KarlSchneider wrote:Jim,

Great story. I can see some parallels to my experience with my Elektra -- especially in the single shot preference.

If you really want a eagle taking flight I can let you have mine. I much prefer the blue Murano glass ball on yours and on my Microcasa.

KS

No thanks, the Murano "sort of" fits, the Eagle not at all. What it really needs is a miniature of a polished modern piece of sculpture, perhaps a mini-Millenium Park "Bean" from a souvenir store.

joatmon wrote: We have our first recorded case of "downgrade fever"!

Technically, the Semi is a tad dearer than the Tea or other basic E61 boxes. Appearance-wise, it simply rules: A steel E61 box is pretty striking when it comes to "visual dominance." When I put in the M3 grinder, that was the first thing the eye went to; but the M3 looks plain-jane next to this espresso sculpture.

Also given that it heats up, rather than cools down, when making shots at a fast pace, it's "cups per hour" rating would be much higher than any semi-commercial machine. Remember, the shot temperature graphs I posted were done on the following wbc-test derived schedule (also I don't remember seeing any wbc test graphs, straight or modified, except Andy's Silvia, which I freely admit is more stable than this machine):

But when it comes to features like gauges, water taps, opvs, electronics, etc; it certainly is a downgrade.

Finally, my subjective opinion is that it improves significantly on the E61 box for shot taste. The "significant" part is quite unlikely to remain my opinion once the honeymoon is over. However, Mark spent a year reviewing this machine, and had lots of people over sampling it. They all thought it was a very strong performer compared to other semi-commercial machines. Once the Tea is repaired and instrumented, I'll set up a blind tasting shoot out with local espresso people, who can also bring by their contenders.

another_jim wrote:Once the curves are stretched to coincide in time, there's about a 1.5C to 2C inter-shot variation. Intra-shot variation is 5C.

It is a lovely machine; I'm with Karl - the Murano glass is the perfect topper.

Isn't this roughly the (temperature) performance expectation of a Gaggia?

A 1C temperature change on my BII is a clearly distinguishable difference - not just to me, but to everyone who has tried back-to-back shots from my machine. 5C variance within the shot pretty much says that temperature is irrelevant, as long as those 5C are within the coffee's comfort zone. And yet I can show how a shot can go from sweet to unpleasantly bitter within 3C on my machine with many coffees (as read from the BII's LED).

Or is Dan suggesting that what we are interpreting is a measurement phenomenon for Jim's PF setup?

I'm confused.

Mark

Dogshot wrote:It is a lovely machine; I'm with Karl - the Murano glass is the perfect topper.

Isn't this roughly the (temperature) performance expectation of a Gaggia?

Read the protocol, get a Scace device, or set up something similar for K type probes, run it with the 2 second or 2 second past boil flushes on your machine or a Gaggia, then talk. Machines have a way of looking rather bad on this test

A 1C temperature change on my BII is a clearly distinguishable difference - not just to me, but to everyone who has tried back-to-back shots from my machine. 5C variance within the shot pretty much says that temperature is irrelevant, as long as those 5C are within the coffee's comfort zone. And yet I can show how a shot can go from sweet to unpleasantly bitter within 3C on my machine with many coffees (as read from the BII's LED).

Or is Dan suggesting that what we are interpreting is a measurement phenomenon for Jim's PF setup?

This is where it gets interesting.

On machines with relatively straight line profiles, changes of 1C, or 1.5C for us dull tongued types, begin to systematically change the taste. As a profile gets more humped, the range of adjustabilty goes down, since pretty soon the hump or the low start and end points will be outside the brewing zone. On the Elektra, the hump is 5C, and any adjustment will take part of the curve out of the comfort zone. Hence it basically allows no temperature adjustment (compensating changes on boiler fill level and pstat setting may change the curve). The profile repeats fairly accurately shot to shot, so that multiple shots will taste roughly consistent; but if a coffee does poorly, one can only play with the shot volume and time.

Michael Teahan prefers the hump, despite its adjustability problems for two reasons:

1. An initial spike may heat the puck more efficiently. This is what Dan was talking about. However, with respect, it's not what's happening here. The Elektra has a symmetric hump, rising slowly, and falling slowly. Its effect on the middle of the puck may be no different than a straight line profile through its average temperature point.

2. Brewing the puck through the entire temperature range may get more out of the coffee than any single temperature. This is what he was saying at his SCAA and Homecoming talks. In other words, you can adjust your BII or GS3 through the entire range, drink a dozen shots, and not get a single one as good as from some old line, "temperature all over the place" machine. In other words, Schomer's seminal article about "mediocrity by design," which started the trend towards tightly controlled brew temperatures, and all the subsequent work done here, may have been based on a false assumption, or at least one that needs to be heavily qualified.

One problem is when one asks Italian espresso people a question, they reply as if they are humoring little children; and this is especially true if they have no idea what the correct answer is. The Aurelia proves that the ones putting on this act know a lot about espresso machine design; but they consider this stuff as trade secrets, not as scientific or engineering knowledge that needs to be publicly reviewed.

My guess is that Schomer got the "you're a child" treatment too on his Italian Journey, and has been making it up ever since. The difference is that he's publishing, and we're testing and discussing. So eventually we'll figure it out.

I tend to get analytical with numbers, so one last post on the Elektra temperature test, then I promise I'll stop.

I redid the data so the X-axis shows shot volume, rather than time. This allows the 22 and 32 second shots to be shown in the same scale. I also added an average shot line (thick black) so one can tell how variable the shots are:



As one can see, the peak temperature at roughly 25m/L has a respectable 1C dispersion. But the shots rise and fall at variable rates, so the dispersion increases to a rather shoddy 2C to 2.5C at the shots' beginnings and ends. This remains true even if one removes the three outlier shots (3, 7, & 9)

This machine will never be be particularly temperature stable, although I'll experiment with different boiler levels and pstat settings (there'll be no modding on this baby)

My guess is that one can read what will happen to ristrettos, singles and ristretto singles simply by cutting off the graph at a lower volume, and assuming the temperature be the remaining curve stretched over the time of the shot:
-- A ristretto will be 40-45 mL (15 in the puck, 25-30 in the glass) and show mostly rising temperatures with slight drop at the end.
-- A single at 32.5 mL (25 in the glass, 7.5 in the puck) will mostly climb and level off at the end of the shot.
-- A ristretto single at 20mL (12.5 in the glass, 7.5 in the puck) will have a purely rising temperature curve.

The ristretto singles from these machines are perhaps the best shots, certainly the softest and butteriest, I've ever had. Yet I've previously gone on record saying that a rising profile cannot be good, since the low temperature will accentuate the sours at the start, the high temperatures the bitters at the end.

This machine is very confusing.

akin wrote:Hi Jim,

although the profile may be different for these - can anyone suggest how I can block half a hole on my fake scace basket

one or more single tiny copperwires in an electric cable do the trick for me. Just put it through the hole and bend it.
Hope it helps ...
Akin

Dankeschoen. I'll try it and be the second person with a ristretto thermo-filter.