Fill a medium saucepan with about 2 inches of water and bring to a gentle simmer over medium heat. Remove any seeds as you see them, placing them into a muslin tea bag or a square piece of cheesecloth. If it fails to wrinkle or is obviously still runny, boil the marmalade for several minutes longer, then repeat the gel test. Recheck the headspace and add or remove marmalade as necessary. Carefully remove the jars from the canner, using either the canning rack handles or a jar lifter.