Add the cold water, milk and butter to your Instant Pot’s inner pot.
Add husked corn on the cob to the Instant Pot.
Cook on High Pressure for 2-3 minutes. Allow the Instant Pot to release the pressure naturally after the cook time is up. Remove the corn cobs from the Instant Pot, transfer them to a serving platter, rub with butter, then add sea salt and black pepper to taste.