Pink Grapefruit & Elderflower Marmalade

 

2 pounds, 4 ounces pink grapefruits

1 pound, 2 ounces lemons

6½ cups granulated sugar

6 T. elderflower syrup

 

Cut the grapefruits and lemons and squeeze in half out the juice and seeds. Tie the seeds, and any extra membrane that has come away during squeezing, in a double thickness of cheesecloth. Either by hand or using the shredding attachment of a food processor, thinly slice the grapefruit and lemon peel, with its pith, into shreds. Put the grapefruit and lemon juice and peel, cheesecloth bag and 7½ cups water in a preserving pan and slowly bring to a boil. Reduce the heat and simmer gently 1½ to 2 hours until the peel is soft and the liquid reduced by about half. Remove the cheesecloth bag from the pan and let cool 5 minutes before squeezing it well and allowing the juices to run back into the pan. Discard the bag. Add the sugar to the pan and stir until the sugar is completely dissolved. Bring to a boil and boil rapidly about 15 minutes, or until setting point is reached. Test for a set either with a candy thermometer (it should read 221°F) or put a tsp. of the marmalade onto a cold saucer and let cool a few minutes. If it wrinkles when you push it with your finger, then it is ready to use. Meanwhile, sterilize enough jars so that they are ready to use. Remove the pan from the heat and skim with a slotted spoon to remove any scum. Stir in the elderflower cordial. Let cool 15 minutes (this will help to prevent the peel from rising in the jars). Ladle the marmalade into the warmed, sterilized jars and cover immediately with sterilized lids. Label and store in a cool, dry, dark place. Refrigerate after opening.