01 - Pour the milk into a saucepan and warm gently over medium heat, stirring occasionally, until it reaches 185°F (85°C). Do not allow the milk to come to a boil.
02 - Remove the saucepan from heat and let the milk cool to between 110°F and 113°F (43–45°C). Use a kitchen thermometer for accuracy.
03 - In a small bowl, combine the yogurt starter with a few tablespoons of the cooled milk, whisking until completely smooth.
04 - Return the starter mixture to the saucepan with the remaining cooled milk. Stir thoroughly to ensure even distribution of the cultures.
05 - Pour the inoculated milk into a clean container or divide among individual jars. Cover loosely with lids.
06 - Place the containers in a warm environment — such as a turned-off oven with the interior light on or a dedicated yogurt maker — and let incubate for 8 to 12 hours, or until the yogurt reaches your preferred consistency and level of tanginess.
07 - Transfer the set yogurt to the refrigerator and chill for at least 2 hours before serving to allow it to firm up properly.
08 - Keep refrigerated. The yogurt will stay fresh for up to 1 week.