Psyd wrote:Yeah, it's wacky, but you gotta try stuff. You just may end up, in your waning years, using a Centridistrofuge (tm)* to dose and distribute your morning espresso.

I'm with Cannonfodder on this one; you don't have to try everything. I will allow my portafilter to be put in a Centridistrofuge (tm) when they pry the portafilter from my cold, dead fingers.

Well, thanks to those who weighed in on the side of adventure. While I was mostly joking in my comment to Jon about an espressoporn showdown, I have to admit that my back hairs (how did you know I don't wax in the winter?) did prickle a bit in response to the perceived slap-down against the spirit of inquiry. I mean, this is the place where I first found charts of Total Dissolved Solids, and eye-popping temperature curves generated by $200 Fluke thermologging devices. But then I start wondering about the physics of powder distribution and, whoa Nellie, we're over the edge!

Well, cover the eyes of the Newbies, 'cause it's about to get technical in here. Those who are satisfied with their morning cuppa, and/or only have 45 seconds to distribute their coffee in the basket can go back to enjoying your coffee. We'll call you if anything interesting develops over here, that fits into your enviably brief HX routine.

One of the most important questions in distributing coffee properly is the role of "fines". Dan stated in another thread (which I can't find to save my life) that, in his experience, tapping the basket to excess tended to migrate the "fines" to the bottom of the basket, which produced an extraction that emphasized the flavor components ordinarily present in the first third of the pour. I believe he called it "front loaded". Of course this is only one person's (considerable) experience, and it would be nice to have some more data on this taste experience, but let's take it at face value for now.

The nice thing about vibrating a basket down to the maximum tapped density of the grounds is that you get a puck density, pre-tamp, that is consistent for a given substance. My source for that statement is the Autotap brochure, referenced in a previous post.

Who cares? Well it's got two applications:

1. Consistency of extraction - maximum tapped density and a flat surface means you've taken out airspace and levelled the puck. Ergo, there shouldn't be channeling. (In "Some Aspects of Espresso Extraction" Jim Schulman mentions the phenomenon of "microchanelling", I don't know what the devil that is, let's leave it alone for the moment until someone enlightens us).

2. Consistency across experiences - Use the same batch of beans, grinder, PID'ed machine, and a measured tamp, and you and have a remarkably consistent tool for comparing shots. (If you're really lab-technical you use a digital tool for measuring burr spacing, and you measure ambient humidity and and measure TDS and volumetric water dosage, and probably control for more variables that I'm not thinking of at the moment).

Anyway, it's one step closer to a reference standard for the puck.


Now Andrea Illy goes and complicates, perhaps even destroys, this whole theory, by telling us this interesting tidbit, on page 215, crudely summarized below:

An espresso puck is a heterogeneous ("plurimodal") mix of coarse and fine particles. The coarse bits create a structure that limits the water flow. The fine bits are what contain the flavor components. Therefore, a distribution that homogenizes the puck or separates it by particle size is going to be undesirable.


This may account for the flavor change Dan was noticing when more fines migrated to the bottom.


Thus, it seems that our goal is to create a uniformly distributed mixture. That's probably part of the reason why the WDT works so well. Nonetheless, we also want that mixture to be at maximum pre-tamp density without differentiation by particle size. Otherwise, when we press down that tamper, we're pressing on a surface with uneven pockets of airspace, and creating space for channels. If you're good, you can get close to that ideal with stirring (for clumps and mixing), thumping (for the bottom layers), and Stockfleth's (for the top) , and then the lovely E61 erases any lingering errors with a nice, gentle pre-infusion.

BUT....

I'm still betting that you can get an improved shot with some mechanical means that does the equivalent of sift/stir/thump/level all the way to maximum tapped density. And it should work well for those with less expensive equipment and less-practiced barista skills.

You'll still need a light tamp. Illy says so. How hard doesn't really matter, you just need enough pressure to release the oils and stick the particles together, which creates a more even resistance against the water flow. Sorry, no time to go back and find the page but it was contained within the 2nd or 3rd page of the search results for "distribution".

It seems like an ounce of experimentation here might be worth a pound of theory. I'm going to keep reading for now, but next month when I have more time I'll probably start messing around with vibration and spinning and maybe even vacuum suction. Anybody who has gotten similarly curious is cordially invited to experiment as well. If it doesn't work on our coffee, maybe Dr. Ruth will buy our patent.

~tMb

P.S. If anyone would be kind enough to save me $100 and loan me a copy of Illy's book for a month so I can quit trying to read it online through creative Amazon searches, I would be very grateful. Or I could offer a barter in the form of Barnes and Noble gift cards.


P.P.S. Again, gotta run no time to go back and find the page but worth looking at is the place where Illy discusses what a PITA it is to sift ground coffee because of the oils that stick different-size particles together.

I have just read this thread for the first time today, but ...

The_Mighty_Bean wrote:
It's documented on this site, by certain extremely experienced and well-regarded members, that hand distribution is unreliable and difficult

... could someone please help me understand the rationale behind this statement? This is not an attack on the individual who posted, but a general question due to the underlying theme that dissecting needles, yogurt cups, ramekins, paper clips, shakers, etc., are needed to prepare espresso without great difficulty. I honestly don't get it sometimes.

Peace.

AndyS wrote:I'm with Cannonfodder on this one; you don't have to try everything. I will allow my portafilter to be put in a Centridistrofuge (tm) when they pry the portafilter from my cold, dead fingers.

