Wash clean glass jars and lids with hot water or run through the dishwasher. Dry thoroughly. (You'll end up with about 5 cups of jam, so the number of jars you'll need will depend on what size they are.)

Remove colored zest (just the colored part, not the white pith) from the oranges and the lemon, using a small zester (I love this one). If you can’t get one of the small zesters, use a vegetable peeler to remove just the colored zest. Then cut the peel into thin slivers, or finely chop. Transfer the zest to a small bowl and set aside.

Cut the remaining peel off of the oranges. Slice oranges then coarsely chop, reserving any juice. Transfer oranges and juice to a bowl.

Add one cup of coarsely chopped cranberries to the oranges and stir to combine. Transfer exactly 2⅓ cups of the fruit mixture to a large pot. If you don’t have quite enough, add a bit of water or orange juice to make exactly 2⅓ cups. If you have extra, discard (or use for something else) any remaining fruit mixture.

Add the sugar to the pot and stir until well mixed. Turn the heat to medium-high and stir frequently until the mixture comes to a full rolling boil (a boil that you can’t stir down). Set a timer for 30 seconds and boil, stirring continuously. After 30 seconds, remove from heat.

Add ¾ cup water to a small saucepan. Sprinkle in pectin and stir until dissolved. Bring the mixture to a rolling boil and boil for 1 minute, stirring continually.

Transfer marmalade to prepared containers immediately and fill to within ½ inch of tops. Wipe off top edges of containers and immediately cover with lids. Let stand at room temperature a few hours (if you can wait!). Store in refrigerator up to 3 weeks or freeze extra containers up to 1 year. Thaw in the refrigerator before using it.