Boil jars on a rack in a large pot filled with water for 10 minutes. Place flat lids in a saucepan with water. Bring to a boil; remove from heat. Let jars and lids stand in hot water until ready to fill. Drain well before filling.

Remove and discard colored and white parts of peel from grapefruit. Finely chop the fruit, reserving any juice; set aside.

Removed colored part of peel from half of the orange using a vegetable peeler. Cut into thin slivers; place in a 4-quart saucepan. Removed colored part of peel from half of the lime. Cut into thin slivers, add to the saucepan. Remove and discard remaining colored and white parts of peel from the lime. Finely chop the fruit to make 4 cups, reserving any juice and set aside.

Add 3 1/2 cups water and baking soda to saucepan. Bring to a boil. Reduce heat; cover and simmer 20 minutes. Add prepared fruit; cover and simmer 10 minutes. Measure 4 cups into a 6-quart or 8-quart saucepan.

Measure sugar into a separate bowl. (Scrape extra sugar from cup with spatula to level for exact measure.) Stir pectin into fruit in saucepan. Add butter. Place over high heat; bring to full rolling boil, stirring constantly. Remove from heat; skim off foam with a metal spoon.

Ladle quickly into prepared jars, filling to 1/8-inch of the tops. Wipe jar rims and threads. Cover with two-piece lids and screw on bands tightly. Process the jars by placing them in a large pot with enough water to cover the tops of the jars by at least 1 inch. Boil for five minutes. After jars cool, check seals.

This recipe yields about 7 one-cup jars.

Source: "Lynn Thomas on the Food Forum BB at http://food.bb.prodigy.net/"S(Formatted for MC5): "08-21-2000 by Joe Comiskey - jcomiskey@krypto.net"Yield: "7 one-cup jars"

NOTES : Recipe as published in The Capitol-Journal, 12-10-1997