A reader, Pam, "delurked" yesterday to ask for clarification about putting together a custard. When to use butter; when not to use butter. She also said (tongue in cheek, I hope) that she was afraid that I would tap my foot disapprovingly and ask her why she hadn't been paying attention all along. Well, fear not, Pam. I have decided that I am just not that person. A few months ago, before I started this wee blog and before I started truly understanding the level of hesitancy out there when it comes to cooking, I made the conscious decision not to be the food snob who rolls their eyes at folks who think foie gras sounds "icky," or to smugly smirk when someone tells me that their favorite restaurant is Chili's. I have given myself the job of demystifying recipes, not denigrating those who try to follow them.
In my current kitchen view, a recipe is a list of ingredients that has been stapled to a description of the technique/techniques for combining said ingredients. So, to avoid confusion, I thought I'd give you a bit of a technique primer.
Puddings and Custards
Custards are thickened with the power of eggs. Some use yolks, some use whole eggs, some use a mixture of yolks and eggs. Regardless, unless it contains eggs, it's not technically a custard. Since eggs are so versatile, there are lots of ways to cook them. On their own, scrambled, poached, coddled, fried, baked, hard cooked all come to mind. But when used as one ingredient in a custard, the way the eggs set up determines the style of the custard. If you stir and cook a custard to its maximum thickness on the stove top, it's called a stirred custard. If you pour the custard into a mold of some sort and then bake it, it's called a baked or "still" custard. And, in the US, if the custard contains starch, we call it pudding. In France, a starch based custard is pastry cream or crème pâtissière. Still custards are generally the most firm, followed by starch-thickened custards and stirred custards.
The first thing you need to figure out is if the custard has starch in it. Any ingredients like flour, corn starch, arrowroot, etc are starches and lend their thickening power to the custard. If the ingredient list does contain starch, understand that you will have to fully cook the custard on the stove. This means that you must bring it to a boil and stir it like a crazy person for about 30 seconds. This is because most starches aren't completely activated--swollen up and gelatinized--until they reach boiling temperature. If your recipe calls for starch, make sure you bring it to a boil. If you've ever made pudding that tastes kind of chalky, it's because you didn't get it hot enough.
If the ingredient list doesn't contain starch, the next step is to see decide if the custard is a stirred custard or a baked/still custard. If you're making crème brûlée, you'll be baking the custard in the oven, so it's a still custard. If you're making egg nog or Creme Anglaise or ice cream base, the custard will be fully cooked on the stove top, so it's a stirred custard. The procedure for each will be almost identical, but you won't continue to cook a base for a still custard after you temper in the eggs.
Custards with starch (American-style pudding)
- Whisk together dairy and half the sugar in a sauce pan.
- Whisk together the eggs/yolks with the rest of the sugar, salt and dry ingredients, including the starch. If the ingredient list doesn't contain salt, ignore it and add some anyway. Some recipes won't contain eggs. That's fine, but you can always add in a yolk or two for richness.
- Bring dairy mixture up to just below a boil.
- Add hot dairy, a bit at a time, to the egg mixture, whisking madly. This brings the temperature of the eggs up gradually and prevents you from scrambling your eggs.
- Pour everything back into the pot. Over medium heat, whisk madly until the mixture comes to a boil. Boil for about 30 seconds.
- Strain mixture through a fine mesh strainer. If the recipe calls for butter, chopped chocolate and/or an extract or liqueur, add it/them now and whisk in until smooth.
Custards without starch (this goes for curds, too--curds are just citrus based custard, as opposed to dairy-based)
- Whisk together dairy and half the sugar in a sauce pan.
- Whisk together eggs/yolks with the rest of the sugar and the salt. If your ingredient list doesn't contain salt, add it anyway.
- Bring dairy (or citrus) mixture up to just below a boil.
- Add hot dairy/citrus, a bit at a time, to the egg mixture. Gee, doesn't all of this sound oddly familiar?
- At this point, if you're making a still custard, as for crème brûlée or flan, just strain the mixture, pan it up and bake in a water bath at about 275F. If you're making a stirred custard, keep going:
- Pour the egg mixture back into the pot. Over medium-lowish heat, stir the custard/curd until the mixture thickens and coats the back of a spoon. This happens at around 160F. At this point, you'll want to cool the custard quickly so it won't curdle. You can strain it into a metal bowl set in an ice bath and whisk, or you can hold out a portion of the dairy to add back in at the end of cooking. Your choice, but strain the mixture either way.
- If you're making curd, whisk in the butter after straining.
Double Boiler method
You can make a custard or curd in a double boiler. If you want to use the double boiler method, add everything except the butter to the top pan/metal bowl. Keep water at a gentle simmer, and whisk constantly until the custard/curd has thickened. Strain and stir/whisk in butter. I wouldn't bother using a double boiler with a starch-thickened custard, though. The starch helps prevent curdling, so you should be fine cooking over direct heat. The double boiler method is good for custards that you want to thicken but not boil.
Okay, pop quiz. I give you an ingredient list, you give me the method you'd use to put it together.
Exhibit A (Anglaise)
1 cup heavy cream
2 teaspoons vanilla extract
4 egg yolks
1/3 cup white sugar
pinch of salt
Exhibit B (Chocolate Pudding)
3/4 cup (150 grams) granulated white sugar
3 tablespoons (30 grams) cornstarch
1/3 cup (30 grams) Dutch-processed cocoa powder
1/4 teaspoon salt
2 1/2 cups (600 ml) whole milk
1/2 cup (120 ml) heavy whipping cream
4 large egg yolks
4 ounces (120 grams) semisweet chocolate, finely chopped
1 1/2 teaspoons pure vanilla extract
1 tablespoon (14 grams) unsalted butter, room temperature (cut into small pieces)
Exhibit C (Flan)
2 cups heavy cream
1 cinnamon stick
1 vanilla bean, split and scraped
3 large eggs
2 large egg yolks
Okay, this one isn't an exhibit, really, It's a question: Which of the three recipes might you want to use a double boiler for? Why?
You all did very well today. Don't forget to pick up your custard-genius certificate on your way out.