Ice cream's secret ingredient

There are three kinds of ice cream: cheap ice cream, good ice cream, and great ice creams. All of us would rather eat great ice cream. There is only one problem - great ice cream costs more. Why?

To find out, let's see how ice creams are made.

Ice cream is technically a frozen custard - a cooked mixture of milk or cream, eggs (sometimes), sugar, and flavorings - and plenty of whipped-in air. Without air, ice cream would be like a mushy block of ice. It wouldn't be quite as hard as ice, but hard enough that you would need a chisel to eat it. Air makes ice cream soft enough that you can scoop it and lick it off a cone.

What makes ice cream smooth, creamy, and silky? Butterfat. That's the fat that's in milk and cream. If the ice cream maker uses milk, the butterfat content is lower. Light cream or half-and-half makes the butterfat content higher. Ice cream made with heavy cream is oozing with creaminess.

Next come flavorings (natural or artificial) and finally what the ice cream people call "inclusions." Inclusions are good stuff that's included - like mini-marshmallows, peanuts, M&Ms, and nearly anything from the bake shop - chocolate truffles, pieces of brownies, cakes, or cheesecake, even chunks of doughnut, cookies, biscotti (twice-baked Italian cookies), and chocolate-covered nuts. The list is endless.

Inexpensive ice cream tends to have inexpensive ingredients. That means low butterfat content (milk instead of cream), artificial flavorings rather than natural ones, and inclusions that are low-cost or nonexistent.

High-priced premium and superpremium ice cream is loaded with butterfat, natural flavorings, and high-quality inclusions.

And what about air?

By law, a gallon of ice cream may contain up to a gallon of air. At that rate, when you eat a bowl of ice cream, half of what you eat is air. (Talk about inexpensive ingredients!) Superpremium ice cream is about 25 percent air, or less - just enough air to make the ice cream fluffy but still very, very rich tasting and dense.

Regular ice cream contains 10 to 12 percent butterfat. Superpremium ice cream is 15 to 18 percent - about the same as slurping a bowl of half-and-half. Which would you rather eat? A bowl of half-air, half-ice cream? Or a smaller serving of a rich, creamy dessert? I know which one I'd prefer - quality, not quantity.

The ice cream "family" includes many siblings, cousins, and second cousins. A lean cousin is ice milk, in which milk replaces cream. Sherbet, also called sorbet (sor-BAY), contains even less milk or none at all. Butterfat content for sherbet might be a mere one percent or less. Frozen yogurt is also low in butterfat, about 2 percent.

Gelato (juh-LAH-toe) is an Italian relation of ice cream. It's especially dense (less air) and creamy. Spumoni is an Italian sherbet blended with a large amount of Italian meringue. (Italian meringue is cooked beaten egg whites sweetened with hot sugar syrup.) It is wonderful. Granita (gruh-NEE-tuh) is a light, frozen fruit-juice dessert originally from Spain. It has a grainy texture. It's very refreshing on a hot day.

Flavored sweetened ices were popular at Roman feasts 2,000 years ago, when they were made with snow brought by runners from the mountains. But ice cream as we know it was perfected by Italians in the 1600s. Soon after that, the English and French introduced it with great success. They had no freezers except salted ice (the salt causes a chemical reaction that makes the ice colder). They made ice cream the way we make home-made ice cream today.

The first recipe for true ice cream appeared in an English cookbook by Mrs. Mary Eales in 1718. Without today's ice cream technology, her recipe must have resulted in a coarsely crystalline concoction.

In North America, ice cream became tremendously popular during World War II. United States troops had ice cream delivered to them for dessert whenever possible, and returning soldiers continued ending their meals this way. Today even Asian countries import American ice cream, even though dairy foods are not popular in Asia.

We all scream for ice cream, it seems. But some scream louder than others - and for different flavors.

New Zealanders wear the world's ice-cream crown. Kiwis consume 57 pints per person each year, compared with 40 pints in the United States. Vanilla is tops in both countries, but "hokey pokey" (vanilla with toffee bits) beats chocolate for No. 2 in New Zealand.

