Instant Pot Orange Marmalade

Directions

1. Start by giving your oranges a good rinse under cold running water and leave to drain. One by one, halve the oranges and squeeze the juice into a measuring cup. You can use an electric squeezer, a standard hand squeezer or a reamer, but whichever you choose, ensure the juice drains through a medium-mesh sieve, as you only want juice in the measuring cup. Keep the orange remnants in the sieve: seeds, pith, and any other bits. These materials have pectin, which helps the marmalade set. Put the orange skin halves to one side.
2. Once all the oranges are squeezed, take a small spoon and scoop any remaining bits of fruit from inside the orange skins; add this to the sieve with the orange remnants. A note that you do not need to scrape the orange halves clean; any additional pith that clings to the skin will dissolve later on in the process.
3. Next, decide if you want a thick or thin-cut marmalade; this will determine how thickly you shred the orange halves. Slicing them approximately ½-inch wide will produce a substantial thick shred; ¼-inch wide, thin. Do not be alarmed, and do not be tempted to cut them any thinner; they will look chunky but reduce by at least half when cooked. I find it easier to cut the halves in two and put one on top of the other, then slice. There's no avoiding that this is a bit of a long job, but well-worth the effort you put in.
4. In a square of muslin or cheesecloth, place all of the orange remnants and pith and tie tightly. Set aside.
5. Pour the measured juice into the Instant Pot and add enough cold water for the liquid to come up to the 4-cup measurement on the side. Add in the orange skins, lemon juice, and muslin of orange pith. Secure the lid and pressure cook on high for 15 minutes; quick release the steam and remove the lid once cooked. Be careful at this stage, as the marmalade is very hot. Leave the lid off for 10 minutes to let it cool somewhat; carefully lift the muslin ball from the liquid and put it into a bowl to cool down enough to handle.
6. Once cooled, squeeze the muslin as hard as you can—this is fun but messy to do as the gooey liquid squeezes out, but all of this pectin is what will set your marmalade to perfection. Add every drop back to the marmalade and stir well. If you are in a hurry, you can also squeeze the muslin bag between two plates.
7. Grab a container of cold water and a large metal spoon. Turn the Instant Pot onto low sear, add the sugar, and stir until dissolved. Reset the heat on custom to 4 and bring to a rapid boil; as the mixture boils, the liquid will rise, and stirring this with the large metal spoon will calm the liquid. Then pop the spoon into the jug of water to keep it cool, repeating this stirring process as needed.
8. The marmalade is ready when either the temperature reaches 220°F (105°C) for a light colored marmalade or 230°F (110°C) for a deeper, vintage color. If you do not have a thermometer, no worries—you can ascertain doneness the following way: Place a saucer into the freezer; after 15 minutes of boiling, put a teaspoon of the hot marmalade onto the plate and leave to cool. Once cooled, push from the edge, and the marmalade should wrinkle up. If it does, it's ready. If not, boil a little longer and repeat.
9. Turn off the Instant Pot and leave the marmalade to cool for at least 15 minutes. While the marmalade is cooling, gather together 4 to 6 of your 16 oz. glass jars; wash them well in hot, soapy water, rinse them, and put it into a warm (250°F) oven for 10 minutes to dry them fully. Using a jam funnel, fill your jars up to the neck of the bottle, screw on a lid tightly, and leave to cool down completely. Your marmalade will keep well in a cupboard or the fridge for up to a year, though I doubt it will stay there that long.