Shifting Variables: The EK43 and Pressure Profiling

by Zayde Naquib

There has been much discussion within the coffee community about the use of the Mahlkonig EK43 as an espresso grinder since Matt Perger, with the coaching of Ben Kaminsky, flipped espresso preparation on its head at WBC last year.  Being something wholly new, it sparked opinions greatly positive and extremely skeptical.  As we prep Bar Nine for our official launch, I thought it would be a good time to share our thoughts with our experiences.

Our set-up: Modbar espresso units + Mahlkonig EK43.  First, in speaking of the EK, it is now abundantly clear we are pulling a different kind of shot.  It has to be as our extraction percentages have changed dramatically, 21-23% being the range.  In addition, the dramatic reduction of fines, enables us (or forces us, perhaps) that we grind much finer than what is traditionally used for espresso (we’re talking “Turkish-level” here).  What does this mean in the cup?  Well this is where the answers get simultaneously vague, at-times frustrating, and other times increasingly exciting.

Looking at more traditional 9-bar extractions, these are rounder, sweeter, and clearer than before.  You can extract more, which means “luongo” can be pretty tasty with the right coffee.  And if you serve a very lightly roasted coffee as we do, this is a good thing, because curbing shot volume is very difficult.  You’re basically always operating at the finest possible setting.  There are ways to compensate: the now infamous nutating tamp, or otherwise throwing traditional parameters out the window and going for a new kind of definition for espresso.  This is acceptable, but as a barista who agonizes over control, the answer lies elsewhere.

What it seems to boil down to for me is an altered balance of both constants and variables,  The definite constants before were dose/beverage weight as well as brew temperature and pressure.  Your variable to achieve your goals became adjustments to grind setting.  (The aforementioned is assuming these are our accepted starting goals in quality-oriented cafes).  The way to bring control back into the process is to add grind setting to your constant list and having brew pressure become the major variable (we have our EK pegged at its finest grind setting).

We’re using Modbar, which has a very similar internal set-up to the La Marzocco Strada EP.  Essentially, we have 5 stages of profile control at our fingertips, as well as max and minimum pressures, rinse cycle, and volumetrics.  We’re using all of them, which takes a lot of work.  Suddenly, your simple brew recipe with a single variable of grind size to achieve desired yield becomes a multitude of variables where our goals have shifted entirely.  Sure, extraction yield still plays a role in how we craft our profiles, but the biggest thing is we are exploiting everything beautiful our coffees have to offer.  Pressure profiling can open doors for new and improved flavor anyway, provided you know how to manipulate it, but with extractions at say 18%, these are glimpses of flavor possibilities.  Extracting at the high percentages we are is where flavor really starts to pop.  Take a high-acidity Kenyan that can be abrasive as espresso, turn it into canned peaches with sparkling acidity and syrupy sweet finish with a 45 g beverage weight.  Exploit the sweet glory of a vuluptuous bourbon from El Salvador, pulling a lever-style normale.  These differences in extraction are simply more pronounced with clarity rivaling that of a great filter brew.  The possibilities are endless.

To wrap it up, in order to put out what you want as a barista, having variables to alter is paramount to the control in flavor presentation we want.  By shifting those variables to profiling coupled with an EK43, I firmly believe we can make a more distinct personal stamp on the coffees we serve.  Is it for everyone?  Definitely not.  Probably not for most in fact.  Designing a work flow around a grinder used for spice milling presents other challenges.  The simultaneous amount of control and the surrender of other controls (ie, grind setting) can be daunting, but once you start tackling it, look out.  Your palate will thank you.