Made with a few fresh ingredients, including citrus and fruit, this rhubarb jam is the essence of spring! To make it last longer, a quick water bath on the stove is super simple!
In a large heavy-bottomed stockpot, combine the rhubarb, sugar, lemon zest, orange zest, lemon juice, and orange juice. Bring to a rolling boil over medium heat. Keep at a low boil, stirring occasionally for 15 minutes.
Remove from the heat and strain the juice. Reserve the rhubarb. Return the strained juice to the stockpot and cook until the temperature reaches 221°F.
Once at the correct temperature, add the reserved rhubarb back to the juice and return to a boil. Cook for 2 minutes just to heat the rhubarb.
For canning: Immediately pour the hot jam into warm sterilized jars, leaving ¼-inch headspace. Wipe the rims of the jars with a clean cloth and add the lids and rings according to the manufacturer's instructions.
Boil in a water bath: 10 minutes for 8 oz jam jars and 15 minutes for pint jars. Remove from the water bath and cool on a rack for 24 hours before removing rings. Store for up to one year.