“Mad scientist and mixologist” Dave Arnold works on a cocktail
I watched as Dave Arnold, mad scientist and mixologist, combined an equal quantity of alcohol with water. The result was bizarre: the volume of the two liquids contracted and the temperature rose. Why? Arnold waved his hands about as the scientists in the room scribbled equations. “It’s too fricking complicated!” Arnold lectures Harvard undergraduates as a visiting chef for the heavily over-subscribed “Science and Cooking” class. This year, he also gave a public lecture. Talking a mile a minute, all hopped-up energy, dancing around a lab bench with beakers and thermometers and vacuum sucking machines and blowtorches, Arnold held the audience rapt.
Arnold stirred marshmallows with liquid nitrogen and tossed them into the audience: strange frozen icebergs that calved shards and squeaked when you bit them. The woman sitting next to me carefully wrapped hers in a twist of notepaper to take home; I didn’t have the heart to point out to her the principles of heat exchange. A volunteer was asked to plunge his hands into two beakers, one of oil, the other of water, each set at 60 degrees Celsius. In a second he snatched his hand out of the hot water, but said his other hand, submerged in the oil, was perfectly comfortable. It turns out that oil is a very bad conductor of heat—how weird is that? The science of cooking is mysterious alchemy. Scientific explanations are only just catching up with what cooks have long known through experience. It turns out, for example, that no one knows at what temperature sugar melts. (No wonder I can’t figure out how to make caramel).
Arnold has a bar in New York, Booker and Dax, named after his sons, and while half his time is spent building Heath Robinson machines for chefs to play with, the rest is spent in the pursuit of cocktails. He has been perfecting the gin and tonic for eight years. “It’s a very easy drink, but they always suck,” he explained to a group of us after the lecture. He deconstructed it: gin. That should be Tanqueray, according to Arnold. Tonic water made from citric acid, a sweetener and quinine sulphate he dismissed as fake and sweet and bad. Instead he made it with clarified lime juice, a simple syrup for the sweetener and quinine sulphate. Put this together with the gin, then chill, then carbonate the whole thing. Arnold likes a lot of bubbles. “It is a scientific fact,” he grinned, “that bubbles make the alcohol go to your head faster.”
He demonstrated infusion—not the gentle warming and wait method, but a faster more efficient version he called “pressure shift infusion by nitrous oxide.” “There are two chemical processes at work during infusion,” he explained. “The first pushes the liquid into the solid, the second returns that liquid, now flavoured, back. This is what you are doing when you are making coffee or tea.” Accordingly he put sliced turmeric and gin into a flask normally used for pushing air into cream to whip it. A canister of nitrous oxide (laughing gas) provided the pressure. The gin was forced into the tiny air pockets of the turmeric and after a mere two minutes, Arnold released the pressure with a bang. The now flavored, and bright yellow, turmeric-saturated gin was released back into the body of liquid.
Afterwards we drank the resulting cocktail, putatively named a turmeric sour. Turmeric-gin, clarified lime juice, homemade orange bitters. It was a glass of bright yellow ochre, opaque like light through a blind against an Indian sun, and the turmeric, distilled (I use this in the unscientific sense) of its dusty powderiness, provided a little heat at back of the throat, as if an elephant had trodden on a bunch of curry leaves. Then came the lime, a bright gleam of light through a jungle; gin, a colonial hat-tip, and in the receding distance, only half remembered in the moment of swallow, an unidentifiable edge of orange bitters. It was revelatory and delicious.
For his finale, Arnold fired up his new toy, a puffing gun—a pot bellied cast-iron cannon used by Chinese street vendors for puffing rice with heat and pressure, with a roaring jet of blue flame.
“Is the pressure high enough yet?” His assistant shook his head. A minute later: “Now is it high enough?” The assistant continued to shake his head—something wasn’t working. The audience leaned forward, tittering with anticipation, as a wisp of smoke uncurled from the barrel. A burning smell passed through the front rows. The presiding Harvard professor rose from his seat to try and stop the—BANG! Smoke poured into the auditorium. Arnold, abashed, oops, held his head in his hands, the fire alarm went off and the audience wildly applauded before being evacuated.
