A favorite in Latin American countries, dulce de leche (sweet milk) is a thick, luscious, creamy dessert. Made by caramelizing sweetened condensed milk, it’s a delicious ice cream topping or filling for cakes or cookies.
Before this treat became so popular, ready-made dulce de leche was hard to come by, so people made their own. The traditional method involves simmering a can of condensed milk for several hours until it has thickened and caramelized to a rich amber hue. However, this method is risky, since built-up pressure can cause the can to explode. So we tested a couple of other cooking methods. In the end, we found that a double-boiler produces a great dulce de leche. It’s also faster than the in-can method, and you can see what’s happening as the milk cooks. If you want to make your own, start with three 14-ounce cans of condensed milk.
Fill the base pan of a double boiler (or a medium saucepan) halfway with water. Bring to a boil and then reduce the heat to medium for an active simmer. Pour the condensed milk into the double boiler’s top insert (or into a stainless-steel bowl that fits snugly on top of the saucepan) and set it uncovered over the simmering water. Every 30 minutes, check the water level in the pan, replenishing as needed, and give the milk a stir. Remove from the heat once the milk has caramelized and thickened, 2-1/2 to 3 hours.