Orange and grapefruit marmalade

Wash the oranges and grapefruit in cold water, then drain and dry with kitchen paper. Cut in half and squeeze the juice into a large pan. Remove the pips and put them on a piece of muslin or a clean J cloth or large handkerchief (the pips contain pectin, which makes the marmalade set.) tie into a bag with string and put the bag in the pan.

Cut the orange and grapefruit rind into shreds and add to the pan with 3 litres water. Bring to the boil, then simmer gently, uncovered, for about 2 ½ hours or until the rind is soft and looks transparent.

Remove the bag of pips and put it in a colander over a bowl. Press firmly with the back of a spoon to squeeze out all the juices. Add the juices to the pan and discard the bag.

While the fruit is simmering, wash, rinse and dry four jam jars and put in the oven at the lowest setting to warm and sterilise. Put a saucer or small plate in the fridge.

Add the sugar to the fruit mixture in the pan and reduce the heat. Stir gently until the sugar has dissolved, then increase the heat and boil rapidly for 5-20 minutes or until setting point is reached, testing the marmalade every 5 minutes. To test for setting, put 1 tsp of the marmalade on a chilled saucer and leave for 1 minute. Push the edge with your finger – if the top wrinkles, the marmalade is ready.

Leave to cool for 10 minutes, then spoon into the warm jars. Cover with jam pot covers and label.