Bezzera Strega - Second Look - Page 2

Behind the scenes of the site's upcoming equipment reviews.
ilVecchio

Postby ilVecchio » Sep 16, 2011, 2:40 pm

I absolutely love what the Strega can do, and Jim is completely consistent with his shots.

When I owned an Elektra lever, I could pull a truly great shot every 10 pulls or so, but could never get consistent.

Joel

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peacecup

Postby peacecup » Sep 17, 2011, 3:25 am

Nice videos Jim. Made me feel like I was there tasting the espresso with you.

One of my long-standing theories is that there is a fundamental difference between pump and lever machines in the way in which they apply pressure to the puck during both preinfusion and extraction. I have always supposed that that the low-pressure preinfusion, followed by the relatively laminar pressure applied by the piston face during extraction, makes it easier to get good extractions without disturbing the puck. My theory is that this is why there are miles and miles of extraction-problem discussions on pump-machine forums, but none such on lever forums.

As Jim rightly points out, lever users trade-off this ease of extraction quality against a very limited control of brew temperature. Only open-boiler levers allow precise temperature control, and there are none currently in production. When one finally does become available, it will offer the best of both worlds.

One final comment - with the exception of pump preinfusion, how does the ability to control brew pressure differ between the Strega and the several widely-used home lever machines?

PC
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

espressotime

Postby espressotime » Sep 17, 2011, 4:51 am

First shot with the Strega this morning:
click:
http://s143.photobucket.com/albums/r156...002-85.mp4

It produces great espresso and cappu's and is very consistent.
love the machine.

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another_jim
Team HB

Postby another_jim » Sep 17, 2011, 12:26 pm

Bob_McBob wrote:It would be nice if they all shipped with such a good portafilter fit. The portafilters on the Strega I'm using right now require a lot of force to lock in safely, and the fit is not really very satisfactory.


I filed the ears a little. The idea is to make sure the PF screws in far enough that it doesn't unscrew by itself.

But I agree this is not an optimal solution: Bezzera is one of the companies that has been around so long they assume everyone has an espresso tech on the block, as if they all lived in a North Italian city. They should know that when selling to world wide consumers, the machines should come out of the box with no tuning and fitting requirements.
Jim Schulman

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another_jim
Team HB

Postby another_jim » Sep 17, 2011, 12:29 pm

peacecup wrote:One final comment - with the exception of pump preinfusion, how does the ability to control brew pressure differ between the Strega and the several widely-used home lever machines?


The home spring levers don't develop 10 bar pressure, and holding a consistent pressure on a manual is harder (at least for me). The pump preinfusion allows one to pressurize anywhere from 0 to 9 bar prior to having any flow.
Jim Schulman

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HB
Admin

Postby HB » Sep 17, 2011, 12:32 pm

another_jim wrote:I filed the ears a little. The idea is to make sure the PF screws in far enough that it doesn't unscrew by itself.

For what it's worth, the evaluation Strega that I received required no portafilter modification and it locks in the usual straight-ahead position without undue force.
Dan Kehn

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drgary
Team HB

Postby drgary » Sep 17, 2011, 2:25 pm

another_jim wrote:The home spring levers don't develop 10 bar pressure, and holding a consistent pressure on a manual is harder (at least for me). The pump preinfusion allows one to pressurize anywhere from 0 to 9 bar prior to having any flow.


After watching Jim's demo, I wondered whether someone without a Strega but with a hefty spring lever or even a manual lever can ramp up pre-infusion pressure. I came across this by Doug Garrott in the original Strega thread, have tried his method on my Microcimbali and am getting nice ristrettos.

orphanespresso wrote:... I have been grinding in such a way as to not get any drips of espresso on preinfusion and pulling the lever down 1, 2, 3 or as many times as it takes to get the lever to be as low as possible on the stroke thinking that this will maximize the pressure on the puck...with each pull a bit more water is gulped into the cylinder and massaged into the puck at ever increasing pressure, but obviously a non linear pressure profile due to all the pulls...more of a stair step profile if done on a graph. I get the sense of extracting the 5's, 7's and 9's and then of course the reverse on the downpressure side of piston travel. And the heart of the crema arrives much later than the first parts of the pull.


