by Jeff Potter
When it comes to folding egg whites into a batter, as long as you’re using a whisk or spatula—not an electric mixer—you can be a bit more vigorous than conventional wisdom suggests.
Soft peak stage: the foam stays on the whisk but the peak falls over.
Firm and stiff peak stages: the foam maintains its shape and can be sculpted.
French and Italian Meringue
There are two general forms of meringues: those in which the sugar is directly added as the egg whites are whisked (French Meringue), and those in which the sugar is dissolved before the egg whites are whisked (Swiss and Italian Meringue—we’ll cover Italian here, but they’re similar). The French version tends to be drier (sugar is hydroscopic, sucking the moisture out of the whites—this is why it increases viscosity) and also grittier; the Italian version has a smoother, almost creamy texture.
French Meringue
In a clean bowl, whisk 3 egg whites to soft peak stage.
Add ¾ cup (150g) of sugar—preferably super-fine sugar—one tablespoon at a time, while continuously whisking. If using regular sugar, you’ll need to whisk longer to make sure the sugar is entirely dissolved. To check, roll a little bit of the meringue between two fingers (it shouldn’t feel gritty).
Italian Meringue
Create a simple syrup by heating in a saucepan ½ cup (100g) sugar and ¼ cup (60g) water to 240°F / 115°C. Set aside.
In a clean bowl, whisk 3 egg whites to soft peak stage. Slowly pour in sugar syrup while whisking continuously.
Meringue Cookies
To make meringue cookies, start with either egg-white meringue recipe. Optionally fold into the meringue whatever ingredients you’d like—ground almonds, chocolate chips, dried fruit, cocoa powder.
Using a spoon or piping bag, portion the meringue onto a cookie sheet lined with parchment paper. Bake in an oven preheated to 200°F / 95°C for a few hours, until they freely come off the parchment paper.
No piping bag? No problem. Put your filling in a large resealable bag and snip off one of the corners. You can use Italian meringue as a topping on desserts as well.
Chocolate Port Cake
One of the great things about this chocolate port cake—besides the chocolate and the port—is the recipe’s wide error tolerances. Most foam cakes—those cakes that rely on a foam to provide the air—are very light (think angel food cake). The reason this recipe is so forgiving is that it uses a foam without trying to achieve the same lightness.
You’ll need a small saucepan, two clean bowls, a whisk, and a round baking pan or springform pan, 6–8″ / 15–20 cm.
In the saucepan (over a burner set to low heat), melt and mix together, but do not boil:
½ cup (125g) port (either tawny or ruby)
½ cup (114g) butter
Once butter is melted, turn off heat, remove pan from burner, and add:
3 oz (85g) bittersweet chocolate, chopped into small pieces to facilitate melting
Leave the chocolate to melt in the port/butter mixture.
In two bowls, separate:
4 large (240g) eggs
Make sure to use a clean glass or metal bowl for the egg whites, and be careful not to get any egg yolk into the whites.
Whisk the egg whites to stiff peaks.
In the bowl with the egg yolks, add:
1 cup (195g) granulated sugar
Whisk the egg yolks and sugar together until thoroughly combined. The yolks and sugar should become a slightly lighter yellow after whisking for a minute or so. Pour the chocolate mixture into the egg yolk/sugar mixture and whisk to thoroughly combine.
Using a flat wooden spoon or flat spatula, add to the chocolate mixture and fold in (but do not overstir!):
¾ cup (100g) all-purpose flour
Then fold in the egg whites in thirds. That is, transfer about a third of the whisked egg whites into the chocolate mixture, mix together, and then repeat twice more. Don’t worry about getting the whites perfectly incorporated, although the batter should be relatively well mixed together.
Grease your cake pan with butter and line the bottom with parchment paper, so as to make removing the cake from the pan easier. Transfer the mix to the cake pan and bake in an oven preheated to 350°F / 175°C until a toothpick or knife, when poked into the center, comes out clean, around 30 minutes.
