Set the Instant Pot to Sauté on Less (low). When hot, add concord grape jelly, chili sauce, and water to the Instant Pot, and whisk together until combined. Cancel the sauté.

Stir in meatballs until well coated.

Close the lid, set the lid to Sealing, and set the Instant Pot to Pressure Cook on HIGH pressure for 5 minutes. It will take several minutes for the pot to come to pressure.

When the cook time is complete, allow the pressure to release naturally for 3 to 5 minutes, followed by a quick release. The 5-minute natural release will help prevent any liquid from sputtering out of the pressure release valve. Remove the lid and stir the meatballs.

OPTIONAL: To thicken the grape jelly sauce, set the pot to Sauté on Normal for about 5 minutes to reduce the sauce. For an even thicker sauce, create a cornstarch slurry by stirring together the cornstarch and cold water. Set the pot to Sauté, add the cornstarch mixture to the meatballs, and simmer until the desired consistency is reached.

Tip: If transferring the meatballs to a serving tray or party platter, pour the extra sauce over top of the meatballs or pour it into a large ramekin as a dipping sauce.