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The Culinary Art of Coffee | David Schomer

November 22, 2014

David Schomer tells a tantalizing story of how to tease delicate fragrances and complex flavors from coffee into your cup.


Full talk transcript

My family arrived in Seattle's Wallingford district in 1958 — I was only 2 years old.  One of my most fond memories: When I was about 4, I started to walk every week with my mother to the Food Giant on 45th street, and we would go up the coffee aisle and stop in front of a big red machine and they would grind the beans for you in the store back then.  She would take a little brown tin tie bag and put it into the shoot and push a button,  and there would be a vroom sound and the fragrance of the grinding coffee would billow over the aisle and it would envelop me. In my imagination, it promised an exotic adulthood filled with impossibly rich experiences, not the least which would be to finally try coffee. And, yeah, you know what's coming, because when I was 19 years old I was in the U.S. Air Force and I finally tried coffee.  And in the lab at 11:00 at night, whatever came out of this aluminum cylinder with the little black handle did not quite match my imagined flavor. 

And for the next ten years I studied classical flute, and I worked at Boeing's Class A  Standards Lab as a meteorologist — this is a precision measurement specialist.  And by age 31, I really had a desire to do something beautiful for a living, so Geneva  Sullivan and I started a cart on Broadway in 1988 and she is my trusted partner who saves me from any real work.  We started this cart, and I became intrigued with cafe espresso. I said, here is a beautiful culinary art, perhaps in its infancy, that relies on a rigorous scientific technique.  And it's an art that people will buy because it has drugs in it.  I said this is right down my alley!  And now, 58 years later I have to realize I’ve dedicated my entire professional career to try to seduce the fragrance of coffee into a cup to enjoy as a flavor.  And this is that story.

 I’ve dedicated my entire professional career to trying to seduce the fragrance of coffee into a cup to enjoy as a flavor.

Why is it that ground coffee smells so good and usually tastes bitter and stringent in the cup? A complete answer is very complex. But of course, the most important factor is the coffee itself. When you roast the seeds of a coffea arabica tree, it is also called caramelization, because in the roaster it develops caramelized sugar, heat, carbon dioxide, and hundreds of very fragile aromatic compounds. These delicate fragrances are so fragile that they defy scientific classification because the act of measuring them destroys them.

When I taste coffee, I think in terms of two general categories: That's the caramelized sugar, of course, but of varietal tones, like wine. Coffee will pick up a recognizable flavor group, if you will, from the region it's grown in. So, an Ethiopian Harrar will feature a dark chocolate umami with a blueberry aftertaste in the best of it, and a very heavy body. A Brazil is recognizable as a Brazil because it has a light body and a hoppy, spicy taste. Either way, these delicate aromatics trapped in the coffee beans can survive up to ten days if you store them in a cool dark place in the original bag you got it in. So, the first answer to why coffee usually tastes rancid in the cup is that the customers receive stale beans, or worse, pre-ground coffee. When you grind coffee in a favorable environment — cool and moist like Seattle — it's on peak for maybe 20 seconds. And what about brewing it? It was either the French or the Italians, over 125 years ago, who had the intuition that if we pressurized brewing water and shortened the percolation cycle, maybe we can get more of the fragrance into the cup.

He said, "David, the espresso is an equation with a thousand variables and only one perfect solution." When I returned from that trip, I developed my approach. I was going to isolate and perfect each factor that affected this espresso coffee.

This is correct. Longer saturation methods such as French press or drip cone, however lovingly applied, can only offer a crude approximation of that fragrance, and maybe some notes on the roasting in the final cup. So it is true that it's technically possible to preserve the fragrance using the espresso method, but to do so is extraordinarily complex. The way the late Dr. Ernesto Illy explained this to me in Trieste, I visited him in 1989, my first visit, and he said, "David, the espresso is an equation with a thousand variables and only one perfect solution." When I returned from that trip I developed my approach. I was going to isolate and perfect each factor that affected this espresso coffee.

