Ingredients

454g  Seville oranges

200g Clementines

25g lemon

1.4kg granulated cane sugar

1.75 litres  water

1. Weigh the preserving pan un  lidded and empty. Record the weight. Prepare the marmalade by juicing all the fruit and removing all the inner membranes but leaving the pith attached to the rind. Finely chop the inner membranes of the Sevilles, and lemon.  Add all the chopped membranes to a square of muslin, 36 x 36cm, along with any pips.Tie the muslin securely with string.

2. Shred of the Sevilles, lemon and the clementines. Add the peel, the muslin bag and water to the pan. Leave the pan to soak overnight.

3. Next day, bring the lidded pan to a boil, turn down the heat and simmer gently for two hours. Remove the lid and set aside. The peel should be tender and the contents of the pan reduced by a third.

4 Remove the muslin bag and squeeze the liquid from the bag back into the pan through a sieve, using a large spoon. 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 1.25kg. If the weight is more, return the pan to the heat and simmer gently. Check the weight every 5 minutes, until the desired weight is reached.

5 Warm the sugar in a low oven at 120C . Add the sugar to the pan and dissolve it slowly. Put the jars in the oven 120C for 20 minutes.

6. Bring the pan to a rolling boil and test for a set after 10 minutes, using the flake test. Once setting point is reached, turn off the heat and leave the marmalade to cool for at 10 minutes. Remove any scum from the surface of the marmalade, using a metal spoon. Gently stir the marmalade.

7. Pour the marmalade into clean, warm, sterilised jars and cover with new twist top lids. Leave the jars upright and undisturbed to set.