Orange, grapefruit and lemon marmalade

Squeeze the orange and lemon juice into a large pot.

Remove the pith and membranes from all the peels.

Chop the grapefruit flesh into rough chunks and add it to the pot.

Place all pith, membranes and pips in a muslin cloth, tie this to form a pouch and suspend it in the juices by attaching it to the handle of the pot with string.

Roughly shred all the peels and add them to the pot along with the water. Bring to the boil, then reduce the heat and simmer gently until the peel is soft and the mixture has reduced by half, about 2 hours. Remove and discard the muslin bag.

Add the warmed sugar and stir over low heat until the sugar has completely dissolved. Increase the heat to high and boil rapidly until a sugar thermometer reads 105°C. Remove from the heat and skim off any scum from the surface with a slotted spoon. Allow to stand for 15 minutes.

Pour into sterilised jars and leave overnight to set. Store in a cool, dark, dry place.