Makes 1 cup
Prep time: 3 hours
1 quart whole milk
1 1/2 cups sugar
1 vanilla bean, split and seeds scraped (substitute 1 tsp vanilla extract)
1/2 teaspoon baking soda
1) Combine 1 quart whole milk, 1 1/2 cups sugar, vanilla bean and seeds in a large, 4-quart saucepan and place over medium heat.
2) Bring to a simmer, stirring occasionally, until the sugar has dissolved.
3) Once the sugar has dissolved, add the baking soda and stir to combine.
4) Reduce the heat to low and cook uncovered at a bare simmer. Stir occasionally, but do not re-incorporate the foam that appears on the top of the mixture. Continue to cook for 1 hour. Remove the vanilla bean after 1 hour and continue to cook until the mixture is a dark caramel color and has reduced to about 1 cup, approximately 1 1/2 to 2 hours.
5) Strain the mixture through a fine mesh strainer.
6) Store in the refrigerator in a sealed container for up to a month.