Remove the label from an unopened can of sweetened condensed milk
Place the sealed can in a large pot
Cover the can with at least 2 inches of water
Bring the water to a gentle simmer
Keep the can fully submerged at all times
Simmer for 2 to 3 hours for light caramel
Simmer for 3 to 4 hours for darker caramel
Add more hot water as needed to keep the can covered
Turn off the heat
Let the can cool completely in the water before opening
Open the can only after it is fully cooled
Stir the caramel until smooth
Use immediately or transfer to a container for storage