Dan said in his musings on the Elektra A3 "... even the commercial HXs are noticeably more "civilized" than their less pedigreed [read: prosumer] colleagues."http://www.home-barista.com/reviews/buyers-guide-to-elektra-a3-t7.html. Now, I've come across quite a few similar statements in the course of my "research" to the effect that commercial machines are more stable than prosumer ones, but haven't found much by way of substantiating evidence. Is there any?

Anyway, if we hold this to be true I wonder

1) Which are the decisive factors?
2) How could this influence/ help my buying decision?

1) As far as I can see, most prosumer machines discussed - and thus owned - by people on CG, a.c., German Kaffee-Board and here are a pretty homogenous lot: heat-exchangers with a thermosyphon-group (Bezzera's boiler-connected-to-group system forming the most substantial minority). On commercial machines, however, you find all sorts of proprietary systems (This is just "paper" knowledge, please do correct me, if I'm mistaken.). So what could be the unifying element here, providing improved stability? The use of rotary over vibe pumps doesn't do the trick, as Jim Schulman & Ken Fox found http://groups.google.de/group/alt.coffee/msg/2b47739bdaa2cd65?hl=de. Would it be bigger boilers, longer HX elements - any ideas? Or is it more a question of specific make rather than "pedigree"?

2) Now, while there are quite a few 1-group machines of commercial pedigree around, very few fit the restrictions of regular kitchen setups. Add to that, that some people aren't willing to have a 5+ liter boiler - be it for ecological, sanitary or economic reasons - that leaves you with only a handful of available models. Question is: Do these atypically small commercial models still retain the suggested temp stability advantage. If sheer size (of boiler, tubing, whatever) is the decisive factor, they wouldn't. So I could just as well get a, say, Butterfly instead of a Rancilio S26 (or I'd have to move and get a Classe 8 ).

The funny thing is, that for home machines with their typically intermittent use temp consistency would be much more important than for continuously used commercial models. In a nutshell - do smallish commercial machines put an end to complicated flushing rituals? (I hope I got my point across, sorry it took me so long .)

sheygetz

another_jim wrote:On older LMs after idle, it's basically impossible to do anything except dump the first two to three shots (or in a store, put them in lattes).

What do you mean by "older" in this case? Are you talking GS and older or are you talking early gen Linea? I've never worked on a GS in a commercial environment, but found that even the first gen Lineas required no more than an initial "warm up" flush.

I found that the Mia required far more water to be flushed through the group after the first shot or two than commercial HX machines I've worked on. With the commercial machines, I saw a similar initial "cool down" flush, but then when pulling consecutive shots it seemed far more stable.

In my opinion, commercial HX machines are much easier to manage than prosumer sized machines. Large boilers and HXs are more stable and require far less surfing than their smaller cousins.

My Faema E61 is fairly easy to manage after any idle time. The initial flush will bring temps down quickly, the following shot's temps will display a little more fluctuation than I care for, but after that the temps will remain stable and consistent until the machine is left idle again. The group will require a very brief flush (1-2 seconds) in between shots when used consistently. I rarely end up with more than one sink shot after idle time.

The A3 requires a bit more care after idle time. The initial flush seems to bring temps down just as quickly as the E61, but the the first two shots exhibit less stability. Perhaps this is due to the smaller boiler and HX requiring some time to stabilize. By shot three I can achieve the kind of stable temps that I am used to with the Faema. I am still fairly new to this machine, but as I use it more I am becoming more accustomed to its behavior and I seem to be able to get stable temps a bit sooner (not always).

I also spent about one year pulling shots with a Salvatore Famosa E61 (2ltr. boiler). It was harder to achieve stability with this smaller machine. It was very sensitive to initial flush times. Too little and the shot would overheat during the beginning of the extraction, too much and the temps would drop below the target temp, probably due to the HX needing to refill and heat up. It took me a bit of time to get a feel for this machine. Once I got used to its pace (too much idle time and you would have to carefully bring temps back down, not enough idle time and the machine would not get the recovery time that it required), I could usually achieve stable extractions by the second or third shot.

I will end by saying that I find big HX machines easier to use, but with a bit of practice smaller machines will get great results without too much waste (sink shots). Unfortunately for home baristas, the first couple of shots will almost always end up in the sink. Actually, this is not such a bad thing, since I think that it is a pretty good idea to season the group and PF before pulling shots.

That's odd. I've worked on those machines for years and didn't experience that. It might just have been due to the combination of garbage shots to season the clean group, a steady volume of business and a methodology that consisted of a quick flush both on removing the portafilter and right before reinserting it.

Thanks for your responses - I've read them with great interest and some confusion
I guess I've caused this myself when I used the phrases "Thermal stability" and "temp consistency" too vaguely. I was only thinking of the in-between-shots-stability, not even considering the during-shot-stability ( I guess that was too black-belt for me). So, there's actually two criteria. To put this differently:

*How much does any given machine overheat with, say, 30 to 60 minutes between shots?
*How much of a temperature loss occurs while the shot's being pulled?

(Is that about right, guys?)

To sum up the discussion so far: Jim says his Tea overheats a lot, but predictably so, while the Juniors he tried bandied about rather uncontrollably. So he would prefer the prosumer machine for typical home use. Dan otoh found specifically the Junior to need shorter flushes and be "less complicated". He assumes that sheer thermal mass is the key, a notion seconded by Ken. (Though AFAIK the Junior only has 2.5l boiler volume and is rather smallish. At least on paper that's not far from a Pulser or Butterfly, isn't it.)

So, it seems to me the jury's still out, right. If mass should be the key, then "small commercial models" (viz. Brasilia Portofino, Carimali Uno, Gaggia TS/TD) don't have much going for them wrt temp consistency.

sheygetz

sheygetz wrote:

*How much does any given machine overheat with, say, 30 to 60 minutes between shots?
*How much of a temperature loss occurs while the shot's being pulled?

(Is that about right, guys?)

actually, not all machines "overheat" during idle times.

i guess i would say you're looking at:
What is the range of brew temp (above and/or below brew temp as well as the total swing)
What is the range of in-brew temp

I revived this thread to see if there might be any additional comments at this point.

The reason it is on my mind is that I'm going to look at a Brasilia Portofino tomorrow, which would be quite a bit cheaper ( and a whole lot riskier ) than a Vetrano.

Anybody?

Just a thought . . . I am far less "into" this than many are, in that I love good espresso but don't delve into science as much as some do (perhaps as much as I should) . . . so I have little to contribute here other than an observation.

sheygetz wrote:Now, while there are quite a few 1-group machines of commercial pedigree around, very few fit the restrictions of regular kitchen setups. Add to that, that some people aren't willing to have a 5+ liter boiler

A 1-group Elektra A3/T1 has a 6.0L boiler, and there are a number of people here who use them. So, too, does a 1-group Faema Legend/Jubile. The 2-group versions of these machines have 9.0 and 11.0 liter boilers, respectively.

The 1-group Elektra A3/T1 runs at 2000 watts (110v*), while the 2-group is 3700 watts (220v). The 1-group Faema runs around 3500 watts (on 220v), while the 2-group is 4000 watts (220v).

Just in the FWIW Dept.

Cheers,
Jason

* Available in 220v also.

Different use cases, different priorities, different solutions.

Like saying, "would it be better to buy a used John Deere 1600 Turbo or a new John Deere X300 to mow my lawn?"

malachi wrote:Like saying, "would it be better to buy a used John Deere 1600 Turbo or a new John Deere X300 to mow my lawn?"

Or maybe, "would it be better to buy a used mazzer Super Jolly or a new Mazzer Mini to grind my beans?"