Wash your oranges well with hot water, making sure to get into the crevices of the oranges as the recipe will use the rinds.
Cut your oranges in half. Then lay the orange flat side down, and then slice them very thin.
Place the sliced oranges, sugar and water in the Instant Pot.
Close the lid on Instant Pot and turn sealing valve to make sure it is in the CLOSED position.
Turn the Instant Pot to HIGH for 10 minutes. When the timer beeps, allow the Instant Pot to NATURAL RELEASE. The pin will drop and pressure will be fully released. This will take about 10 mintues or so.
Take the lid off the Instant Pot (it will easily come off if the NATURAL RELEASE process is complete, don't force it) and set your Instant Pot to SAUTÉ mode.
Caution: stir frequently as your sugar can burn. Continue to SAUTÉ marmalade until the temperature reaches 225°F. Use a candy thermometer to monitor the temperature. It should take about 25 minutes. Turn it off by pressing the CANCEL button.
Transfer your marmalade large bowl or canning jars and allow it to cool on the counter. You will see it setting up nicely. Once it has completely cooled, put a lid on it, and keep in the fridge for up to three months.
Storage: This recipe has you storing the Orange Marmalade in the refrigerator for up to 3 months. This is not a CANNING recipe where you will sterilize the jars and have the lids pops. Please don't store your marmalade in the pantry.Refrigeration: It's made with natural sugar from the oranges and regular sugar, so the odds of bacteria growing aren't too high. That's why it lasts so long. Runny or Watery Consistency: Basically, the marmalade can't set up properly if you don't heat it enough. It's important that it reaches 225 degrees or it's going to be watery or runny.Candy Thermometer: Use a candy thermometer to check the temperature of the marmalade. Don't overcook it for best results.Keep Stirring: You must stir the marmalade when you are sautéing. The sugar will burn really quickly if you don't.