Rhubarb Grapefruit Marmalade

Place 2 plates in freezer to test for setting point.

Scrub grapefruit; cut out stem and blossom ends and any blemishes. Cut in half crosswise. With citrus juicer, squeeze out juice of grapefruits and lemon, dislodging seeds. Strain through sieve into bowl; set juice aside. Remove membranes and set aside.

Place seeds and any membranes on 8-inch (20 cm) square double-thickness fine cheesecloth. Bring up sides; tie top with string, enclosing seeds loosely. Place in large heavy saucepan. Pour in juice.

On cutting board, stack grapefruit skins. Cut into 3 parallel strips; cut away excess white pith from strips. Cut crosswise into slightly less than 1/4-inch (5 mm) thick strips. Add to pan.

Add 5 cups (1.25 L) water to pan; bring to simmer over medium heat. Reduce heat, cover and simmer gently, stirring often, for about 2-1/2 hours or until peel turns to mush when pressed between fingers.

Remove seed bag and let cool; squeeze juice from bag into pan. Mixture should measure 5 cups (1.25 L). If more, uncover and simmer longer; if less, add water.

In clean Dutch oven, stir together grapefruit mixture, sugar and rhubarb; bring to boil over high heat, stirring constantly. Boil vigorously, stirring constantly, until setting point is reached, about 20 minutes. To test, remove from heat. Drop 1 tsp (5 mL) mixture onto 1 chilled plate; freeze for 1 minute. Remove from freezer. Surface should wrinkle when edge is pushed with finger. If too liquid, return to heat and repeat test every few minutes with chilled plate. Skim off foam.

Pour into prepared 1-cup (250 mL) canning jars, leaving 1/4-inch (5 mm) headspace. Seal with prepared discs and bands. Boil in boiling water canner for 10 minutes.

Additional information : Tip: Citrus fruit can vary greatly in the amount of pectin. If your grapefruit has a high amount, the marmalade may set more quickly and you may get an extra jar of jam.

Source : Canadian Living Magazine: June 2008