Baked Alaska Day

What the day is

Baked Alaska Day is observed on February 1. The dish is ice cream on a cake base, covered in meringue and put in a hot oven, and it comes out frozen inside.

Origin and background

The trick is insulation rather than speed. Beaten egg white is mostly air held in a protein foam, and trapped air conducts heat very poorly. A thick meringue layer is effectively a blanket, so the oven browns the surface long before enough heat reaches the interior to melt anything. The same principle keeps a duvet warm and a foam cup cool.

Two details make it reliable. The meringue must completely seal the ice cream against the base with no gaps, since any opening is a channel for heat. And the oven runs hot and fast, a few minutes at high temperature, browning the outside before the insulation is overwhelmed. Low and slow is the way to fail.

The physics was understood before the dessert. Benjamin Thompson, an American-born physicist who worked on heat and took the title Count Rumford, is credited with demonstrating the effect with a version of this dish around 1800, which is why it is sometimes called omelette à la Norvégienne. The American name is generally attributed to Delmonico's in New York, marking the 1867 purchase of Alaska.

The flambéed version adds a second piece of physics: warmed spirit poured over and lit burns at the surface, and the alcohol is consumed before the heat has time to travel inward.

Italian or Swiss meringue, where the whites are stabilized with hot sugar syrup, holds up far better than a raw-white meringue and is also safer to eat.

How to take part

• Freeze the assembled ice cream and cake hard before the meringue goes on.
• Seal the meringue right down to the plate, leaving no gaps at the base.
• Use a very hot oven and a short bake, or a blowtorch.
• Choose Italian or Swiss meringue for stability and food safety.
• Serve it immediately. The insulation is good, not infinite.