[Homeroast] spinn?

Scace, Gregory E. Mr. (Fed) gregory.scace at nist.gov
Fri Dec 9 09:17:12 CST 2016

At 18 to 22% extraction yield,  no current espresso machine and grinder combination is currently capable of extracting more than 3/4 of the available dissolvable solids in coffee.  This is not due to taste desirability factors, but due to 1) the fact that available energy for extraction preferentially extracts the top of the coffee bed compared to the bottom, 2) the non-uniformity in concentration gradient within the coffee bed, which enables net diffusion of dissolved coffee across the boundary layer adjacent to ground coffee particles, 3) non-uniformity in size and shape of ground coffee, 4) pressure gradient across the bed of coffee, which is nominally 9 bars at the top and near ambient at the bottom.  Anyone who knows me knows that I am as hard core as they come with respect to espresso.  But I understand the current  limitations of espresso as an efficient method of extraction.  I find alternatives that could address fundamental deficiencies in the process to be very interesting.  The centrifugal extraction idea could address spatial non-uniformity issues inherent in the current process.  

The idea has merit.  Dunno if the execution can be good enough at the current price point. It won't matter if it can't produce the right temperature and grind coffee with a reasonable particle size distribution.  I'm skeptical that these things can be well enough executed in a $400 machine.


-----Original Message-----
From: Homeroast [mailto:homeroast-bounces at lists.sweetmariascoffee.com] On Behalf Of Steve Hamm
Sent: Friday, December 09, 2016 8:27 AM
To: A list to discuss home coffee roasting. There are rules for this list, available at http://www.sweetmarias.com/maillistinfo.html <homeroast at lists.sweetmariascoffee.com>
Subject: [Homeroast] spinn?

Not directly homeroast-related, but curious. Anyone developed an opinion on the Spinn coffee maker <http://www.spinn.com>? I'd expect hardcore espresso aficionados to call it a heresy, but it looks interesting (if a bit over-programmed).

Homeroast mailing list
Homeroast at lists.sweetmariascoffee.com
<a href="http://www.sweetmariascoffee.com/forum/">Sweet Maria's Forum</a> <a href="http://www.sweetmarias.com/library">Our new Coffee Library</a>

More information about the Homeroast mailing list