Dulce de leche is a type of sweetened milk caramel originating from South America. In the UK, we usually make dulce de leche by boiling cans of condensed milk. This process however, can be dangerous because if the pan boils dry the can will overheat and explode. Cooking the condensed milk sous vide prevents this from being a problem.
Preheat the water bath to 85°C
Transfer the contents of a can of condensed milk to a vacuum bag and seal
Place the bag in the water bath to cook for 10 hours. (If you prefer a darker caramel continue cooking)
The caramel will keep in the fridge for a few weeks
It is also possible to cook the condensed milk in the can or in a sterilised jar in the water bath. If doing this, the dulce de leche will keep for much longer.
For a luxury version, scrape the seeds of a vanilla pod in with the condensed milk before cooking.