- place a metal bowl over a large pot of water, the bowl should be suspended over the pot and should cover the pot so no steam excapes
- fill the pot with as much water as possible without spilling out after bowl is placed over top
- bring the water to boil over high heat, reduce to a strong simmer, set the bowl in place on top of the pot and pour the milk and sugar into the bowl. stir to combine and dissolve the sugar
- the milk needs to reduce for about 8 hours, as it cooks, scrape the sides and botom of the bowl often increasing frequency as the milk reduces. the color will turn from white to beige to carmel . after about 6 hours the milk will become viscous and require more frequent stirring.
- at hour 7 put a couple small plates into the freezer to cool. the culce de leche is ready wen it turns a deep caramel color and when the milk is so thick that it coats the spoon in a thick layer. test for doneness with the cold plate test, take a plate from freezer and drop 2 tsp of the dulce de leche onto the plate. wait for 30 seconds and tip the plate vertically. if the mixture stays in place its ready, if it runs on the plate keep reducing it further and test again.
- once it has reached tghe proper consistency, remove it from the heat, stir for 1 min to let it cool slightly then stir in the vanilla. pour into clean jars while it still hot, this will minimize air bubbles, it will store in fridge for at least 6 months