atom scientist | chemical release | J. Robert Oppenheimer

"It's almost impossible to make a perfect cup of espresso," he tells me, taking out an old-fashioned popcorn popper and roasting the green coffee beans himself. Arnold uses a Rancilio grinder, a precision instrument with dozens of settings. "The main thing is not to use the blade or propeller-style grinders. You get an uneven blend, and there's lots of dust - it's a real nightmare," he says, shuddering. "How fine a grind you want to use is a variable - it depends on the humidity in the room, the atmospheric pressure, your temperature setting, and a lot of other things." Even the amount of ground roasted coffee isn't constant. Arnold hates the use of dosers, the fixed measured servings used in restaurants. Everything that takes away control of the process bothers him. The tamping, the packing, using just the right water - Arnold is as careful about every step as an atom scientist working with live plutonium. The one fixed quantity in the espresso process, he says, is time: It should take 25 seconds to make a perfect shot. "Too long, and it gets bitter. Too short, and it's thin. It's a very precise balance, and I really try to stick to it," he explains, loosening his tie.

Several other adjustments are made, including setting the steam pressure to 1.5 bars - equivalent, I'm told, to the atmospheric pressure in the room plus half. Arnold busies himself with measuring the weight of the coffee, all the while discoursing on the intricacies of preinfusion, the chemical release of oils under heat, and the niceties of acidity and wineyness in African versus South American coffees. Finally, the espresso is made. Arnold admires it, showing me the telltale "tiger stripe" that marks it as perfectly­ made. Am I ready to try it? I am. I feel a little like J. Robert Oppenheimer, waiting to see if the atomic bomb will detonate. Will this be the best espresso I have ever tasted? Will it transcend, in balance, flavor, and body, every cup of coffee haphazardly made by college dropouts that I have ever gulped down before? Will it live up to the epic efforts of the geek gourmet?