discard the lime centres. Use a sharp knife to remove the white grapefruit pith and discard. Wrap the remaining grapefruit centres in muslin and add to the saucepan.
2 Pour 1½L water into the saucepan and set over a moderate heat. Simmer rapidly for 1 hour. Remove the muslin bag and allow to cool slightly, then squeeze its liquid into the saucepan. Discard the muslin.
3 Add the sugar and limoncello to the saucepan and bring to a rapid boil for 10 minutes. Test for set on a chilled plate. If set, ladle into sterilised jars and seal while hot. If not yet thick enough, boil for 5 more minutes and re-test.