A sweet staple of Latin American cuisine, dulce de leche (which literally translates as ‘sweet from milk’ or ‘sweet of milk’) is a delectable concoction of milk and sugar. Traditionally, it is made simply by heating up milk in a saucepan with a little sugar until the milk changes its consistency and color and becomes a gooey, viscous, light brown treat. However, it is also totally possible to make dulce de leche in a electric pressure cooker – so why not give it a try?
The science-y bit
One important thing that you need to know about dulce de leche relates to that almost magical change in color and texture. What is the trick that turns plain old runny white sweetened milk into something thicker and richer with a caramel hue? Well, this is where some science comes in handy (yes, the transformation from sweet milk to creamy dulce de leche is not magic at all, I’m sorry! but, the science is perhaps even more exciting than any magic could be).
Dulce de leche is made using something known as The Maillard Reaction. The Maillard Reaction describes a change in color and flavor which occurs when sugar reacts with amino acids (proteins) in foods. In simple language, it can be described as the ‘browning’ and ‘sweetening’ that you notice when you heat up marshmallows, bread or popcorn and they acquire a light brown color and a sweet, toasty taste. The Maillard Reaction is the reason why, when you simmer milk and sugar together there comes a point where the mixture goes brown, thick, sweet and slightly ‘toasted-caramel’ in taste.
As you may have guessed, The Maillard Reaction requires heat to work, and this is where your pressure cooker comes in! You need to be able to get the heat just right so that the Maillard Reaction occurs and the milk and sugar you pour into your pressure cooker convert into dulce de leche.
Thankfully, it is actually pretty easy to make dulce de leche in a pressure cooker. What you need to remember is that you should mix the milk and sugar together first (say about one tablespoon of sugar per cup of milk – though you can vary to suit your taste) until the sugar is completely dissolved. Then, pour the mixture in to your pressure cooker and turn the cooker up to a medium heat. Now, the mixture will begin to reduce – you want to wait until it has reduced to about a 6th of its original volume, and is a light brown hue. And voila! You have made dulce de leche.