Archive for the ‘ Science ’ Category

Gwilym and the Athena Lever Machine

Love your Lever

Ever wonder where the expression “pulling a shot” comes from?  Maybe not, but this is where; pulling the lever of a piston driven espresso extraction.  The first espresso to have thick and persistent crema, heavy body, and a tasteful balance between acidity and sweetness, came from the lever design.  At a time when the Italian infrastructure was mostly demolished, (1940) cafes needed a way to bring water to the espresso machine (previously steam driven espresso) when there was no running water.  The solution, designed by Gagia, ( still a name in espresso equipment today) was to put the water pump right at the point of coffee delivery.

Cosimo Libardo and Lou Barba of Nuova Simonelli, traveling with Gwilym Davies, are presenting the Athena lever machine in the USA this week.  I attended the event in Washington DC at the Counter Culture Coffee training center.

It is basically the same type of low tech water pump you see in old cowboy movies where the thirsty character has to drive a handle up and down to make the water flow.  Simple enough, right?  It is simple, very simply, so simple it is almost stupid.  Purely by accident, this innovation implemented so many serendipitously positive characteristics that it becomes mind boggling.  Here is a short list:
-The first espresso ever extracted above 2 or 3 bars of pressure, the lever delivers an average of about 9 bars along a declining graph of pressure over time, resulting in the first crema

-Drawing super heated water from the boiler into the piston chamber brings the temperature down to an appropriate range, with a descending temperature throughout the life of the shot

-Soft, slow, and gentle pre-infusion at 0 bars of pressure, which you can time as long or as short as you like

If you think about all the technological advances since this 1940 design, (electric pumps, double boilers, mechanical and electronic pre-infusion, gicleur regulated soft infusion, and pressure profiling),  all seem directed at reproducing what this simple device does in a natural way.  Let’s have a peek:

ATHENA LEVER

It does all these same things, but in a way that is slightly different than what we have become accustomed to.  It stabilizes temperature, but not in a flat line sort of way.  The temperature starts high and dramatically drops; as much as 10 degrees F.  It pressurizes, but again not in a flat line.  Pressure starts out a phenomenal 11 bars, and dramatically drops as low as 7 bars.  It pre-infuses, but with 0 pressure.  The differences are such that you can’t apply what you know from electronic machines.  Pre-infusion is long, the shot itself can run very long, and you have to really go out of your way to channel or over extract.  In fact, watching Baristas work on it for their first time, I was struck by how difficult it was for them to allow the shots to run 40 seconds or more.  Second nature for them was to terminate the shots before they were fully developed (thinking they had already over extracted).  Once you get the hang of it, however, you find that the high temps and pressure at the beginning coupled with low temps and pressure at the end will result in brilliant acidity balanced by intense sweetness.

Love your Lever

Nuova Simonelli bought the Victoria Arduino brand a few years ago, and have retooled the design to include a heat exchanger (it was drawing right from the steam boiler before) and some other small tweaks.   Cosimo is very intent about studying all aspects of their equipment in a scientific way, designing and redesigning equipment with the production of great tasting espresso always in mind.

Love your Lever

I have always been drawn to low tech and old fashioned ways of doing things.  My fascination lies with how problems were solved in such simple ways before humans had developed the incredible tech boom of the last 50 or 60 years.  I am in love with this machine and the simple technology on which it works.  With a gas flame, you can run this thing entirely without electricity.  Wrap you bicycle chain around the drive shaft of your espresso grinder, and you have the total package.

Oh Wonderful Podcast

I just don’t know what I would do without the Podcast. It makes the hours in my cubicle just whiz by as I listen to the latest scientific viewpoints, technological developments, and the arguments put forth by the religious community. Oops, I didn’t meant the PF Podcast, I’m talkin’ ’bout Dr. Zchary Moore, Ph.D.’s Evolution 101 Podcast. I have been listening to thing for the last few weeks, and I am riveted. It reminds me of watching an episode of Cosmos, Carl Segan’s old PBS series.

I don’t care what your religious or spiritual viewpoints are, this guy is worth lending you ear. Maybe next week I’ll turn you on the Urantia Book, too. That is a whole different world.

Darwin chimp

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