Ingredients

675g Seville oranges
1 lemon
1.4kg granulated, cane sugar
1.75 litres water
25ml London Gin
25ml Vermouth
25ml Campari

1. Weigh the preserving pan empty and without the lid. Record the weight.Juice the oranges and pour the juice with the water into the pan. Remove the inner membranes and pips from the oranges. Do not remove the pith from the oranges.

2. Juice the lemon and add the juice to the pan. Put the remains of the lemon, and the  orange membranes into a food processor or mini-chopper and chop finely. Put the chopped remains and any pips into a 36 cm x 36cm piece of thin cotton muslin. Tie this up with string and add it to the pan.

3. Shred the oranges and add the peel to the pan- thinner peel releases more pectin during cooking than thicker peel. If possible, leave the pan overnight to allow the fruit to soak. Next day, bring the lidded pan to boil, turn down the heat and simmer very gently for two hours. Remove the muslin bag and squeeze the liquid from the bag back into the pan through a sieve, using a large spoon. Discard the muslin bag.

4. Weigh the pan on a flat set of scales, protected with a trivet or heat resistant mat. Look for a weight of the empty pan (see point 1 ) plus 1.4kg. If the weight is more, return the un lidded pan to the heat and simmer gently, checking the weight every 5 minutes until the desired weight is reached.

5. Warm the sugar in a low oven for 20 minutes. Add the sugar to the pan and dissolve it carefully. Put he jars in the oven to warm through.

6. Bring the pan to a rolling boil and test for a set after 8 minutes, using the flake test. Turn off the heat and leave the marmalade to cool for 10 minutes. Remove any scum from the surface of the marmalade. 

7. Add the negroni mixture to the pan and stir to combine. Pour  the marmalade into warm, clean, sterilised jars and cover with new twist top lids. Leave the jars upright and undisturbed to set.