Step 1

Fill the sous vide machine with water to just below the max fill line. Begin preheating the water to 185 degrees.

Step 2

Pour the sweetened condensed milk into your clean jars, leaving about 1 inch of head space. Place the lids tightly on the jars.

Step 3

Immerse the jars in the water. Add more water if needed to cover the tops of the jars, but do not fill over the max fill line.

Step 4

Cook for 15 hours, or until the sweetened condensed milk is thick, with a dark caramel color.

Step 5

Remove the jars from the water bath and cool to room temperature. Dulce de leche will keep in the refrigerator for up to 3 months.