Cold Comfort.(on making dessert)

Byline: editor: Valerie Steiker

Armed with liquid nitrogen, Jeffrey Steingarten tests the limits of the modern dessert.

It looked like an atom bomb--a scary, squat steel cylinder in battleship gray, three feet high and nearly as wide, too vast for one man to move. Out of its curved top sprouted a cluster of levers, dials, a black knob, and a long metal pipe with a rusted metal cylinder at its end. My assistant, Marisa, could no longer keep her fear in check and begged to be relieved of her duty. Sky King, the golden retriever with whom we share our apartment, sought refuge under my desk; then, after a week or so, he walked right up to the atom bomb and examined every square inch of it with his nose. Marisa did not.

In reality, there was no atom bomb sitting in the corner in our kitchen. It was a rented dewar, a double- or triple-walled container (named for its inventor, the Scottish chemist and physicist Sir James Dewar)--a mega--thermos bottle for holding very cold liquefied gases. My dewar was filled with liquid nitrogen, which the books say measures 321 degrees below zero! Sure, it's warmer than the average temperature of the universe, but otherwise it's really, really cold. Liquid nitrogen is indispensable to hypermodern pastry chefs, as are hydrocolloids, dehydrators, centrifugal juicers, siphons, and immersion circulators. These are all much simpler than they sound, especially hydrocolloids, which mystified me until somebody explained that they are essentially gums--like gum arabic, xanthan gum, agar-agar--used either to thicken liquids or turn them into jelly. It used to be that whenever I found one of these gums listed on a jar or box or pint of ice cream, I'd slam the thing back onto the supermarket shelf. But no more.

I lack all ambition to become a modern pastry chef. But for a month or two, I wanted to play with the big boys, or at least play with the big boys' toys. Last December, I dined twice at Alinea in Chicago, presided over by Grant Achatz, one of America's great chefs; Alinea is one of a handful of restaurants dedicated to a kind of cooking for which a fitting name has not yet been found. (Candidates include "hypermodern cooking," "science food," "molecular gastronomy," "high-tech cooking," "avant-garde," and "space food." I'll just call it "modern." Or maybe "contemporary," which is a moving target always pointing to the present day.)

I had two dinners at Alinea, and of the five or six desserts we were served, at least one was a certifiable masterpiece. They called it "persimmon cake with carrot, red curry, and spice aroma strip"--an ancient holiday treat deconstructed and then brought back together into an intense cluster of red-orange, green, gold, and dark wine-red. The cake batter itself hadn't been baked; Grant had cooked it sous vide for six hours--in a sealed plastic bag submerged in a water bath kept at exactly 180 degrees F.; if the cake had been baked in an oven, it would have taken on the sweet, dry, toasty flavor of oven-browning, a taste we usually consider delicious but which would detract from the purity of this cake's flavor. There were also crumbs of carrot-juice foam that had been dried in a dehydrator; the carrot juice had been mixed earlier with a gum called methyl cellulose, which guaranteed the foam's crispiness. There was also caramelized ice cream, pistachio shortbread, pistachio brittle, and a little date pudding topped with candied Iranian pistachios.

Crowning these was a magical, nearly transparent golden sphere that burst in your mouth with a flood of liquid ginger--this was ginger tea mixed with a pinch of calcium lactate powder, then frozen into a ball in liquid nitrogen and dropped into a bath of more ginger tea mixed with a bit of sodium alginate, a substance that when it touches the calcium lactate forms a delicate skin around the frozen ball. When the ginger tea thaws, the skin still holds it in the shape of a globe: ginger tea encapsulated by a skin of itself.