Thursday, February 2, 2006

Sending out an SOS: double pump style


I had the pleasure of stopping in at Gimme Coffee today. Lately Kevin seems to be splitting his time between Ithaca, Costa Rica, Brooklyn, and Idaho. How does he do it without collapsing? It's a trick I'll never master.

We retired to the roasting room in back, and Kevin began exploring the "extraction space" with their Leftist Blend. The back room has an original Faema E-61, which seems to be Kevin's favorite machine. He says the Faema takes a few shots to get in a groove, but then produces beautiful, syrupy shots. Here's a shot of it, not all cleaned up and shiny, but rather in full-on action mode:





Soon we switched over to their current Harrar coffee, which had been gently roasted to a nice, blueberry-preserving light color. I don't think Kevin was making any effort to play with brew temperature; that's not what this machine is about. Instead he was experimenting with the Sabadian, Bassetacious and Wendelboean variables of dose and headspace.

The Harrar was fruity, but it lacked sweetness and tasted a bit harsh. Kevin loosened the grind on the Robur and updosed a bit. The flow was very slow in starting. So he tried a trick I've never heard about outside of Gimme: when no drops appeared after six or eight seconds, he pulled the E-61 lever down to its mid (preinfusion) position. This turned the pump off, but left the 3-way valve in brew position and kept mains pressure on the group. After a couple seconds, he lifted the lever back to its regular, pump-on brew position.

In Kevin's view, this technique allows the puck to expand a little, and helps get a good flow going. Since a moderate amount of pressure is maintained on the puck, it doesn't blow up; it just "breathes" a little.




The results were really great. This cup was loaded with blueberries, sweet lemon, and a refreshing acidity. All the excitement of SOS (single origin shots) without the pucker factor. What a beautiful ristretto shot.

Is this double pump technique common knowledge? You'd think it might screw up the shot, but in fact it does not. I haven't seen it mentioned elsewhere.

3 comments:

  1. Andy, the PortaAndyFilter.org site rox since you started... great to see the interesting columns.

    My only comment... why, oh why didn't you do this for CG when I asked you to be a columnist years ago! LOL ;)

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  2. There certainly is this large organic-thermodynamic range going on. What a simple-sweet way to catch/surf the properties of the moment. Someone needs to build an accurate computer sim of these events then we can play with technical dynamism to our hearts content.

    Great write up,

    -a

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