Make sure the Instant Pot is clean. Pour the milk into the Instant Pot.

Close the Instant Pot lid and set it to the "Yogurt" setting. Adjust the temperature to "Normal" and press "Boil." This will heat the milk to around 180°F.

Once the boiling cycle is complete, open the lid and let the milk cool down to about 110°F.

In a small bowl, mix the 2 tablespoons of plain yogurt with a small amount of the cooled milk to create a smooth mixture. Add the yogurt mixture back into the Instant Pot with the rest of the cooled milk. Gently whisk to ensure even distribution of the starter culture.

Close the Instant Pot lid again. Set the Instant Pot to the "Yogurt" setting and adjust the time to 4-8 hours for fermentation. The longer you let it ferment, the thicker and tangier the yogurt will be.

After the incubation period, open the lid and check the yogurt. It should be thickened and have a tangy flavor. If it's not thick enough, you can let it incubate for a few more hours. Keep in mind that the yogurt will get thicker as it sets and chills.

Once the yogurt is done, transfer it to glass jars or containers with lids. Refrigerate for at least 4 hours to chill and further set the yogurt.