Finger Swipe Dosing ==> Sub-Par Shot? - Page 5

Beginner and pro baristas share tips and tricks for making espresso.
User avatar
malachi

#41: Post by malachi »

Among the many people who have seen the footage is James Hoffman. He's posted on here periodically, feel free to ask him about it.
I've seen screen captures from it and I've seen the write up done by the folks who did the research.
You can also find a ton of research available from the Association for Science and Information on Coffee (http://www.asic-cafe.org/index.php).
"Taste is the only morality." -- John Ruskin

User avatar
malachi

#42: Post by malachi »

If you can't ask James - you could ask anyone who was involved in the 2006 SCAE Euro Team Challenge. Luca from La Spaz showed the video to all the teams who attended.
"Taste is the only morality." -- John Ruskin

User avatar
another_jim (original poster)
Team HB

#43: Post by another_jim (original poster) »

The only ASIC contributions are two papers out of Illy's labs, one by Petracco, one by Capuccio, which describe simulations of the espresso extraction. The chapter I quoted has them in the bibliography. The Capuccio paper mentions particle expansion as it wets, and then mass diminution as it brews, but doesn't explicitly mention puck volume. It does mention that the particles don't shrink, rather lose their innards to become cellulose skeletons. That suggests the puck does not collapse during the extraction.

The video by La Spaziale, on the other hand, has not been followed up by any peer reviewed article I know of; nor is the video available for inspection. This makes it a prime example of internet hear say. Given that the Illy volume summarizes the known published science as it stood in the early 2000s, I'd say it's a bit premature to call puck expansion a myth.

This is actually not all that difficult to check, since we have a few people who have mounted pressure transducers inside the group. A pressure transducer at the top of an overdosed puck and under the shower screen would according to Petracco go off the charts as the puck expands to its rock splitting pressure levels. If the LS video is true, it would stay at close to zero until it got sucked out, like Goldfinger exiting his plane, as the three way valve whooshes.
Jim Schulman

User avatar
malachi

#44: Post by malachi »

Actually, I think there is additional research post Illy that's been presented at ASIC events.

Seriously, talk to James.
"Taste is the only morality." -- John Ruskin