Sweet Grapefruit Marmalade

2 large pink or white grapefruit (about 1-1/4 lbs. each)
1 samall lemon
Water
About 5 cups sugar

1. Using a vegetable peeler, remove colored part of peel from
grapefruit and lemon. Trim off any white pith left on peels. Stack
peels and cut crosswise in thin slivers.
2. Bring slivers of peel and 4 cups water to a boil in a saucepan.
Drain. Repeat twice (to remove bitterness).
3. Trim white pith from fruit. Finely chop fruit, discarding seeds
and saving all juice.
4. Mix peels, fruit juice and 2 cups water in a heavy-bottomed 4-quart
pot. Bring to a boil, reduce heat and simmer, uncovered, 12 minutes.
Cool, cover and refrigerate overnight.
5. Heat oven to 250. Wash four 1-cup jars with tight-fitting lids.
Stand upside down in a baking pan and keep in oven until ready to
fill.
6. Measure fruit mixture. For each cup, add 1 cup sugar. Return to
pot. Slowly bring to a boil over medium-low heat, stirring
occasionally, until sugar dissolves.
7. Boil gently, uncovered, 35 to 45 minutes or until a candy
thermometer registers 220F to 225F (or syrup runs off a cold metal
spoon in a jellylike sheet). Remove from heat. Stir about 1 minute,
then skim off and discard any froth.
8. Ladle into hot jars to within 1/8 inch of tops. Wipe rims and
cover tightly. Cool and refrigerate.