Espresso Blends? – Brewing with Single Origin Coffees

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Oct 10, 2007

Cup of Excellence and estate-identified coffees are receiving plenty of attention these days–not just around their provenance and terroir, but also with regard to specific preparation techniques and brewing parameters for getting the most out of them. Usually, these super-premium typicas and bourbons are filter brewed, French pressed, or Cloverized. However, I am also hearing more about original experimentation around using these highly desirable coffees as single origin espressos.

I have been warned that there are some problems with this idea, since espresso coffees are purpose blended for higher temperature extractions under greater pressure than pure brewing. French press and Clover devices do apply a small amount of pressure beyond that created by natural gravity, but these remain essentially saturation-style brewing machines. At this point in specialty coffee’s evolution, French press (and to a lesser extent Clover) remain the standards for optimizing the flavor and body that premier single origin coffees offer.

Still, the idea that some of the finer aspects of brewed coffee flavor and characteristics can be realized from an espresso extraction is compelling (even if such thinking is unconventional and possibly wrong-minded). Recently, Jason Prefontaine brought some single origin Organic Guatemalan, Asobagri Coop to try as an espresso. He had been experimenting with it as a single origin espresso in his Calgary lab and was getting some fair results. This coffee is a combination of two varieties: typica and caturra.

At our Seattle studio, we tried extracting this coffee as espresso using our standard setting of 202 F and 8.5 bars of pressure. We started at this temperature and pressure partly because it gave us a familiar baseline–a safe espresso setting for the pressure, humidity, and altitude around these parts. Also, Calgary is positioned at almost 3,500 ft above sea level, and experience has shown that perfect brewing parameters for these elevations usually don’t translate seamlessly to sea level situations.

We began by pulling an 8 gram single in 20 seconds using a tall profile single insert. The result was ghastly. The coffee was bitter, acidic and unpleasantly sharp. These extreme profiles blocked out any nuances or pleasant notes we were picking up when the coffee was brewed as a French press—basically, the espresso extraction just destroyed everything good we were hoping for. This disappointing outcome is probably what we should have expected playing around like this.

On our second pass, we bumped up brew temperature to a very hot 207 F. We also substituted our single basket with a ridgeless double basket (16 grams) and extracted over a slightly longer 22 second period. The results were smoother than our first test. We began to pick out a very faint citrus note. But the brew was still dominated by the extremely unpleasant sharpness etc that we had experienced with our initial single shot extraction, just to a lesser degree. Though this outcome was not what we were looking for it did seem we were on the right track.

Our next kick at this involved increasing our coffee quantity, maintaining the same brew temperature and pulling a slightly shorter shot (a ristretto really). To do this we used a triple basket. Again, this basket was the ridgeless variety, introduced initially by La Marzocco with the Swift EPS grinder. To accommodate this much coffee, and achieve a reasonable extraction time, we also coarsened the grind ever so slightly. We use an Anfim grinder, so its hard to quantify how much coarser this grind actually was. Our goal was to achieve an extraction time of 20 seconds for a one ounce shot. Fortunately our guestimation nailed the time exactly (20 seconds). And, the result was amazing.

We first noticed something different was happening as we watched the shot develop and emerge from the naked portafilter. The coffee oozed extremely slowly and the individual streams of deep red mahogany joined at the center of the basket to form a single caramel column. It was total magic. Unfortunately I did not take a video or record the moment, but everyone has probably seen this kind of action when brewing a really great conventional espresso blend.

Furthermore, the flavor of this extraction lacked most of the bad characteristics of our previous efforts, as well. There were no sharp, bitter tones distracting our palette, only the fruity citrus tones that defined the Guatemalan in its brewed form. When we used this coffee to make macchiatos, the milk smoothed it further and created a distinctive drink.

Hopefully other people are trying this stuff at home as well. I don’t know if there is a future in this kind of espresso brewing, but I am looking for more coffees to take down this path and find out.