Doug added:

orphanespresso wrote:... as an old school type ... the wheel seems to be not quite reinvented here, just a bit tweaked.


In that light, I wonder if a commercial lever with its full-strength spring can also be coaxed to make "impossible espressos" like the Panama Esmeralda Geisha? (And thanks, Jim, for demonstrating how to slow down the lever pull.) The ramp up using Doug's step method is obviously not as smooth as with a vibe pump, but with careful application, it may work. Or am I missing the something that's not there for pre-infusion pressure in a traditional commercial lever?

Other related musings: Are major Strega advantages its consistency/repeatability and the way these allow one to trust playing its variations like with a fine musical instrument? The Strega is obviously a home machine with the pour-over tank and single group. In a commercial environment where a single coffee is usually dialed in for that day, would one need its easy and repeatable variability to prepare challenging coffees?
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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another_jim
Team HB

Postby another_jim » Sep 17, 2011, 3:34 pm

DrGary wrote:Are major Strega advantages its consistency/repeatability and the way these allow one to trust playing its variations like with a fine musical instrument? The Strega is obviously a home machine with the pour-over tank and single group. In a commercial environment where a single coffee is usually dialed in for that day, would one need its easy and repeatable variability to prepare challenging coffees?


I don't think what I'm doing, or what any manual lever operator does, has direct commercial application. My thesis is that the Strega fulfills the promise of highly individuated shots. Also, if steadying the flow is the best heuristic for controlling pressure; it also means the way variable pumps are used in the new generation of commercial espresso machines needs to be reconsidered.
Jim Schulman

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drgary
Team HB

Postby drgary » Sep 17, 2011, 4:55 pm

another_jim wrote:I don't think what I'm doing, or what any manual lever operator does, has direct commercial application. My thesis is that the Strega fulfills the promise of highly individuated shots. Also, if steadying the flow is the best heuristic for controlling pressure; it also means the way variable pumps are used in the new generation of commercial espresso machines needs to be reconsidered.


another_jim wrote:The home spring levers don't develop 10 bar pressure, and holding a consistent pressure on a manual is harder (at least for me). The pump preinfusion allows one to pressurize anywhere from 0 to 9 bar prior to having any flow.


Jim and others,

I don't think I expressed one of my questions clearly enough. Many of us have small commercial levers at home, so we do have the full spring strength, the commercial-sized basket, and good temperature stability (can't wait to get my Conti Prestina up and running, but still waiting for parts!). For those using such machines at home, how much advantage might be had with the Strega's innovative hybrid of pump and lever? Is "the difference that makes a difference" repeatability? Is the smooth pressure ramp-up of a mechanical pump versus the step ramp-up of multiple lever pumps an important difference? I think for the latter we might need to taste test a Strega versus a traditional commercial lever with a similar group.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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another_jim
Team HB

Postby another_jim » Sep 17, 2011, 8:54 pm

That is an excellent question; thanks for asking. I'm not sure about the answer.

I spent a day with the Victoria Arduino lever, which has the same Astoria/CMA group and runs via an HX and mains connection. I got shots with thick mouth feel but very flat and mild taste. However, I was not able to retard the lever or control the grind settings and dose like I do to get the repeatatably great shots from the Strega. I've had shots from the Slayer and Hydra that are like what I'm getting from the Strega, but never from any other lever machine.

However, pressure profiling machines are in the process of changing the rules of espresso. This means the traditional ways of operating a lever machine are not relevant, and the question becomes if levers can be revived as pressure profiling instruments. This is a new and very different way of thinking about them. I am going to learn and report about the Strega in this context. It may be that some of the things I do with the pump can be done with a line connection and no pump; but I'm not going to investigate this.

There are at least a half dozen commercial single group lever machines people can buy if they believe the Strega pump serves no purpose; and there are hundreds of out of production machines they can restore. I'm glad you linked to Doug's tips for using these machines; and I hope that people post their experiences of making state of the art espresso on these machines.
Jim Schulman