Texas Red Grapefruit Marmalade

Place a saucer and 2 small spoons in the freezer for testing the marmalade thickness later.

Cut 1 inch off both ends of each grapefruit and reserve. Cut the fruit into very thin round slices. Coarsely chop half the slices; cut the remaining slices into quarters. Reserve any seeds. Reserve any juice that accumulates on the cutting board.

Wrap the reserved ends and seeds in a double layer of cheesecloth and tie closed. Place in a large nonreactive pot (see Tip). Add the fruit, the reserved juice, sugar and water. Cook over medium heat, stirring frequently, until the sugar is completely dissolved, 2 to 3 minutes.

Increase heat to high and boil rapidly, stirring frequently and scraping the bottom with a heatproof spatula to prevent sticking, until the mixture thickens and most of the fruit separates from the peels, about 15 minutes. Remove from heat.

To test, place a little of the liquid (without any solids) on a frozen spoon. Rest it on the saucer and return to the freezer for 3 to 4 minutes. Then drop the sample onto the saucer: if it's thick enough to mound without quickly running or spreading, the marmalade is ready. If it's runny, return the pot to a boil and cook for another 3 to 5 minutes before testing again.

When the marmalade passes the thickness test, discard the cheesecloth bag. Let cool completely before serving or refrigerating.