I do come from an engineering family, and remember, my specialty was precision measurement. As I worked it occurred to me, these machines, they're being sold all over the world. And outside of Italy, there was absolutely no standard practice. I published my factors approach in 1995 in a book called Espresso Coffee Professional Techniques. But, when I worked with the factors, to be honest, I was not quoting the fragrance in a cup, and if anything, I am brutally honest with my tasting of this. I began to suspect that during the brewing, the temperature of the water was changing.

It was Sergio Michael back in Trieste who told me many things, but one thing he said: “David, each brewing water temperature of course gives you a different coffee.” So I got my metrology hat on again, and using this rig, I began to document the performance of all the machines. In this is where the bead probe dances right on top of the coffee — there's no hiding. So I began to document the performance of all the machines in the West Coast. The best of them, La Marzocco Linea, would climb six degrees during the 25 seconds it took make the shot. The worst of them would plunge up to twenty degrees. My theory at the time was that you had to hold the brewing temperature to 203 degrees with less than half a degree of change, and only then would the fragrance make it into the cup. I was furious. A $39 Mister Coffee has better control than these $10,000 machines that are all over the place, and I wrote this and I wrote this and I wrote this some more, in a series of articles entitled “Engineered Mediocrity.”

So what happened was, I was able to narrow the range in temperature to two degrees working with La Marzocco engineer John Blackwell in ’95 — the machine I was using was the La Marzocco. Immediately, the coffee was darker and richer, but still a mish-mash of flavors. On February 28, 2001, working with Roger Whitman of La Marzocco, John Bicht, an independent genius who runs Versalab, and myself, we took an Omega P.I.D. controller — think of it like a computerized thermostat — and we stabilized the brewing water temperature to 203, to a half a degree of error for the first time in human history. And the actual prototype is here, and the little controller is hanging in that pastry box on the sign on your left.

So it was true. We had created this culinary art. And now, in 2014, every machine manufacturer has a P.I.D.-controlled machine and they fall all over themselves to claim the best temperature stability. So the espresso as a culinary art actually started that day, February 28 in 2001. And what the new machines have revealed is the extraordinary sensitivity of this coffee to flow rate. Here's the coffee flowing out of a machine before we modified temperature all the way perfect. The white streaks literally are dead flavor areas — it's a pretty decent pour. Here's what it looks like in 2013 on the absolute tricked-out equipment from Nuova Simonnelli, and color is flavor and the viscosity is evident.

In this window of two seconds, there are 30 unique different coffees, there are different varietal flavors.

So what the new machines have revealed is the impossible sensitivity of the coffee itself to exactly how fast it flows into the cup. I don't want to bore you to death here, but we have a two-second window when we worked that bar between 24 and 26 if the shot is too fast, it is destroyed, it is sour and astringent. If this shot is too slow, 28 seconds, the flavors incinerate and it’s hollow. In this window of two seconds, there are 30 unique different coffees, there are different varietal flavors. The Ethiopians compete for your attention, or the Indian Malabar, impossibly beautiful, and of course any culinary art requires a presentation.

So in 1989 we began developing latte art patterns. These flowing patterns are merely silky foams doing what they want to do. This one is called shadow heart. This one, wreathe and heart, and finally caffe latte rosetta. So there's more work to do. I would really like to get a better grinder, I would really like to tune the mineral content of the water, but I’d have to say, yes, my teasing muse coffee has kept her fragrant promise she made to me 54 years ago in the Food Giant.

Thank you.


Speaker Bio

David Schomer is the founder of Seattle’s Espresso Vivace, a Seattle-area coffee shop and roaster praised for its high quality of coffee and roasting practices. Schomer is known within the coffee industry for his innovations, such as how he customizes his grinders and espresso machines to achieve a more constant water temperature, which ultimately leads to a better cup of coffee. Barista and coffee-bar owners have traveled from as far away as Australia and the UAE to learn from him. Read more