Re: Crackin' this market

Hi Al,

I copied out your text, and I'll address the bits now.

Thanks for your response. I am not that familiar with your device, and
if it would have applications outside the realm of LM's.

It's applicatble to any machine that uses a 58mm portafilter. Ya gotta
chop off the bottom of the pf in the "crotchless" style.

My Fluke,
although bulky does a good job, whether measuring in the cup or at the
output, which is my preference.

The device is better than measuring at the output because the
measurement doesn't include heating of the coffee cake. It also isn't
influenced by the temperature of the spouts through which the coffee
pours. Such influence is related to the use of proper brewing
technique, or lack of it.


I'm pretty sure I heard an interview with you on a podcast, and have
heard really good things about your device.

On portafilter.net last november.

Perhaps a reintroduction here would be beneficial to some of the
newcomers, and increase awareness of your product. I, for one, would
be very interested in reading a current description, where it has
affected the market, especially in your own words and not some
reviewer or reseller. I would be interested in your estimation of its
performance, how to interpret results, etc.

Here's a recap of the Deevice. It's a modified filter basket that
contains a type T thermocouple probe, which is located above a plastic
insert that simulates the coffee cake. The insert fills the volume of
the basket, supports the sensor, and has similar thermal
characteristics to ground coffee. There's a chamfer in the top of the
insert that collects the hot water and directs it to an inlline filter
(Barry's contribution - He did that part ..... right there!), which is
upstream from a simple flowmeter that sets the flowrate through the
deevice. When used as directed, the pressure buildup and flowrate
through the group are nearly normal, as compared to actual brewing.
Pressure builds to 9 bars and flowrate is comparable to brewing a
double shot, including the water that is absorbed by the cake, which of
course ain't absorbed by the plastic insert. The geometry of the
insert is such that the hot water moves on through at a flow rate that
doesn't encourage a whole lot of mixing (that means that the volume of
water that is collected above the filter is only a few ccs), which
means that the thermometer doesn't get cooled by downstream water. So
it does a better job of measureing water temperature as it leaves the
group, and before it hits the coffee, than does a thermocouple that is
lying on top of the coffee cake. And it's real reproducible.

WRT its performance - The accuracy of Type T probes that use standard
wire is +- 0.8 Degrees C. I'm using probes that contain "special
limits of error wire", so they are better than that in terms of
absolute accuracy, but by how much I dunno. the .8C number is
conservative. In terms of reproducibility, the devices repeat to the
tenths of a degree level. Accuracy of the combined system of deevice
and readout has to be assessed depending on the readout device. Dunno
what Fluke actually specs, but it's good enough that we can talk about
specific temps for specific coffees and translate the number from
machine to machine, quickly tuning machines for a specific blend. I
did a domonstration of this during Espressofest, which was the C-member
thing at Counterculture Coffee that was held during the SCAA
conference. It's particularly effective when tuning machines of the
same type because one then doesn't have to consider differences in
pre-infusion style, pressure buildup rates, or other things that may
also influence the extraction. At Espressofest, we tuned different
machines for the specific coffee blend and got reasonably close very
quickly, even though we were sweeping the pre-infusion thing under the
rug.

In terms of its impact on the market, I am just tickled to death that
it has gained acceptance in the industry. It's being used as a
roaster's tool to translate desired brewing temperature specs to
machines being used in shops to transform specific blends into yummy
drinks. It's being used as a machine setup tool, a maintenance tool,
and it appears that plenty of trainers are using it to teach people how
to use equipment. What was very cool for me was to learn that Nuova
Simonelli had bought a bunch of them and that they used it to develop
the Aurelia, which is their new uber-stable heat exchanger machine. If
you'd have asked me last year whether or not a HX machine could produce
consistent brewing temps time after time in wildly varying duty cycles,
I would have said "No way!". But the NS guys have done a very good job
on the Aurelia and the measurements that were demonstrated over the
course of the SCAA show demonstrated that a HX machine is actually
capable of producing stable brew temps over variable duty cycles. The
largest contributor to instability in the Aurelia is the temperature
swing due to pressurestat cycling, and not anything related to the
temperature difference between the boiler water temperature and the
temperature that is correct for brewing. I was floored. When I
measured a Simonelli about 2 years ago, the thing started out at 210
degrees and got pregressively colder duiring each shot, bottoming out
near 180. Now these guys have their act together! Barry had a look at
the Aurelia and he was pretty impressed as well. Anyway, I was pleased
as punch that Simonelli was so enthusiastic about the Deevice and that
the Deevice could have an impact on espresso machine design. I haven't
run the WBC test protocol on the Aurelia, but I bet it's only
marginally less stable than the Marzocco GB5.

WRT predicting results - obviously there is more to producing a good
cup than just temperature. However, let's assume that the raw
materials are good, e.g. fresh coffee that is sourced well and blended
well, and let's assume that barista technique is sound. That leaves us
with pressure, temperature, pre-infusion, and some geometric
constraints imposed by filter bsket / portafilter design, and the
design of the group. Let's assume that the group design isn't hideous
because that's intrinsic to the machine and we can't do much to fix big
problems there when we're tuning. But we can select reasonable basket
geometry (since I havent' done research here, and since I don't make
baskets I defer to Illy), temperature, pressure, and pre-infusion.
Unless pressure is hideously out of whack, temperature is the biggest
influence. The deevice makes it really easy to measure temperature
very well, allowing one to easily tame this particular variable, and to
demonstrate brew temperature to folks who maybe ain't believin that
temperature is a big cause of their troubles.

Sounds like in you particular case, temperature problems ain't the only
problem facing this shop.

Hope this helps.

-Greg


I avidly read anything you write. If you have the time, I would
appreciate hearing from you about what has transpired to this date,
and how this device has performed, based on your own standards.
All that having been said, I have very few LM's in my market, and
haven't worked on one for over 10 years. I understand that they are
considered the standard for quality, but so far I have not been
impressed. The only good shots from them that I have had have been
from Dr. John. I am certain that is not the fault of the machine, more
likely the operator.
Something is definitely wrong with the machine I wrote about earlier.
How do you adjust boiler temp on these machines? I would at least like
to be informed as to how to correct his problem when it comes to that.
I am perplexed as to how a machine that runs cold at idle, could still
have an impact on my tongue today....al

.

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