Dulce de Leche from Condensed Milk

Before you start

Dulce de leche is milk and sugar cooked slowly until the sugars and milk proteins brown into a thick, caramel-colored spread. It is beloved across Latin America, where it fills alfajores and layers cakes, and it is easiest to make at home from sweetened condensed milk, which has already done half the work.

You will see recipes that simmer the unopened can in water for hours. Do not do this. A sealed can heated in water can build pressure and burst, spraying scalding contents, especially if the water level drops. The method here is safer and gives you more control: pour the condensed milk into an open baking dish, cover it with foil and bake it in a water bath, checking color and thickness as you go. The longer it cooks, the darker and thicker it becomes, so you can stop at a light, pourable stage or carry on to a deep amber, spreadable one.

Ingredients

• 1 can (397 g / 14 oz) sweetened condensed milk — not evaporated milk
• Pinch flaky sea salt — or ⅛ tsp fine salt
• ½ tsp vanilla extract — optional
• As needed hot water — for the water bath

Method

1. Heat the oven to 220°C (425°F) with a rack in the middle. Boil a kettle of water.
2. Pour the condensed milk into the pie dish, scraping the can clean, and sprinkle with the salt. Cover the dish tightly with foil, crimping it around the rim.
3. Set the pie dish in the roasting pan, place it in the oven and carefully pour hot water into the roasting pan until it comes halfway up the sides of the pie dish.
4. Bake for 60 to 90 minutes, checking every 30 minutes. Lift a corner of the foil away from you to avoid steam. Top up the water bath with hot water whenever it drops by a third.
5. The dulce de leche is ready when it is a caramel brown and thick enough to mound on a spoon. At 60 minutes it is usually light tan and pourable; at 80 to 90 minutes it becomes darker and much thicker.
6. Lift the pie dish out of the water bath with oven mitts, remove the foil and let it cool for about 30 minutes. The surface may look lumpy or set.
7. Whisk vigorously, adding the vanilla if using, until smooth and glossy. Transfer it to a clean jar. It thickens further as it cools.

Tips for success

• Glass and ceramic dishes cook more gently than metal and are less likely to scorch the edges.
• If it is thicker than you want, whisk in a tablespoon of warm milk at a time to loosen it.
• For a very smooth texture to fill alfajores, whisk it while still slightly warm, or blend it briefly with an immersion blender.

Substitutions

Sweetened condensed milk

For a version from scratch, simmer 1 liter (4 cups) whole milk, 300 g (1½ cups) sugar and ¼ tsp baking soda in a wide pan, stirring often, for 2 to 2½ hours until thick and caramel colored. It has a more complex flavor and takes constant attention.

Cow's milk condensed milk

Sweetened condensed coconut milk works with the same method, giving a coconut-flavored spread that browns more slowly.

Oven method

Cook the condensed milk in a heatproof bowl set over a pot of simmering water, covered, for 1½ to 2 hours, stirring every 20 minutes and topping up the water.

Variations

Cajeta-style with goat's milk

Use the from-scratch method with goat's milk in place of cow's milk for a tangier caramel sauce.

Spiced dulce de leche

Add a cinnamon stick to the dish before baking and remove it before whisking.

Troubleshooting

It is still pale after 90 minutes

The oven may run cool or the water bath is too deep. Check the oven with a thermometer and continue baking in 15-minute stages.

Lumpy or grainy texture

This is common as it cooks. Whisk hard while it is still warm, or use an immersion blender; a few seconds is enough.

Dark edges or a bitter taste

The dish was too close to the heat or the water bath ran dry. Keep the water halfway up the dish and check it every 30 minutes.

Storage

Refrigerate in a covered jar for up to 2 weeks. It firms up when cold; warm it gently in a water bath or the microwave in short bursts and stir. Discard it if it develops an off smell or mold.

Safety notes

Never heat an unopened can of condensed milk in water, in a slow cooker or in the oven: sealed cans can burst. Use oven mitts with the hot water bath. Contains milk.