Step 1

Stir together whole milk and sweetened condensed milk in pot of a programmable pressure multicooker (such as Instant Pot). (Times, instructions, and settings may vary according to cooker brand or model.) Select SAUTÉ setting, and select HIGH temperature setting. Cook, stirring occasionally, until mixture registers 180°F on an instant-read thermometer, 12 to 16 minutes. Press CANCEL.

Step 2

Fill a large pot with ice to a depth of 2 inches, and add water to cover. Alternatively, fill a sink with 2 inches of cold water. Remove pot from multicooker, and place in cold water. Let cool, stirring occasionally, until yogurt mixture registers 110°F, 3 to 5 minutes.

Step 3

Place yogurt in a medium bowl, and gradually whisk in about 2/3 cup warm milk mixture to temper yogurt. Stir tempered yogurt mixture into remaining warm milk mixture in pot. Wipe outside of pot dry, and reinsert in cooker. Cover cooker with lid, and lock in place. Turn steam release handle to SEALING position. Select YOGURT setting, and set for 8 to 10 hours. (10 hours yields a tangier yogurt.) When cooking pro- gram finishes, cooker will automatically turn off and keep yogurt at a safe temperature up to 2 hours.

Step 4

Remove lid from cooker. Place a fine wire-mesh strainer over a large bowl or an 8-cup liquid measuring cup, and pour yogurt through strainer, leaving any skin or thicker clumps in bottom of cooker. Stir mixture in strainer to strain until completely smooth. Transfer smooth yogurt to serving or storing jars. Refrigerate until cold and slightly thickened, about 4 hours.