A couple of readers reported an unpleasantly graininess when they tried my dulce de leche from Chewy Gooey Crispy Crunchy Melt-In-Your-Mouth Cookies. I had good results when I tested for the book, so I was curious about the feedback. I made the recipe several times in the last few days, paying close attention to what might be going on.
Before I get into the details, let me admit that the recipe takes more like 60-90 minutes than the optimistic 45 minutes that I said it would take. And, you might as well use a bigger pot than I called for so that the mixture won’t flow over the moment you turn your back.
About the texture, it turns out that tending the pot and stirring frequently is critically important for a smooth sauce. You must stir any foam into the sauce regularly, as well as scraping the bottom and corners of the pot and around the sides, continually incorporating any thickened sauce from the sides and corners of the pot into the rest of the sauce before those thickened parts congeal and toughen. As the sauce thickens towards the end of the cooking, you must stir more often, and then constantly. I use a silicon spatula mostly, but have also used a whisk, though the whisk tends to cause more foam and if you whisk briskly the finished dulce will be lighter in color and texture, which may or may not be what you want. I’ve revised the recipe below with greater emphasis on stirring and with the additional step of straining the finished sauce for a little extra smoothness insurance. And I’ve added a pat of butter…
In one of my samples I ran out of whole milk and had to top off the measure with less than ¼ cup of non-fat milk. So, I added maybe a tablespoon of heavy cream to compensate. It seemed like a negligible amount so I promptly forgot about it. Comparing samples later, I liked the texture of that one best. I concluded that I had just been more careful about stirring. But later, I remembered that tiny bit of cream and wondered if such a small amount of extra fat could have softened the proteins (or something?). So I tested again with whole milk and but added a tablespoon of butter. I got the smoothest sauce of all... Of course I also tended the pot as though it were a baby. Clearly this is a recipe to make when you have time or other things going on in the kitchen meanwhile.
DULCE DULCE DE LECHE
(Revised from Chewy Gooey Crispy Crunchy Melt-In-Your-Mouth Cookies)
Makes 1 generous cup
½ vanilla bean
1 quart whole milk
1 tablespoon butter
½ cup (3.5 ounces) sugar
½ teaspoon baking soda
Pinch of salt (optional but really good...)
Set a fine or medium fine strainer over a heatproof bowl.
With a sharp paring knife, cut the vanilla bean in half lengthwise. In a large heavy bottomed pot (that holds at least 6-quarts) combine the vanilla bean pieces with the milk, butter, sugar, baking soda, and salt. Bring the mixture to a simmer, stirring frequently, especially around the sides of the pot. At first the milk will foam dramatically, and it may curdle, but will eventually smooth out. Continue to cook, frequently stirring in any foam on top and sweeping the sides, corners, and all over the bottom of the pot with a silicone spatula. Keep the mixture boiling briskly but not furiously without letting it overflow. The mixture will gradually turn a deep caramel color as it thickens. This may take from 60-90 minutes, depending on your stove and the size of your pot. The mixture becomes especially bubbly and foamy in the last stages of cooking: adjust the heat so that it bubbles actively but not violently and stir it very frequently, and then constantly (especially around the sides and corners of the pot) until done. It is done when the mixture is reduced to a generous cup and a little spooned over an ice cube thickens to a soft gel. Scrape the sauce into the strainer and stir and press it through. Be sure to scrape the sauce from underneath the strainer into the bowl. Cool the sauce slightly, then taste and adjust the salt. You can put the spent pieces of vanilla bean back into the mixture if you like. They will either keep on giving flavor or at least look as though they are. May be kept in a covered container in the refrigerator for at least 1 month