One of my favorite tools in my kitchen is my slow cooker. It lets me make full, delicious meals in the hot Nevada summer without heating up my kitchen. In the desert, this is a plus. One of my favorite things to make in my slow cooker is dulce de leche. A rich, creamy caramel with the most heavenly thick consistency. Most recipes ask you to place a can of condensed milk in a saucepan full of water and simmer for several hours. This is a terrible idea. Let me tell you why.
First, there is no way to keep that water at a low consistent temperature for several hours without standing by the stove the entire time with a thermometer.
Second, no one is going to stand by the stove for hours watching a thermometer.
Third, this method is a huge fire risk. You are leaving a pot of water over heat, probably unattended for part if not all of the cooking time, during which any number of things could start a fire.
Fourth, you are heating a pressure sealed can on the stove top. I guarantee that can will distend (swell up) under pressure, and if there is any flaw in the metal at all, you now have a hot, sugary, sticky bomb on your hands. Just don’t do it!
So how, may you ask, can we make dulce de leche at home, without the risk of bodily harm? With the slow cooker! A basic slow cooker will maintain a consistent temperature of about 200 degrees Fahrenheit. At this temperature, the contents of the can cook without ever reaching a temperature high enough to distend the can. You can safely start the process and walk away, just like any other slow cooker application.
Depending on how dark you like your caramel, you’ll cook your cans for different amounts of time. Shorter times equal lighter, softer caramels and longer times equal darker, firmer caramels.
In the photo above, the caramel on the far left was cooked for 8 hours, and let to cool to room temperature. It is a fairly thick caramel sauce at this point, with a creamy and mild flavor, with just a hint of fruitiness. This would be a good general purpose caramel. You would use it for anything that you would want a mild caramel flavor for.
The caramel in the center was cooked for 12 hours and cooled to room temperature. Its much thicker, and holds its shape much better. The flavor is less creamy, and more strongly caramel, with a slight tang at the end. Choose this for things that you want the caramel flavor to shine through, like in coffee, to dip apple slices, or as a topping for ice cream.
The caramel on the right was cooked for a whopping 14 hours. Its very firm, you can see the impression of the can in it! It has the strongest caramel flavor of the three, but is less complex and slightly bitter. You would want this if you were making something that was caramel flavored, like icing, pie, cake, or pudding. You probably want to warm and stir this caramel before you use it, to loosen it up.
Always let your cans cool at least an hour or more, because that hot caramel WILL come shooting out of the can if you don’t. Believe me, hot sugar burns are worse that any other kind of burn I’ve experienced.
Remove label(s) from the can(s) of condensed milk, but leave unopened. You can use as many cans as will fit in a single layer in your crock, without touching.
Place can(s) in the crock of your slow cooker and fill with enough water to cover by at least one inch.
Cover crock and set to low heat. Cook for 8-14 hours, depending on the darkness of the caramel desired.
Turn off cooker and use tongs to remove can(s) from the slow cooker. Place on a towel or hot pad to protect your countertops. Allow to cool completely before opening. (At least one hour)