mmmmm.
I have a suspicion, and from what I have read on this site so far, the answer probably lies here
Yesterday my Vibiemme Domobar Super arrived in all its shiny glory. If you can remember back to your first machine, you'll know how good this particular gent is feeling right now. I have been lucky enough to pair it with a Mazzer Super Jolly, so now the journey can really begin. But back to the suspicion...
This is the second Vibiemme I have tried in New Zealand (the retailer was kind enough to lend me an older machine for a couple of weeks) and it is the second machine that has had the pressurestat set to 1.5 (if you believe the gauge of course, but as I have no other point of reference, it seems a fair enough tool at this stage).
I am a total beginner, but from what I am reading, 1.5 bar is going to be a tad hot. The cooling flush was spitting fire. The gauge also goes from green (traditionally good!) to red (traditionally not so good) at exactly 1.1 bar, which agrees with what I have found on this excellent forum, so this is where I have first set the pressurestat.

So do you think this a change made by the NZ importer, or do all VBMs arrive like this from the factory? The thing is, although the packaging had definitely been played with (missing straps etc), the boiler wasn't full, so they would have to fill, adjust the pressurestat to produce super hot water, drain and then send on to the retailer. Seems like a pointless, timewasting, stretch of the imagination. It would be good to get some feedback from other VBM Domobar owners to see if this drastic a setting change was needed.

Onwards then, to the OPV setting. The green = good, to red = bad transition on this gauge is at 8 bar. Having just read all about brew pressures here, and also Randy's super helpful manual (which Vibiemme now seem to be paraphrasing in their own manuals - which is sincere flattery indeed) it looks like I should be aiming for around 9 bar (according to taste, which may come later on) which would read about 10 bar on the gauge. At the moment, it can easily get above 12 on a blind flush. So again, we have a pretty sizable adjustment required from the setting the shiny beauty arrived with. And again this is consistent with the loan machine.

Has anyone else had a similar experience to this? It's an interesting start to what I hope to be a fascinating journey to espresso perfection. All comments appreciated.

Thanks too to Randy for that manual. Awesome stuff, and more useful detail than anyone could wish for, I am sure.

I've got a VBM Super HX which is about 2 yrs old now - i went through about 3 of them when i originally purchased mine (various reasons).

All of them came with the Pstat set to around 1.4-1.5 on the top end of the cycle - i've adjusted mine down to about 1.2 - which keep the very long cooling flushes down but still gives enough steam power.

The OPV's were all around 12-13 with the blind filter - i've adjusted mine down with the help of a pressure gauge to 9bar which shows on my gauge as 10 with a blind filter...

I believe they ship from the factory like this - my ones had definitely not been opened before and the importer verified that they don't do any bench testing or tweaks....

I love mine!

Excellent, thank-you for your reply. I am glad that this looks like being a standard setup from new (for the NZ market anyway), but it is also intriguing to say the least that the factory would ship their machines at such variance to the accepted norm of brewing techniques.
It makes me wonder how many people buy this machine and live with the bitter extraction that the factory settings would make hard to avoid?
Interesting. I'll be keen to see what effect lowering the OPV has on what I have seen so far.

deity6667 wrote:
All of them came with the Pstat set to around 1.4-1.5 on the top end of the cycle - i've adjusted mine down to about 1.2 - which keep the very long cooling flushes down but still gives enough steam power.

I am a little further on the journey now, and really keen to know how you find the recovery time at 1.2? That is where I set mine for a while, and with a short flush of about 5-8 seconds after a good warmup of 1.5+hours I get a wonderful looking first shot with the right kind of mottled appearance. Taste = super bitter, but I think this is more to do with early blonding. After that though, I am taking quite a bit of time to prepare the next shots, but they are all flat pale crema, like it isn't back up to temp yet.
I have cranked it back up to 1.5 so will try that for a while to compare, but would love to hear from you and any other Domobar Super drivers.

