Dulce de Leche
4 cups whole milk
3/4 cup granulated white sugar
2 tablespoons light corn syrup
1/2 teaspoon baking soda
1/8 teaspoon salt
1 teaspoon pure vanilla extract
Put the milk, sugar, corn syrup, baking soda and salt in a large, heavy-duty 8 quart (8 liter) saucepan or Dutch oven. THIS IS IMPORTANT!! The milk will foam at least twice in size so you need a large pot so it doesn't boil over. Place over medium to medium-high heat and bring just to a boil. Watch carefully, and as soon as the milk begins to foam up, stir with a heatproof spatula or wooden spoon, and reduce heat until the milk is just at a low rolling boil. (If the milk foams up too much, remove the saucepan from the heat until the foam starts to subside. Then return to heat.)
Continue to cook the milk, stirring the bottom and sides of the saucepan frequently, until the mixture becomes very thick and sticky and caramel colored (this will take about 40 - 60 minutes). It is important to frequently stir the milk so it does not burn. Adjust the heat as necessary, you want the milk to be at a low rolling boil.
Note: There are several stages the milk goes through during the cooking process. When the milk first comes to a boil there is a lot of foam. Eventually the foam subsides and after about 15 minutes, you will notice that the milk turns a light beige color. As it continues to cook, the milk thickens and gets darker and darker in color. The more you cook the Dulce de Leche, the thicker and more caramel colored it will become. Once the Dulce de Leche has been reduced to about 1 1/4 cups it is ready. Remove from heat. Stir in the vanilla extract. Let cool before covering and storing. The Dulce de Leche can be stored in the refrigerator for at least a month.