Rhubarb-Plum Jam

1 . Stage

Combine rhubarb, plums, sugar, orange juice, water, and orange zest in a saucepan over medium heat; bring to a boil. Reduce heat to medium-low and cook, stirring occasionally, until thick, about 45 minutes.

2 . Stage

Meanwhile, inspect 6 pint-sized jars for cracks and rings for rust, discarding any defective ones. Immerse in simmering water until jam is ready. Wash new, unused lids and rings in warm soapy water.

3 . Stage

Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil.

4 . Stage

Pack jam into hot, sterilized jars, filling to within 1/4 inch of the top. Run a clean knife or thin spatula around the insides of the jars to remove any air bubbles. Wipe rims with a moist paper towel to remove any residue. Top with lids and screw rings on tightly.

5 . Stage

Lower jars 2 inches apart into the boiling water using a holder. Pour in more boiling water to cover jars by at least 1 inch. Bring to a rolling boil, cover, and process for 5 minutes.

6 . Stage

Remove the jars from the stockpot and let rest, several inches apart, for 12 to 24 hours. Press the center of each lid with a finger to ensure the lid does not move up or down. Remove the rings for storage and store in a cool, dark area.