Heat jars in a water bath canner and heat water in a separate pot. The water in the pot is used to cover the cranberries and sugar in the jars.
Using a funnel, pour 1 1/2 cups of cranberries into each quart jar and top it with 1/3 cup of sugar. Add enough warm water from the pot to leave a 1-inch head space. Poke down the cranberries to remove any air bubbles.
Wipe each jar rim with a towel dipped in white vinegar to remove any residue that could disrupt the seal.
Place the lids on and screw the tops on hand-tight and place in the water bath canner.
Bring the water to a boil, if it isn’t boiling already, and let jars bathe for 25 minutes.
Remove jars from the canner and let them sit for 24 hours, undisturbed. Check the seals by pressing the middle tab and holding two edges of the lid to see if the lid comes off. Make sure your other hand is below the jar, ready to catch it, when you do this. If sealed properly, allow to sit for at least 6 weeks; then enjoy!