Rhubarb Orange Vanilla Jam

Ingredients

• 6 cups granulated sugar
• 2 large navel oranges
• 5 cups finely chopped rhubarb
• 1 vanilla bean
• One package regular powdered pectin
• 1/2 teaspoon unsalted butter

Directions

1. If you plan to can the jam, get the jars and lids ready first. Set 6 half-pint jars on a rack inside a large pot, pour in enough water to submerge them, and set the pot over high heat until the water boils. Keep it boiling for 10 minutes, then shut off the heat and leave the jars in the hot water. While that is happening, place the bands and lids in a small saucepan, cover them with water, and warm them over medium heat until the water simmers. Take the pan off the heat, and let the bands and lids wait in the hot water until you need them.
2. Measure the sugar into a large bowl and put it aside. Wash 1 of the oranges, then peel off the rind in quarters. Cut the rind into thin lengthwise strips, trimming away any extra pith as you go, then chop those strips crosswise into little pieces. Juice both oranges. You should end up with about 1 cup; if you are short, add water to make up the difference.
3. In a large, heavy-bottomed pot, combine the chopped orange rind, orange juice, and rhubarb. Cut the vanilla bean open lengthwise, scrape the seeds into the pot, and drop in the bean as well. Scatter the pectin evenly over the fruit, then cook over medium-high heat, stirring often, until the mixture reaches a full boil.
4. Pour in the sugar all at once, stirring until it dissolves. Add the butter, then keep cooking and stirring constantly until the jam reaches a full rolling boil. Let it boil hard for 1 minute. Take the pot off the stove, and skim off any foam sitting on top of the jam.
5. Spoon the hot jam into the hot sterilized jars, leaving 1/4-inch of headspace. Clean the jar rims, set the lids in place, and screw on the bands until they are only lightly tightened. Put the jars on a rack in the pot and add water so they are completely covered. Cover the pot, set it over high heat, and bring the water to a boil. Boil for 10 minutes. Turn off the heat, remove the cover, and let the jars sit in the water for five minutes. Lift out the jars and leave them untouched on the countertop for six hours or overnight.