Heat milk in a container on a medium-high flame.
Keep stirring it frequently until it starts steaming and is barely bubbling.
Register 180 degrees F on a candy thermometer.
Pour the milk into a clean container.
Stir it and keep checking the temperature until it is 110 degrees F.
Cover the container with a cloth to let it stay warm.
Place it undisturbed for at least 8-12 hours.