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AeroXpress, a "lever" AeroPress

Postby Quadrifoglio on Sun Jun 22, 2008 2:35 pm

In pursuing a finer grind for the Aeropress, the pressure needed to press the coffee kept going up. When the grind size got fine enough to require my arm and body weight to press the coffee, something had to give. Also, I almost launched the press, container, and coffee across my desk when it got a little off of vertical.

My solution was a bit of "found item" engineering. As you can see, it is (was?) a juice press. The only modification was to replace the original 7/8" x 12" rod with a 20" stainless rod. This was to accommodate the AeroPress fully extended and use the existing parts. The AeroPress rests on a 4" snap in floor drain with the center cut out that actually does snap right in. After the photo was taken, a funnel was added to control splashing. The middle funnel from a Big Lots set of 3 drops right in. There is a silicone pad in the cone to cushion the AeroPress.

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With a full load of four scoops of coffee, there is plenty of travel. To do a double, the platform has to be moved up and the plunger pushed in by hand a half-inch or so. A couple more teeth would have been nice.

Since the proof is in the pressing, here is the first shot. It is a scoop and a half (21g, give or take) of Big Bend Coffee Roasters Ethiopian Yirgacheffe and 3 ounces of water. Mixed for 10 second and pressed. Thick, smooth, and tasty.

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However, for the sake of completeness, I did try tamp and press.

With a double in the cylinder, the AeroPress is capable of 6.5 bars by compressing the air gap to 0.5", 8.5 bars at 0.375", and 13 bars at 0.250". I didn't measure the pressure but used P1 x V1 = P2 x V2 to calculate it. I ignored the effect of temperature in the calculation.

A Lawry's seasoned salt shaker contributed its cap and with an 1-1/2 piece of PVC pipe and a rubber band, a tamper was born.

Despite my AeroPress being older and inconsistently venting past the plunger. I was able to make a few shots. Also, the AeroPress vents grounds out the side of the filter holder at the higher pressures.

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The crema was thicker but less of it and it lost a lot of the notes in the coffee.

I will stick with the mix and press method. I think it makes a more interesting cup of coffee.
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Quadrifoglio
 
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Postby tarawa on Fri Feb 06, 2009 4:16 pm

That is really cool. Great job!
tarawa
 
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