Let cool for at least 10 to 15 minutes, until the edges have pulled away from the sides, then remove from pan. Dust with powdered sugar (you can use a strainer for this: place a few spoonfuls of powdered sugar in the strainer and then jog it with your hand above the cake).
Note
When working with chocolate in baking, don’t just substitute, say, 80% bittersweet chocolate for a semisweet bar. In addition to differences in sugar, the two types of chocolate have different quantities of cocoa fat, and recipes that rely on the fat level will need to be adjusted accordingly.
Optimal Cake-Cutting Algorithm for N People[3]
If you grew up with a brother or sister, you’re undoubtedly familiar with the technique for avoiding fights when splitting food: one person divides it, and the other person chooses. ("You can halve your cake, and eat it, too!") But what to do if you have more than one brother or sister?
There is a solution, but it’s a bit more involved. Here’s the algorithm for cutting a round cake for N people. It’s not perfect—don’t use this for negotiating land divisions after minor land wars—but when it comes to a table of kids and a large chocolate cake, it’ll probably work. (If you find yourself cutting cake for hardcore math geeks, however, I suggest reading up on the literature. Start with An Envy-Free Cake Division Protocol—http://www.jstor.org/pss/2974850—and plan to be at it for a while.)
Only one person actually does any cake-cutting, and that person can either be a cake-eater or just a referee. Start with the cake in front of you, along with a knife and N plates. Proceed as follows:
Make a first cut in the cake, as normal.
Explain that you’re going to slowly hover the knife above the cake while moving it clockwise around the cake, just like someone thinking about how big the next slice should be. Anyone—including the person cutting the cake—can say "stop" at any point to declare that they want a piece that size, at which point, that’s where you’ll cut the next slice.
Slowly move the knife above the cake until someone calls stop.
Slice the cake and hand the person who called stop the new slice. Continue with step 3 with the remaining cake eaters. (To be clear, anyone who calls "stop" is now out of the negotiation and doesn’t get to call it again.)
When you’re down to just one last person, cut the cake wherever he or she likes, which may leave a leftover piece.
One of the nice things about this protocol (a protocol is similar to an algorithm, but allows for accepting user input after being started) is that it allows people who for whatever crazy reason want small slices to do so, and gets them out of the way at the beginning, meaning if somebody else wants a larger slice than an equal N division would allow, they get more cake and can eat it, too.
If someone is being greedy and wants a too-big piece, they’ll end up getting the last slice—which will normally be the largest slice. If two or more people end up being greedy, though, they could allow the referee to reach the end of the cake by never calling stop, in which case I suggest eating the cake yourself. There’s no guarantee that this protocol will satisfy everyone—just that the honest actors are protected from the dishonest ones.
Egg Yolks
If Eskimos have N words for describing snow, the French and Italians have N+1 words for describing dishes involving egg yolks. A number of these dishes use egg yolks to create light, airy foams by trapping air bubbles.
Egg yolks are much more complex than egg whites: ~51% water, ~16% protein, ~32% fat, and ~1% carbohydrates, while egg whites are only protein (~11%) and water. In their natural state, egg yolks are an emulsion.
Note
An emulsion is a mixture of two
liquids that are immiscible—that is, unable to mix (think oil and water). Mayonnaise is the classical culinary example. Egg yolks are an emulsion, too: the fats and water are held in suspension by some of the proteins, which act as emulsifiers—compounds that can hold immiscible liquids in suspension. For more on the chemistry of emulsions, see Colloids in Chapter 6.
Like egg-white foams, egg-yolk foams trap air with denatured proteins that form a mesh around air bubbles. Unlike whites, though, the only way to denature the proteins in the yolk is with heat; the optimal temperature for egg-yolk foam creation is 162°F / 72°C. Too hot, though, and the proteins coagulate, leading to a loss of air and affecting the texture.
