Make sure the Instant Pot inner pot is clean and completely dry. If you’ve recently cooked strong flavors like chili, remove the sealing ring or use a separate “sweet” ring for dairy to avoid off-odors.

Pour the gallon of milk into the inner pot and close the lid (vent position does not matter for the yogurt function). Press Yogurt, then Adjust or Mode until the display shows “Boil” or “More,” depending on your model. The Instant Pot will heat the milk to about 180–185°F (82–85°C) to denature the proteins for thicker yogurt. This usually takes 30–45 minutes and the pot will beep when it’s done.

Open the lid carefully and whisk the hot milk to even out the temperature and prevent a skin from forming. Use an instant-read thermometer to confirm the milk has reached at least 180°F (82°C). If it has not, turn on Sauté on low and heat gently, whisking constantly, until it does. Turn off Sauté once the temperature is reached.

Remove the inner pot from the Instant Pot base to speed cooling. Let the pot sit on the counter for 30–45 minutes, or place it in a sink with a few inches of cool water around the outside, whisking occasionally. Cool the milk to 110–115°F (43–46°C), warm but not hot. If you don’t have a thermometer, the sides of the pot should feel warm but comfortable to hold.

If using nonfat dry milk powder for thicker yogurt, whisk 1/4 cup into the warm (110–115°F) milk until completely dissolved and smooth.

In a small bowl, add 2–3 tablespoons of plain yogurt with live active cultures. Ladle in about 1 cup of the warm (not hot) milk and whisk until completely smooth. This gently warms and loosens the starter so it distributes evenly.

Pour the tempered yogurt mixture back into the inner pot of warm milk. Whisk gently but thoroughly so the cultures are evenly distributed without creating too much foam.

Return the inner pot to the Instant Pot base and close the lid. Press Yogurt again and set the incubation time for 8–12 hours at around 110°F. Choose 8 hours for mild, creamy yogurt, 10 hours for medium tang, or 12 hours for tangy and thicker yogurt. Avoid moving or jostling the pot during incubation. The Instant Pot will beep and display “Yogt” or “End” when the cycle is finished.

Open the lid gently and look at the surface. The yogurt should appear set and slightly jiggly, similar to a soft custard. A small amount of clear liquid whey on top is normal. For the smoothest texture, do not stir at this stage, as stirring will release more whey.

Cover the inner pot with a lid or plastic wrap and refrigerate the yogurt for at least 4 hours, preferably overnight. This chilling time helps the yogurt thicken further and allows the flavor to mellow. After chilling, gently spoon the yogurt into jars or storage containers.

For thicker, Greek-style yogurt, line a large mesh strainer with cheesecloth, a clean thin dish towel, or coffee filters and set it over a bowl. Pour some or all of the chilled yogurt into the lined strainer. Refrigerate and let drain for 2–4 hours, depending on desired thickness. Transfer the thickened yogurt to containers and reserve or discard the liquid whey as desired.

Keep the bulk of the yogurt plain for versatility and to use as starter for future batches. Sweeten individual portions right before serving by stirring in honey, maple syrup, or sugar, plus vanilla extract and a tiny pinch of salt if desired. You can also add fruit, jam, or spices like cinnamon or cardamom.

Transfer the finished yogurt to jars or airtight containers and refrigerate for 10–14 days. Save about 1/2 cup plain yogurt from this batch (within 7–10 days) to use as the starter for your next Instant Pot yogurt.