Start by rinsing the blueberries under cold water if you're using fresh ones. If using frozen, there's no need to thaw them; simply measure them out directly.
In your Instant Pot, add the blueberries, 1 cup of water, lemon juice, and granulated sugar. Stir well to combine all the ingredients.
Secure the lid on your Instant Pot, ensuring the valve is set to the sealing position. Select the manual or pressure cook setting and set the timer for 5 minutes.
Once the cooking time is up, carefully perform a quick release by moving the valve to the venting position. Be cautious of the hot steam!
In a mixing bowl, whisk together the cornstarch and 2 tablespoons of water to create a slurry. Turn the Instant Pot to the sauté setting and add the slurry to the blueberry mixture. Stir constantly for about 2-3 minutes until the jam thickens to your desired consistency.
If you’re using vanilla extract, stir it in now for added flavor. Remove the pot from heat.
Carefully transfer the jam to a clean jar, allowing it to cool completely before sealing. Store the jam in the refrigerator for up to two weeks, or process in a water bath for longer storage.
