For some reason, I think Jean-Luc would approve of pushing the envelope in espresso extraction, despite his obvious preference for “Tea, Earl Grey, hot.”
My mind has been bouncing all over the place, as I consider what more knowledgeable and experienced minds have had to say concerning the science of espresso extraction. Pressure profiling, temperature profiling, lever espresso machines, semi-auto espresso machines, ….the list could go on. Tim Wendelboe has some great first thoughts on the La Marzocco Strada. James Hoffman has shared his thoughts regarding pressure profiling here, and a follow-up piece here.
I just finished paging through a Flickr stream of photos by Mark Prince, known by many for his Coffeegeek website and forum. I would highly recommend you take the time to look at his collection of photos from the Cagliari Espresso Museum. Some very beautiful espresso machines!
As I considered the aesthetics of lever machines, this question came to mind: “Why do espresso machine manufacturers no longer make such beautiful equipment?” True, the looks of the machine have little to do with the quality of the espresso being served, but it seems we have lost some of the elegance of by-gone years. I got to witness that elegance first hand when attending Nuova Simonelli product demonstration featuring the Victoria Arduino Athena Leva, and demonstrated by the wonderful Gwilym Davies, 2009 World Barista Champion. It was a wonderful learning experience for me, and fired my enthusiasm for finding a way to incorporate a lever espresso machine into daily use in an American coffee shop environment.
The Athena Leva, in the hands of a master barista like Gwilym, can produce phenomenal espresso, but takes a little longer than the semi-automatic machines with which most American baristas are acquainted. The Athena also has a temperature variation in the exposed groupheads that can affect initial shot flavor, after a momentary pause in customer flow. For instance, if there’s a lull during the day, the groupheads get hotter than what is best for perfect espresso brewing. So, the barista may have to pull a shot, discard it, and then pull an espresso at the proper temperature. It is believed, and I have certainly experienced it, that the spring-assisted pressure variation of the Leva, is the reason for such phenomenal espresso. The initial preinfusion, followed by full pressure, which then ramps down until the shot finishes (about 30 sec.) can create a wonderfully balanced, tactilely superior beverage. However, this machine requires a lot of training for consistency, and because of the longer shot times, may slow down a busy shop.
I have encountered a mindset among baristas that basically goes like this: “Lever espresso = sexy but not practical. Super-automatic espresso = Evil, starbuckian devices designed to reduce the barista-craft to simply punching a button. Semi-automatic = Using the volumetric programmable buttons is a loser stunt. Manually cutting off the pump is more legit.”
So where does a machine like the La Marzocco Strada EP fit into this mindset? With its electronic paddle, the barista can control the preinfusion pressure and duration, the ramp up to full pressure and the speed of that ramp-up, and the slow drop in pressure as the shot finishes. This could mimic the pressure profile of the lever espresso machine. But it also allows you to program a pressure profile, allowing you to repeat the same exact parameters each time. Consistency… yay! Push-button espresso….wait, did that just happen?
To bunny-trail briefly in order to make a point: the Bunn Trifecta does something similar, allowing the barista to control water flow, temp, saturation, turbulence, brew time, etc. while also making these settings programmable. It works. You can get very consistent results, and great-tasting coffee. So the Strada is accomplishing a similar thing, only for espresso.
What the Strada DOESN’T do is dial in the grind, or verify the tamp pressure. Both of these variables are critical to producing a quality shot. And this is solely the responsibility of the barista, and ultimately hinges on the quality of training that barista receives, as well as the barista’s personal drive for excellence. The barista, or bar manager, or both, would also be responsible for determining the best pressure profile to program and choose based on the coffee being brewed on a given day. Coffee varies greatly in density and flavor, requiring shop managers and baristas to be knowledgeable about how a given coffee will extract.
Tamp pressure should be consistent. You don’t vary your tamp, at least, you try not to. So that leaves dialing in the grind and dosing. What affects this? Humidity, barometric pressure, bean density, etc. How do we keep this consistent? Currently, the only way I know is by extensive barista training, until they know how to consistently dial in the grind to the point it is capable of making great espresso.
What if the machine were able to make that determination? What if the espresso grinder, the portafilter, and the espresso machine communicated with each other, and the programming in the espresso machine were able to compensate for environmental elements based on the input it received from both the grinder and the portafilter?
Bear with me, and observe this as I imagine it.
The shop manager decides that today is going to feature a nice Ethiopian Single Origin espresso. So, the barista selects a pressure/brewing profile that seems appropriate, pulls a shot, tastes it, evaluates, then adjusts profile pressures/times to achieve the best results. Great so far, right? As the day progresses, weather begins to influence the extraction, and sensors in the espresso machine, grinder, and tamp acknowledge and adjust, based on programmed algorithms. The espresso never develops that frustrating mid-afternoon funkiness. Portafilter sensors ensure proper dosing and tamp pressure, with notifications visible onscreen before brewing takes place. Grinder notices bean density fluctuations, and automatically adjusts burr alignment to compensate, if very minutely. The grouphead sensors monitor water temp and pressure, and also note puck resistance, adjusting pressure if necessary.
Now, this sounds Jetson-esque, but I believe the technology is available today. We just need to decide if we prefer the Jetsons or the Flintstones.