Recipe Detail Page

1 Cut a 10-inch (25-cm) square of double thickness fine cheesecloth; rinse, wring out and spread to line a large sieve. Set sieve over an 8-cup (2-L) measuring cup or bowl.

2 Scrub grapefruits and lemon in warm sudsy water; rinse well. Cut out blossom ends and trim off any blemishes. Cut grapefruit and lemon in half; squeeze out juice, dislodging any seeds. Strain juice through the cheesecloth-lined sieve, reserving any seeds and pulp on the cheesecloth. Pull out membranes from grapefruit and add to the lined sieve. Cut the lemon into 8 chunks and add to the lined sieve. Bring up cheesecloth sides loosely but completely enclosing the contents and tie top with cotton string. Place the cheesecloth pouch and grapefruit and lemon juice in a large saucepan.

3 Cut the grapefruit halves into eighths, then crosswise into paper-thin strips; add to juice in the saucepan, along with the water. Bring to simmer over medium heat. Cover, reduce heat to low and simmer gently, periodically pressing seed pouch to release pectin. Continue simmering until peel is translucent and a strip of peel mushes when pressed between fingers, about 2 to 2½ hours. Remove pouch; firmly squeeze its juice back into pan. The peel mixture should measure 7 cups (1.75 L); if not, add water to make up difference or boil until reduced to this amount.

4 Combine the sugar and fruit mixture in a large wide heavy-bottom saucepan or Dutch oven. Stir well; bring to full rolling boil, stirring. Boil vigorously, stirring constantly, until the marmalade clears, has thickened and reached its setting point,*bout 10 to 14 minutes. Remove from heat; stir in the rum.

5 Pour into prepared preserving jars, leaving ¼-inch (5-mm) headspace. Seal with prepared discs and bands. Boil in boiling water canner 10 minutes. Uncover; let boiling subside. Remove jars; cool on rack.