Iranians, on the other hand, enjoy rose-flavored "Bastani Akbar-Mashti" ice cream, named for a Persian ice cream impresario. In Nigeria, vanilla ice cream is topped with bananas, fresh mangos, and orange juice. Green tea ice cream is big in Japan, while Indonesians enjoy popsicles flavored with durian fruit. (Durians may taste good, but they smell so bad they are banned from any public place in Asia.)

Sweet corn ice cream rules in the Philippines. The Chinese serve shaved ice with milk and strawberries ... or red beans. Talk about exotic inclusions.

This classic American recipe was reportedly invented by an American-born physicist, Benjamin Thompson Rumford, in 1804. (He was handy in the kitchen, for he also invented a double boiler, a coffeemaker, and the kitchen range.) Rumford later wrote that his recipe was a byproduct of his studying the insulating properties of beaten egg whites. The many tiny bubbles in the whipped egg whites conduct heat poorly. The meringue, as it's called, keeps the ice cream from melting as the egg whites cook. Rumford called it an 'omelette surprise.' A similar recipe with 'Baked Alaska' in the title appeared in the 1850s. Delmonico's restaurant in New York City popularized the dessert when its pastry chef created a version (he called it 'Alaska, Florida') to celebrate the United States' purchase of Alaska in 1867.

You can duplicate Rumford's delicious experiment. This recipe takes very little effort and yields an impressive result. It requires some speed and organization on your part. You will also need the enthusiastic cooperation and supervision of an adult, because a hot oven is involved.

You will need:

• a plain (unfrosted) sponge or angel food cake, available at most bakeries. (Our tester bought a pan of brownies instead!)

• one half-gallon of ice cream in a brick-shaped carton. (A half-gallon makes two recipes. Hint: A nonvanilla flavor makes it easier to see if you missed a spot with the meringue.)

• 4 egg whites at room temperature (We recommend using dried egg whites.)

• 1/4 teaspoon cream of tartar

• 1/2 cup granulated sugar

1. Find a thick wooden board that's at least four inches longer and four inches wider than the ice-cream carton's width and length. This will be your baking platter. Cover it with aluminum foil.

2. Put oven rack in the center of your oven. Preheat oven to 475 degrees F.

3. Unwrap the carton of ice cream. Slice the ice cream in half so that it makes two large, thin rectangles (as in illustration below). Put the ice cream slices back in the freezer.

4. Trim the cake (if necessary) so that it's not too high - it should be about three fingers tall. The ice-cream rectangle will sit atop the cake, so make sure that the cake is an inch or so longer and wider than the block of ice cream that will sit on top.

5. Center the cake on the foil-covered board. Now center one of the ice-cream blocks on top of the cake. Return board, cake, and ice cream to freezer.

6. Put egg whites into a large bowl of an electric mixer (or reconstitute dried egg whites according to directions). Sprinkle cream of tartar on top. Using beater attachment, beat until the whites form soft peaks when you stop the mixer and lift out the beaters. (The tips of 'soft peaks' flop over.) Gradually (and carefully) add sugar to the egg whites as the mixer is running. Beat another minute or so to form firm peaks. (When you stop the mixer and lift the beaters out, firm peaks don't flop over.) Don't overbeat!

7. Remove cake and ice cream from freezer. Using a rubber spatula, thickly cover sides and top with the egg-white foam, leaving no part of cake or ice cream exposed. This is the insulation that will keep the ice cream from melting. The foam shouldn't be smooth and even - make it uneven and raggedy. The ragged peaks will brown first, letting you know it's done.

8. Bake in center of your preheated oven for five minutes, then check. Remove from oven when light brown speckles appear all over the meringue.

9. Admire your Baked Alaska. Cut into slices with a serrated knife and serve at once. Cover leftover with plastic wrap and return it to freezer.

Serves eight.