COFFEEJACK, The Pocket Sized Barista (Kickstarter)

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kmonroe99

#1: Post by kmonroe99 » Nov 05, 2019, 10:29 am


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yakster
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#2: Post by yakster » Nov 05, 2019, 10:35 am

I can't see from the video how it would develop sufficient pressure for real espresso. (Viewed from my phone)
-Chris

LMWDP # 272

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redbone

#3: Post by redbone » Nov 05, 2019, 11:06 am

yakster wrote:I can't see from the video how it would develop sufficient pressure for real espresso.
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549

John49

#4: Post by John49 » Nov 05, 2019, 11:39 am

yakster wrote:I can't see from the video how it would develop sufficient pressure for real espresso.
The piston diameter is small, so the force on the piston to generate 9 bar, at the puck, is small. However, the volume displaced is also small and would require multiple strokes per shot.

chipman

#5: Post by chipman » Nov 05, 2019, 11:46 am

If this thing is for real, I think it is a very cool little espresso devise. I'm looking forward for some more info.

dmw010

#6: Post by dmw010 » Nov 05, 2019, 1:46 pm

I noticed near the end of the campaign listing that the creators tout their experience bringing Kickstarter campaigns to fruition - but all of their previous campaigns are for pens and pencils (and a pocket knife). So they've got a track record but no experience with coffee, but at least there's a good chance they will actually produce the product (unlike some infamous coffee crowdfunding projects).

vit

#7: Post by vit » Nov 05, 2019, 1:49 pm

yakster wrote:I can't see from the video how it would develop sufficient pressure for real espresso.
There are devices with even smaller pistons developing sufficient pressure. Called vibe pumps :D

However, there are already manual devices with quite similar, just slightly longer pump. Called 1Zpresso Y3 presso (currently in 3rd version I think)

Considering water quantity, this looks like just another device possible of brewing some kind of coffee considerably below usual espresso temperature range

And not sure I would feel safe near the plastics of that thickness under 9 bar (or even if only 6 bar ) either

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doublehelix

#8: Post by doublehelix » Nov 05, 2019, 1:53 pm

This gizmo looks brilliant--curious about how many strokes are required for an espresso?

vit

#9: Post by vit » replying to doublehelix » Nov 05, 2019, 2:04 pm

Too much I suppose

As I mentioned a few times, I was using a home made espresso device for a while, consisting of 1cup moka express clone and bike strut pump. It was (is) able to achieve 9 bar (went max to about 11 bar once). However, for something like a single dose I needed 30-40 strokes. Air is unfortunately compressible. Good thing was - at least 7-8s was needed to achieve 7-8 bar by pumping max speed, so not much problems with too quick ramp up and channeling

That strut pump has 10mm piston diameter and stroke about 145mm. Considering this one is considerably smaller in both length and diameter, you calculate ....

But it should be capable of making something like small dose aeropress style coffee ... :P


Yeah, actually checked the video now. I thought it was just a short animation that was playing

It looks like pump is actually pumping water, not air like (I suppose) in Y3 presso or my "device"

In that case not much strokes needed, however, pressure will be varying a lot and piston and "brew head" will cool down the water. Can't see how to preheat that plastics. So end result not much better ... but at least no danger of plastic chamber exploding

There was also one device working this way, nomad espresso or something ...

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truemagellen

#10: Post by truemagellen » Nov 05, 2019, 2:06 pm

bespoke, bespoke, bespoke

I always want these types of things to succeed and find some magical solution to portable espresso but consider the following:

-their bench testing reference machine appears to be a De'Longhi consumer appliance that they have just taken the cover off of
https://www.amazon.co.uk/DeLonghi-Pump- ... B004INNKPC

-they are pumping the device vigorously to get the desired pressure disrupting the coffee bed in the process

-tamping with the dispersion screen is part of the design

-spending considerable time promoting eco friendly mumbo jumbo by saving paper cups going into landfills yet espresso is rarely consumed in a disposable cup (I know it is just marketing but still)