- Tame overall sweetness
- Limit amount of sweet meringue
- Eliminate ice crystals in ice cream
Baked Alaska is the unicorn of the dessert world; everyone has heard of it, but few have seen one in real life. Maybe that’s because its three components—a circle of cake topped with a dome of ice cream and covered in meringue—make it sound too fussy to cobble together at home. Or maybe Baked Alaska seems intimidating since it appears to defy the law of physics: Baking this dessert in a very hot oven browns and crisps the billowy meringue exterior while leaving the ice cream core frozen and firm. Some restaurants further heighten the drama by lowering the lights, dousing the creation with liqueur, and setting it ablaze at the table.
That said, the dessert is still basically a dressed-up ice cream cake, and it’s no more difficult to make than any other version. My own reasons for not throwing one together more often have always been that Baked Alaska is very sweet, and the traditional bombe shape—while visually impressive when whole—is difficult to slice and serve neatly. Even if you do manage to cut neat slices, the meringue and ice cream invariably part company when you move the slices from the platter to dessert plates. My goal was to reengineer Baked Alaska so it would be as enjoyable to eat as it is impressive to behold.
My first move was to pick a style of meringue: French, Italian, or Swiss. The drawbacks of the French kind are that the egg whites don’t fully cook and the result is relatively coarse and foamy. I prefer the other styles because the eggs are fully cooked and the sugar completely dissolved. The results are not only food-safe but also creamier, denser, and more stable.
Ultimately, I chose the Swiss version, which is a bit easier to make. The basic method is to gently whisk egg whites and sugar in a bowl over simmering water until the mixture reaches 160 degrees and then whip the mixture in a stand mixer until stiff peaks form.
As for the cake, Baked Alaska can be made with anything from a lean and airy genoise to a rich and tender pound cake to a brownie. I thought that the brownie sounded like a nice flavor and visual con-trast to the meringue. Sticking with the traditional bombe shape for now, I baked a basic brownie in a 8-inch round pan and packed softened vanilla ice cream into a plastic wrap–lined bowl with the same diameter. To form the ice cream cake, I pressed the cooled brownie round onto the ice cream and popped the whole thing in the freezer. Once it was firm, I unmolded the cake and covered the surface with a thick layer of meringue (which was tricky, because it tended to slip down the surface of the ice cream). Finally, I baked the Alaska in a 500-degree oven for just a few minutes until the exterior was brown and crisp.
I was right—everyone liked the chocolate flavor and visual contrast of the brownie, but in combination with the ice cream and that thick coat of meringue, the whole package was much too sweet. Plus, the ice cream turned icy when I refroze it before baking. Decreasing the amount of meringue reduced some of that sweetness but doing so came at a cost. When I baked off another Alaska covered with about half as much meringue, the ice cream core turned to soft-serve.
Lesson learned: That voluminous meringue coat isn’t there just for aesthetics. Its primary function is insulation. The meringue protects the ice cream at the center from melting in the heat of the oven.
Here’s how it works: When egg whites are beaten, they form a foam—a liquid (egg whites are primarily water) that traps millions of tiny air bubbles and holds them together in a solid shape. Egg foams make great insulators because the air bubbles contain relatively few molecules and thus conduct heat energy poorly. The more meringue I used, the better the insulation would be.
If I couldn’t reduce the amount of meringue, maybe I could at least make it less sweet by replacing ¼ of the sugar with corn syrup, which is less sweet. But recalibrating the meringue only marginally reduced the dessert’s overall sweetness. To really make a difference, I’d need to reduce the amount of meringue, too, which would bring me back to my compromised insulation problem. Or so I thought.
Accounts vary, but many sources attribute the invention of Baked Alaska to Count von Rumford, an 18th-century physicist and pioneer of thermodynamics who is also credited with the invention of the double boiler, the modern kitchen range, and—most fittingly—thermal underwear. A popular version of the story is that Rumford’s original name for the dessert, omelette surprise, changed decades later when chef Charles Ranhofer of Delmonico’s in New York City dubbed it Baked Alaska in celebration of the United States’ acquisition of the territory in 1867.
Up until that point, I’d been relying almost exclusively on the meringue for insulation. But cakes are also foams with the ability to insulate, so maybe I could make better use of that component. I’d actually seen a couple of Baked Alaska recipes in which the ice cream was completely encased in cake and had dismissed them as overkill. Now I recognized this as a potentially genius move that would allow me to cut way back on the meringue while keeping the ice cream well insulated.
But in order to do so, I had to make some changes—starting with the type of cake. The brownie was not only too sweet but also too inflexible to encase the ice cream, so I switched to a chiffon cake. Because this cake is made with whipped egg whites, it’s not only spongier and more flexible than a brownie but also contains much more air, making it a better insulator. (Its plain flavor wasn’t an incentive, but I’d revisit that later).
Using the more-resilient chiffon cake also allowed me to change the way I engineered my Baked Alaska. Rather than line a bowl with cake pieces and soft ice cream, which always resulted in icy ice cream and messy slicing, I abandoned the bombe shape and instead turned the ice cream into a cylinder and wrapped cake around it.
How is it that ice cream wrapped in cake and covered in a layer of meringue can remain frozen solid for a good 5 minutes in a 500-degree oven? Meringue (and, to a lesser extent, cake) is full of tiny air bubbles that provide terrific insulation, since they conduct heat poorly. Heat causes molecules to vibrate and bump into one another, transferring energy. Since air bubbles contain fewer molecules, heat transfer is slow.
The final results were even more encouraging: Not only were there no drips of melted ice cream, but the slices I cut were tidy and intact and the cross-section view was striking: a half circle of ice cream surrounded by cake and just enough meringue.
All I had left to revisit was the flavor. Since the chocolate brownie had been a good match for the meringue, I made the chiffon cake chocolate by substituting cocoa for some of the cake flour.
To make the flavors even more complex, I tried a series of tart sorbets in place of the plain old vanilla ice cream; they had good flavor but were too lean in this dessert. Instead, I used a premium coffee ice cream that was rich, creamy, and had just the right hint of bitterness—a great match for the other components.
My version of Baked Alaska wasn’t just an edible science project about insulation; it was a showpiece dessert that tasted every bit as good as it looked.
Conventional recipes for Baked Alaska often look impressive but tend to be achingly sweet and hard to slice neatly. We reengineered all three components, including wrapping the entire ice cream core in cake, which allowed us to use less meringue, for a dessert that looks and tastes great.
All cakes insulated the ice cream from heat to varying degrees; genoise and chiffon cakes were the most effective because they contain more insulating air bubbles that keep the ice cream colder. Both chiffon and genoise were also resilient enough to be wrapped around the ice cream, but we chose chiffon for its slightly richer flavor and more tender texture.
We wanted a creamy meringue that was easy to make. After experimenting with the three classic types, we chose a Swiss meringue and made it less cloying by replacing some of the sugar with corn syrup.
Our goal was a complex-tasting, not-too-sweet frozen core.
Tame overall sweetness
Swap corn syrup (which is a third as sweet as sugar) for a portion of the sugar for a less-sweet meringue, and use a not-very-sweet flavor of ice cream (coffee).
Limit amount of sweet meringue
Instead of using the cake merely as a base, completely surround the ice cream with cake because it insulates in the same way that meringue does. That way we can use far less meringue.
Eliminate ice crystals in ice cream
Softening and then refreezing the ice cream created ice crystals. Instead we press two 1-pint containers of ice cream together to form a cylinder and use that as our base.