Remove the label from your cans and remove as much of the glue as possible.
Place the cans in a large pot and add enough water to the pot to cover the cans by 2 inches.
Bring the water to a low boil over medium-high heat. Then, reduce the heat to its lowest setting and let simmer for 3 1/2 hours. It’s important to make sure the cans are fully submerged at all times, adding additional water if needed during the cooking process. I like to cover my pot to cut back on the evaporation.
Remove the pot from the heat and leave the cans in the water. Let the water in the pot and the cans come to room temperature. Be careful: Opening the cans while still hot can cause sputtering and burns.
Store the cans in the refrigerator. Unopened cans will last up to three months. Once opened, the dulce de leche will last about one week in the fridge.