Essential Custard Ingredients

Whole milk is 3½ percent fat, compared to skim milk, which must contain less than ½ percent fat. In testing, we found that custards and puddings made with skim milk were not by any means a disaster, but were nowhere near as rich and creamy as the desserts made with whole milk. Moreover, the desserts made with the higher-fat milks were thought to taste more decadent, with a distinct velvety texture. Fat is a flavor carrier, which would explain the boost in flavor. We always suggest using the type of milk specified in a recipe, so while skim milk probably won't ruin a recipe, whole milk and even 1 percent milk will make the recipe that much better. Whole milk is one of three milks we use in the Latin Flan in this class.

According to the U.S. Department of Agriculture, half-and-half must contain 10.5 to 18 percent fat. To find out how milk and half-and-half compared in recipes, we chose three test kitchen favorites that call for the latter—vanilla pudding, mashed potatoes, and shortcakes (minus the strawberries)—and prepared one batch of each with half-and-half and another with whole milk. Differences were most obvious in the potatoes, where the batch made with half-and-half was described as "much creamier," with a "smoother texture" and "more buttery flavor" than the batch made with milk. Though the vanilla pudding made with milk was looser than that made with half-and-half, flavor differences were slight. In dishes such as custards where you're looking for creaminess (not just fat and flavor), the differences will be notable although generally not unacceptable. We use half-and-half in addition to heavy cream in our Chocolate Pots de Crème for balanced richness.

In the dairy section of your grocery store, you’ve probably seen “heavy cream” as well as “whipping cream”—so what’s the difference? According to the U.S. government’s Code of Federal Regulations, heavy cream must consist of at least 36 percent milk fat, and whipping cream (sometimes also called light whipping cream) must be at least 30 percent but no more than 36 percent. This may not sound like much of a difference, but after whipping up more than a few bowls of cream, we learned that it can be. When making custards, it is important to use heavy cream when the recipe specifies, because the extra fat gives the custard a thick, luxurious texture. Pasteurized heavy cream, with a fat content of 40 percent (or 6 grams per tablespoon), is the best all-purpose cream to have on hand if you can find it. If not, the next best choice is ultrapasteurized heavy cream. We don’t recommend whipping cream. Heavy cream makes up the luscious base of the Crème Brûlée in this class.

This canned milk is made by heating pasteurized fresh milk in two stages to drive off nearly half of its water, which also triggers the Maillard reaction—a term for the browning that occurs when proteins and sugars break down, which creates a tremendous number of flavors. Once sealed in a can, the milk is sterilized to become shelf-stable, a process that triggers more browning and the creation of subtle caramel flavors. Evaporated milk isn’t sweetened, so we use it in conjunction with sweetened condensed milk in our flan.

Adding sucrose or glucose syrups to milk that’s been evaporated (and undergone Maillard browning) results in this canned milk. In combination with the lactose naturally present in the milk, these added sugars make up more than 50 percent of its weight, rendering sterilization unnecessary. Sweetened condensed milk is thick and rich, and while a whole can goes into our flan, if you happen to have leftovers from another recipe it’s delicious stirred into coffee or black tea.

Custards rely on the thickening power of egg yolks. The yolks also help to give the custards a luscious, rich texture. Unless otherwise stated, we use large eggs in all of our recipes. Check out the lesson on Custard Basics in this class to learn the science behind thickening with egg yolks—and how to avoid overcooking them.

Vanilla, in either bean or extract form, is used in numerous custards, puddings, and frozen desserts. For recipes such as crème brûlée, where the flavor of vanilla is key, we opt to use beans, as they provide a fuller aroma and more complex flavor than extract. Using both the pod and its seeds is key to maximizing the vanilla flavor; typically we steep the pod (along with the seeds) in warm dairy, then remove it before continuing with the recipe. Be sure to use fresh, plump pods for the best results. The beans should be moist and have a bit of sheen to them; avoid those that look like dried, shriveled twigs.