Extra Leavening
Some recipes rely on more than just one method of incorporating air into food. Some English muffins and Chinese pork buns, for example, use both yeast and baking powder. Waffle recipes often call for both whipped egg whites and baking powder. And some mousse recipes call for both whipped egg whites and whipped cream. If you find that a recipe isn’t turning out as light as you’d like, look to see if other methods of leavening can be added. If a recipe doesn’t rely on chemical leaveners, adding a small amount of baking powder is usually a safe bet. Or, if the recipe has eggs, try separating some of the eggs, whisking the whites, and folding the egg-white foam into the batter.
Simple White Wine and Cheese Sauce
This sauce needs very few ingredients and not much in the way of equipment—a whisk, a bowl, and a stovetop—making it an easy impromptu dish even in an unfamiliar kitchen. (For more on sauces, see Béchamel Sauce (White Sauce) of Chapter 3.)
The only tricky part is preventing the eggs in this sauce from getting too hot and scrambling. If you have a gas burner, this can be done by moving the saucepan on and off a flame set to very low heat. Position yourself so that you can hold the pan with one hand while whisking with the other; you’ll need to move the pan to regulate the temperature. If you have an electric burner, use a double-boiler instead: fill a large saucepan with water and place the saucepan with the mixture inside it.
In a saucepan, separate 3 egg yolks, saving the egg whites for some other dish. Add ¼ cup (60g) white wine and whisk to combine.
Once you’re ready to start cooking, place the pan over the flame or in the water bowl bath and whisk continuously until the egg yolks have set and you have a frothy foam, about two to three times the volume of the original. This can take 5 to 10 minutes; have patience, it’s better to go too slow than too quick.
Add 2 to 3 tablespoons (20–30g) freshly grated Parmesan cheese and whisk until thoroughly combined. Add salt and pepper to taste, and serve on top of an entrée such as fish with asparagus.
Note
White wine is quite acidic, with pH levels around 3.4 (Chardonnay) to 2.9 (Riesling). Since acids help prevent egg yolks from coagulating under heat, the wine actually helps protect against coagulation. (Pour yourself a glass; that’ll help, too.)
Zabaglione (Sabayon)
This dish is easy, but it does benefit from a few practice runs. Luckily, the ingredients are cheap!
Zabaglione is the dessert equivalent of white wine and cheese sauce, made by whisking wine, sugar, and egg yolks over low heat; it’s essentially a foamy custard, but without the milk. And, like the white wine and cheese sauce, this is a great recipe to have tucked away in the back of your head.
Measure out ¼ cup (60g) Marsala wine and set aside.
Note
Marsala—a white wine fortified with extra alcohol—is traditionally used in zabaglione, but you can use other alcohols, such as Grand Marnier, Prosecco, or port.
In a saucepan, separate out the yolks from 3 eggs, saving the whites for something else (meringues!). Add ¼ cup (50g) sugar to the yolks and whisk to combine.
Place pan over heat, following the directions for the white wine and cheese sauce. Pour in a tablespoon of the Marsala and whisk. Continue adding the Marsala a tablespoon or so at a time, whisking for a minute between each addition. You’re looking for the egg yolks to froth up and foam; the heat will eventually set the egg yolks to make a stable foam. If you notice that the egg yolks are scrambling, quickly pour in more of the Marsala to cool the mixture down; it’s not ideal, but it’ll prevent you from having an entire dish of sweet scrambled eggs on your hands. Once the sauce begins to show soft peaks, remove from heat and serve.
Traditionally, zabaglione is served with fruit: spoon a small portion into a bowl or glass and top with fresh berries. You can also store it in the fridge for a day or two.
Strawberry or Raspberry Soufflé
You’re probably wondering what soufflé is doing in the section on egg yolks, right? After all, it’s the egg whites that famously give soufflés their rise. I have a confession to make. I make my fruit-based dessert soufflés by making zabaglione. (I am so never going to win a James Beard award—the Oscar of the culinary world.)
Preheat your oven to 375°F / 190°C. Prepare a 1 quart / 1 liter soufflé bowl—which will hold enough soufflé for two to three people—by buttering the inside and then coating it with sugar (toss in a few spoonfuls, then rotate the dish back and forth to coat the side walls).
