Ingredients
6 cups chopped fresh or frozen rhubarb6 cups sugar2 medium oranges
Preparation
Combine rhubarb and sugar in a Dutch oven. Grind oranges, including the peels, in a food processor; add to rhubarb mixture. Bring to a boil. Reduce heat and simmer, uncovered, stirring often until marmalade sheets from a spoon, about 1 hour.
Remove from heat; skim off foam. Ladle hot mixture into eight hot half-pint jars, leaving 1/4-in. headspace. Remove air bubbles and adjust headspace, if necessary, by adding hot mixture. Wipe rims. Center lids on jars; screw on bands until fingertip tight.
Place jars into canner with simmering water, ensuring that they are completely covered with water. Bring to a boil; process for 10 minutes. Remove jars and cool.
