After over a decade at Babbo, I've made a helluva lot of zabaione. Enough to fill Fiat Cinquecento, I'd say, and I never grow tired of it. Zabaione, or its alternate spelling of Zabaglione, is a marvel of a dessert—with three basic ingredients and a bit of practice at whisking over a water bath, you are rewarded with a warm, boozy, egg-y cloud of deliciousness, the down comforter of the dolci universe.
It is also the ideal last-minute dessert fix; all you need to make a fantastic zabaione is egg yolks, wine, sugar, and some good arm muscle. The basic formula to serve four generously is 4 egg yolks, 1/4 cup wine (or a combination of wine and spirits), and 1/4 cup sugar. I like to add a tiny pinch of salt to enhance the flavor. The recipe can be doubled to serve a crowd, and modified slightly to play with the flavors. Try not to stray too far from these proportions, however; zabaione is an emulsion, and the proportion of fat to liquid plays an important role.
I like to make my zabaione with Vin Santo, because it is a wine with both sweetness and acidity. I sometimes combine the Vin Santo with rum or grappa; you can use brandy or any infused spirit to create whatever flavor you want. Marsala creates the flavor that most Americans are familiar with, but in Italy, the wine of choice is usually something local, which isn't difficult since every region produces at least one sweet wine. In Piedmont, where zabaione originated, it is often made with bubbly Moscato D'Asti, or Brachetto D'Acqui.
It is important be familiar with the flavor of whatever wine you choose. Some dessert wines are high on the sweet scale, and in that case you may start with a larger proportion of something drier, adding the sweeter wine as an accent, or adding one or two teaspoons of fresh lemon juice to balance things out.
The list of ingredients for zabaione may be short, but the devil is in the details. Start off with selecting the right bowl. At Babbo, I use a heavy copper bowl that once belonged to the Coach House, and it works just beautifully. Copper conducts the heat from the boiling water bath evenly, allowing you to control the cooking process. If you don't have a copper bowl, glass is the next best choice; its insular properties prevent the zabaione from overcooking in spots. The goal is to create heavenly, luxurious foam. Thin, stainless steel or ceramic bowls heat far too quickly and unevenly, and before you know it, you've made an omelet. Plastic is just a plain no-no.
The pot that you choose for your boiling water bath, or bagno maria should fit the bottom and about one-half the sides of your bowl, allowing it to fit snugly and comfortably without too much tilting to one side or the other. You should be able to lift the bowl (with potholders or a kitchen towel to protect your hands) off the pot without too much difficulty.
It is also important to use a round bowl, not one with a squared or angled bottom, so the whisk travels smoothly across and through it. The final consideration when matching your pot to your bowl is depth; you should be able to simmer at least 4 inches or so of water, with a good inch of space between the water and the bottom of the bowl; be careful not to allow the water to touch the bowl.
The last vital piece of equipment is a good whisk. Unless you are making dessert for an army, a medium sized, 12 to 14-inch whisk will work just fine, preferably round or balloon shaped with flexible tines. Pick one that feels good in your hand—not too heavy, not too light—and do a few test strokes in the bowl. If you can comfortably create a smooth, fluid whisking motion, you're set to go.
Simmer and Whisk
Bring the water to a simmer. In the meantime, whisk the egg yolks and sugar together to combine them, remembering the golden rule: never dump sugar on egg yolks and hesitate or walk away, even for a few seconds. The sugar will "burn" the yolks—creating hard, unpleasant clumps that won't dissolve. Whisk in the wine or combination of wine and spirits, a wee pinch of salt, and if necessary, the lemon juice. Whisk the ingredients together off heat to create a foamy texture that will give you a good head start.
Place the bowl over the simmering—not boiling—water and keep whisking. Remember to always keep the mixture moving in an up-and-over motion. The goal is to incorporate air into the zabaione as you cook those yolks. This isn't the time to change the TV channel or answer the phone (heck, I don't even like to talk when I'm making zabaione); you're pretty much stuck there until it is done.
Monitor the water by occasionally lifting the bowl up and taking peek. If it is boiling, lower the heat to a simmer, as a full boil may result in bits of cooked egg forming on the sides of the bowl. The zabaione will start to turn thick after four or five minutes of steady whisking.
There are signs to look for that will signal it is almost done: The whisk will leave tracks in the zabaione as it moves through it, and the mixture will start to come away from the side of the bowl, and it will mound easily. At this point, I start to perform my 8-second test: Lift the whisk up and let some of the zabaione fall back onto itself. Count how long it takes before the fallen shape flattens, and when that point reaches 8 seconds, you're done. Take the bowl off the heat and place it on a folded kitchen towel on the counter.
Wait, you're not done. Keep whisking. That's right, keep whisking. It is necessary bring the temperature down a bit, which will help the zabaione thicken further. I understand you might be tired at this point, but who can't use a little more arm toning? How long to whisk it off heat depends on how you wish to serve it. My favorite way is warm or at room temperature, to get the full impact of boozed-up egg. Chilling it by whisking over a bowl of ice water or beating it completely cold with an electric mixer works too, but mutes the flavor somewhat.
In a restaurant kitchen, it is common to fold chilled zabaione into whipped heavy cream. I do this myself with a heavy heart; the cream allows us hold the zabaione for the many long hours of service and shape it into a perfectly round quenelle on a plate, but we lose some impact of that wonderful, egg-y flavor. If I had my druthers, all my zabaione would be made in the dining room and served warm, tableside, as my brethren do at Del Posto.
Serve the zabaione over a slice of cake, crostata or panettone, on top of fresh fruit with a sprinkle of toasted almonds, or alone in a beautiful dessert glass with some biscotti, amaretti or savoiardi alongside. It is not often that a dessert is soothing, comforting yet elegant all at once, but zabaione fits this bill perfectly.