Grapefruit and brandy marmalade

Method

1. Set a sieve over a large heavy-based saucepan and squeeze the grapefruits and lemons into the pan. Put the pulp and pips from the sieve into a piece of muslin. Scrape the membrane from the fruit shells and put it into the muslin (it helps if you turn the skin inside-out), 
then tie the muslin into a parcel.
2. Finely slice the peel and add to the pan with the muslin parcel, juniper berries and 1.5 litres water. Cover the pan with cling film and leave to infuse overnight.
3. The next day, bring the mixture to the boil over a medium-high heat, then turn down the heat and simmer gently for 
2 hours. Remove the muslin parcel and carefully squeeze out the liquid into the pan. Add the sugar and stir until combined. Turn up the heat and bring to a rolling boil. Cook for 20-30 minutes, then take off the heat and test to see 
if the marmalade has reached setting point. If it’s not ready, put another saucer/small plate in the freezer and reboil the mixture; test every 
2 minutes until setting point is reached. Stir in the brandy.
4. Pour the marmalade into still-warm sterilised jars, poke in a few rosemary sprigs and seal.