Peel the label off the can (or cans!) of sweetened condensed milk, place it in a pot or large saucepan, and cover it with water by 1 to 2 inches. Bring it to a very gentle boil, then reduce the heat to LOW, so that the water has a nice slow simmer.

VERY IMPORTANT: Watch the water level and add water if the level of water falls below the top of the cans. Very important to keep a watch on the water level!

Simmer the can(s) for 2 to 2 1/2 hours for a lighter golden dulce de leche. Simmer it/them for 3 1/2 hours for a deeper color and flavor. (Using tongs, VERY CAREFULLY turn over the cans halfway through the simmering process.)

After the simmering time, turn off the heat and allow the cans to come to room temperature.