This is a recipe that I made a few years ago and haven’t uploaded to this site yet. It’s inspired by this one and makes a few pints, though I halved the amount and made enough to fill one pint-sized Mason jar and 3/4 of a quart-sized jar (because I didn’t check to make sure we had enough smaller jars before I started). 

My batch differed in the final stage, when it said to boil on medium for 30 minutes until it hit 220F. Mine hit 220F at about 12 minutes into that stage, and the cold saucer test was still kind of runny, but I didn’t want to keep it at that temperature for too long when the recipe said to turn off the heat as soon as it hit. I think I boiled at that temperature for another 5 minutes or so while I dithered.

The recipe said that the pectin would take another day or two to really set up, which indicates that it should still be a bit runny after boiling, in my take on it. I poured it into jars a couple minutes after turning off the heat and the lids sealed themselves.

This is a two-day recipe, so plan ahead to make this over a weekend or when you have plenty of time.

Full-Sized Recipe:
4 large seedless oranges scrubbed clean (~3 pounds)
2 lemons (~ ½ pound)
8 cups water
8 cups granulated sugar
whole cloves or cinnamon stick (optional)

Half-Sized Recipe:
2 large seedless oranges scrubbed clean (~1 1/2 pounds)
1 lemon 
4 cups water
4 cups granulated sugar
whole cloves or cinnamon stick (optional)

Day 1:
First, cut washed oranges and lemons into quarters, then into very thin quarter-moon slices. A mandoline makes short work of this, though it will totally cut off your fingertips and you’re justified in choosing a knife instead.

Discard any seeds and check the lemons for cut seeds as they are sneaky. Place the sliced fruit along with their juices into a stainless steel pot.

Add water and bring to a boil, stirring often. Remove from the heat and add the sugar until it dissolves. Add any spices you feel like sticking in. Cover and let stand overnight at room temperature.

Day 2:
Bring the mixture back to a boil. Reduce the heat to low and simmer uncovered for 2 hours. Turn heat up to medium and boil gently, stirring often, for another 30 minutes.

Skim off any foam that forms on the top. Cook the marmalade until it reaches 220 degrees (you must hit this temperature for the natural pectin to gel with the sugar).

If you want to be doubly sure the marmalade is ready, place a small amount on a plate and refrigerate it until it’s cool but not cold. If it’s firm–-neither runny nor hard–- it’s ready. It will be a golden orange color. If the marmalade is runny, continue cooking it; if it’s hard, just add a bit more water.

Pour the marmalade into sterilized mason jars, Follow these canning tips for advice on going about this.

Wipe the rims thoroughly with a clean, damp paper towel, and seal with the lids. Chill in the refrigerator. It may take 24-48 hours for the natural pectin to set up properly.