Cheers, and like I said, no one is telling you that you have to. that's still no reason to suggest that those that want to play and experiment are somehow ruining it for the noobs or desecrating a holy ritual or something. These folks are the type that have fueled innovation for millenia. Lots of them have died doing silly stuff, but those that have survived have been what's given us crops, domesticated animals as beasts of burden and a food source, indoor plumbing, the arts, HVAC, cars, radio, television, and espresso machines. Leave 'em play, I say.
Look, I haven't the time or the inclination to gather together three machines of nearly any sort here, but I'm so happy that some folks will. I don't have time to go through the experimentation required to devise a water dance for my HX, or a surf regimen for my Silvia, nor do I have the time to learn my lever from scratch. Nearly every detail of pulling shots that I've learned, I've learned from people like the ones considering spinning baskets. I let them do all of the work, and scroll down to the bottom of their threads, and get to the results. If they've come up with something that makes the coffee better, I try it. If it works for me, I steal it! It's these very folks and their efforts that made me the accomplished barista from the noob that I came here as. Of course, if I get to the bottom and they say it was a total failure, they've just saved me a whole raft of time.
Cheez, if it weren't for some guy like them, bored, out watching goats eat berries, we wouldn't even be here!

Matthew Brinski wrote:... could someone please help me understand the rationale behind this statement? This is not an attack on the individual who posted, but a general question due to the underlying theme that dissecting needles, yogurt cups, ramekins, paper clips, shakers, etc., are needed to prepare espresso without great difficulty. I honestly don't get it sometimes.

Quite often, some posters aren't able to afford the best machinery out there, and what they are able to get their hands on will sometimes have shortcomings. Some innovative person with more time than money will attempt to overcome these shortcomings, and when he does, he posts the secret, hold-your-tongue-right method of getting great results from less-than-stellar kit. It works, so others adopt it and have better espresso, so it becomes popular. If it didn't work, it'd die on the delivery table.
Some folks have superior kit from the get-go, so they don't see the results that those with the middle of the road kit will, so they don't understand the gyrations. Some folk don't see the difference between what they get with the additional technique and without because their palate will accept either result as good enough (bless them, I wish I were still one!) and they won't understand why you'd do those things either.
Those that want better and don't want to spend next years mortgage to get it will try anything, and adopt what works for them.

i think you would have time better spent on redesigning the grinder instead of the doser.

jon

The_Mighty_Bean wrote: I mean, this is the place where I first found charts of Total Dissolved Solids, and eye-popping temperature curves generated by $200 Fluke thermologging devices. But then I start wondering about the physics of powder distribution and, whoa Nellie, we're over the edge!

These things are different in that no one is proposing or trying to create these temp curves or charts as part of his/her morning routine. As far as shot-prep goes - most of the ideas proposed here at HB that are sorta outside of the normal cafe routine still consist of fairly quick moves or things that do not severely slow down the process. Remember - most of us have limited time in the mornings to prepare our espresso before work. We can tweak a lot of things in our free time that will improve the shots we pull in our pressed time but I personally have no room in my morning routine for elaborate processes added on top of the normal shot prep.

brad

Rapidcoffee, thanks for your comment. I have the same problems with shaking the basket. You end up with a nice dense puck but the distribution is uneven and hard to correct without one of those Australian downdosing scrapers I keep hearing about. I tried Stockfleth's for Dummies on those well-settled pucks, but I always end up with results that are less than perfectly level. Still, I've gotten some excellent, syrupy, high-TDS ristretto pours, using the shaken basket, plus some of your celebrated technique to re-fluff and level the top.

I also used a vibrator with poor initial results. I didn't detail all the crazy stuff I went through. I tried two weaker vibration devices before settling on the big plug-in back massager that I wrote about. Neither one of the smaller devices worked well, so I see why you gave up. But from trying the big one, it seems that sufficiently strong, vibration, centered under the basket, gets the grounds spinning in a vortex-like shape that looks a lot like a sloow version of the spinning part of milk-frothing. I bet that sort of strong, centered vibration, paired with rotation of the basket would yield a good result. That's where I'm likely to start experimenting.

Regulator, meant to thank you for the link to the thread about how deceiving looks of the pour can be. That was interesting reading. Also, re: your comment about best approaching this issue through grinder modifications, I think Versalab is doing a great job at that, for $1500 and up. And they have said clearly that it is their intent to keep costs down, but retain design quality. Frankly, I haven't the tools, nor the first idea how to improve on an espresso-quality grinder, let alone how to do it for under $100.

But spinning and vibrating and vacuuming- all those things can be done quite inexpensively, and they're simple for us to mess around with at home to see if they improve the pour.

DigMe - agreed, and my goal is to come up with something quick, practical and cheap.

Matthew - did Chris answer your question?

Psyd, thank you for your kind words and eloquent defenses of innovation. You're absolutely right. Nobody here knows this, but I invented the internets.

~tMb

Psyd wrote:.........
In any case, if you were to put the entire basket on the inside of a spinning thing, with the opening of the basket facing the center of the rotation, would it distribute any better or simply be a very complicated method of 'thumping'?

"HEY! Why are all those portafilters embedded into the walls and ceiling? And why do you wear that helmet when making espresso? And what ever happened to your dog?"

Randy G. wrote:"HEY! Why are all those portafilters embedded into the walls and ceiling? And why do you wear that helmet when making espresso? And what ever happened to your dog?"

I don't know, but it all came to a sorry end when my wife left me and ran off with my vibrodistrocentrifuge.