Prepare the canner: Fill a water bath canner and bring it to a simmer, about 180°F. Keep hot while preparing the jars.
Fill the jars: Add 1½ to 1¾ cups raw cranberries to each quart jar. Add ¼ to ½ cup sugar to each jar, if using.
Add boiling water: Bring a kettle of water to a full boil. Carefully pour boiling water over the cranberries and sugar, leaving ½ inch headspace.
Remove air bubbles and seal: Gently remove air bubbles, wipe rims clean, apply lids, and screw rings on fingertip tight.
Process the jars: Place jars in the canner and bring the water to a full rolling boil. Once boiling, start timing.
Cool and store: Remove jars and let cool undisturbed on a towel for 24 hours. Check seals. Refrigerate any unsealed jars. Store sealed jars in the pantry.
Infuse before using: Allow jars to sit for 4–6 weeks so the berries can fully infuse before drinking.