Prepare the glass jars by washing thoroughly in hot, soapy water. Rinse, drain and then place in warm oven at 50°C until jam is ready for jarring.
Remove the calyx from grapefruits and lemons, wash thoroughly in warm water to remove the wax from the skin.
Using a heavy based saucepan add the water and grapefruits, bring to the boil on a medium heat with lid on. Turn the heat down to low before adding the lemons, cook for 45 minutes with the lid on, stirring occasionally, ensuring the fruit cooks evenly. After 45 minutes fruit should be tender.
Place a colander over a large heatproof
container and pour fruit and cooking liquor into the colander. Retain the cooking liquor in the heatproof container and set the fruit aside to cool for 30 minutes.
Add 4.5 litres of cooking liquor and sugar to the heavy based saucepan, cooking on a medium heat, stirring occasionally, until sugar is thoroughly dissolved. Remove from heat and set aside until required.
Using a sharp knife, half the grapefruits and lemons then remove the centre flesh and pips from the skin. Place fruit and peel into separate clean containers. Slice the peel finely into ½ cm wide strips.
Use a wooden spoon to press the juice and
flesh through a sieve, discarding the membrane and pips.
Add the finely sliced peel and juicy pulp into the sugared liquor, cook on a high heat for approximately 35 – 40 minutes stirring occasionally, until the marmalade reaches 112°C.
When marmalade reaches the correct temperature it will appear thick and glossy. Remove from the heat and empty marmalade into a heatproof container and leave to stand for 10 minutes.
Ladle your marmalade into a measuring jug, before filling and lidding each jar.
2.4kg Pink grapefruit
700g White grapefruit
2.7kg Golden granulated sugar
10Ltr Heavy based saucepan
Large heatproof container
22 227g/8oz Glass jar
22 Suitable twist off lids