Prepare the fruit:
Fresh strawberries, raspberries, and white peaches work exceptionally well; wet fruits such as pears can work, but the water may separate while cooking, so start with berries. Rinse and dry the fruit. If using strawberries, hull them; if using peaches or other stone fruits, quarter them and remove the pit. Reserve about ½ cup—a small handful—of the fruit for placing on top of the cooked soufflé. Prepare a second handful of fruit, again about ½ cup, for cooking by slicing it into small pieces; cut strawberries into eighths and peaches into very thin slices. (Raspberries will fall apart on their own.)
Make zabaglione:
Start by making a zabaglione: whisk the 3 egg yolks with ¼ cup (50g) sugar over low heat and add ¼ cup (50g) of kirsch—cherry-flavored brandy—instead of Marsala. (Save the egg whites for whisking.) After adding the kirsch, add the fruit that’s been sliced into small pieces and stir, thoroughly mashing in the fruit. You don’t need to actually cook the egg yolks until they set; you’re just looking to stir and whisk them until you have a frothy, warm, soft foam. Set aside while preparing the egg whites.
Whisk egg whites, fold, and bake.
Whisk the egg whites to soft peak stage, adding a pinch of salt for taste. Fold the egg whites into the fruit base and transfer the mixture to the soufflé bowl. Bake in an oven until the soufflé has risen and the top is browned, about 15 to 20 minutes. Remove and place the soufflé dish on a wooden cutting board. Dust with powdered sugar, place the reserved fruit on top (slice strawberries or peaches into thin slivers), and serve at once. If you’re in informal company, it’s easiest to just set the soufflé in the center of the table and hand everyone a fork to dig in.
You can use this same technique with the white wine and cheese sauce from the previous page to make a savory soufflé.
Whipped Cream
Unlike eggs, in which proteins provide the structure for foam, cream relies on fats to provide the structure for a foam when whipped. During whisking, fat globules in the cream lose their outer membranes, exposing hydrophobic portions of the molecules. These exposed parts of the fat globules either bind with other fat globules or align themselves to orient the stripped region with an air bubble, forming a stable foam once enough of them have been aggregated together.
When working with whipped cream, keep in mind that the fats provide the structure. If the cream gets too warm, the fats will melt. This is why whipped cream can’t be used to provide lift in most baked goods: the cream will melt before the starches and gluten in the flour can trap the air. Be sure to chill your bowl and the cream before whisking.
Note
Whipping high-quality cream increases its volume by about 80%, while whipped egg whites can expand by over 600%!
Percentage of fat in dairy products. If the cream doesn’t have enough fat, t
here won’t be enough fat globules to create a stable foam.
Michael Chu’s Tiramisu
PHOTO USED BY PERMISSION OF MICHAEL CHU
Tell me a little bit about your background and how you started your blog, Cooking for Engineers (at http://www.cookingforengineers.com).
I am an engineer in my professional life, but I developed recipes on my own. "Developing" sounds grander than it really is. I would try out recipes and then the ones that I really liked I would keep and then tweak so that I would like them more. Friends would come over to watch TV; at the time we called them "Family Guy Nights" because we would watch the television show Family Guy. I would be cooking and writing down my recipes when I found something I liked. I started using Blogger, and at some point I decided I would post a recipe. I took pictures of me making salsa and then I posted that recipe. My friends liked it and so I just thought, "Oh, well, maybe this is a good way to share my recipes." A lot of people started to come and look at the recipes, and it just kind of blew up from there.
One thing I notice about your posts is the number of variations you go through. Do you think people have a fear of trying variations when they go into the kitchen?
I think a lot of times people don’t like wasting food. There is a whole culture where wasting food is something that you don’t do. I totally agree with that, but when you’re trying to learn how to do something it’s inevitable that you will make mistakes. There will be some waste; that’s something people shouldn’t shy away from. When you’re trying a new fancy dish for the first time and you’ve never used the ingredients, you might use too much.