I'm the only coffee drinker in the house so i generally only make 1 espresso at a time - but when we have friends/family around i find that the recovery time is quick between shots and i normally do a quick cooling flush. I single dose so weigh before and after grinding and i weigh the extraction. Normally i'm aiming for around 80% for the coffees i like.

see Digital espresso or a way to consistency

Bitter for me is normally an under extraction - i would tighten the grind up a bit. What coffee are you using and how fresh?

How about a video post of the extraction and prep?

Many thanks for your help. Interesting about the rebound times. I wonder how accurate the gauges are? After returning to 1.5 I am now needing a longer cooling flush, but it seems to recover faster. The steam power has gone up a notch too. It sure is a powerful steamer.
You were dead right too. I tightened the grind and it made by far the best espresso to date. This small adjustment prolonged the extraction time before the onset of blonding and the result was in the same ballpark as the good shots I have had from decent cafes. Not as smooth and delicate as the best, but in the same flavour ballpark. Nice. This was my first milestone, so very happy. I'm amazed at how small a movement on the grind setting can make such a difference. A second shot confirmed the result though, with another milestone of the first flat white that passed the spouse test.
I have been using Weka coffee recently as they are local, well priced and seem to be very consistent. The beans are almost always roasted the day before, and I'll generally clear what I have within a fortnight.

The digital espresso is an interesting concept. It makes a lot of sense, and I can see how it would provide a more accurate target. The variation in crema does seem to be significant. If I can work on a better extraction from the clues I get from the bottomless portafilter, and combine this with an extraction ratio target, it looks like this could really speed up the learning curve. Time to buckle up and get extracting. The next target is consistency.

I'll see what I can do about a video. I am struggling with distribution in particular. I bought a doserless SJ from TradeMe and I think some people may enjoy seeing how far this thing can throw, no, fling clumps and grinds into and around the basket. So much for being a less messy option. I'll search to see if anyone else has had the same experience, but at this stage I am thinking of getting a doser unit and unwinding the conversion. Or work through the quirks, time will tell. If it was easy, it wouldn't be fun.

There is a "ton" of information available on the Vibiemme Domobar Super Hx model on this site, not the least of which would be the formal review of that model.

/vibiemme-d ... eview.html

Of importance would be the fact that US models are fitted with a thermosyphon restrictor of ~2.8 mm in the upper grouphead tube (at the hx end) which substantially reduces grouphead temperature and thus minimizes the flushing requirements. From your standpoint, it should be interesting to know whether or not this restrictor is available to the New Zealand market should you desire to fit same.

Thanks Eric,

I have spent many pleasurable hours browsing this site, but may be suffering from information overload. Recalling the more relevant snippets to the surprises found on this journey can be tricky to say the least.
This is at least the fourth time I have read the formal review, and it's interesting what you pick up each time around. A dose that doesn't touch the shower screen during the extraction...really? I thought to have covered the gamut of possibilities, but clearly not. The lower I dosed, the more got stuck to the screen. And more channeling issues to boot. 16 grams is the current favourite, but there is a long way to go. Too many unknown unknowns, to borrow a phrase.
Pretty confident at this stage that once some consistency is possible on the grind, temperature is my next target. And the thermosyphon will undoubtably play a part. Some searching required to see how I can tell. And why VBM would do this for the US and not other markets. If the result of no thermosyphon restrictor is longer flush times and quicker recovery, I can live with that.

erics wrote: Of importance would be the fact that US models are fitted with a thermosyphon restrictor of ~2.8 mm in the upper grouphead tube (at the hx end) which substantially reduces grouphead temperature and thus minimizes the flushing requirements. From your standpoint, it should be interesting to know whether or not this restrictor is available to the New Zealand market should you desire to fit same.

Mine has this installed from factory- cant tell you the size as I didn't measure it.

But they can be purchased here....http://www.espressocare.com/Qstore/Qsto ... Restrictor

TwoDoubles wrote:.The lower I dosed, the more got stuck to the screen. And more channeling issues to boot. 16 grams is the current favourite, but there is a long way to go. .

With the VBM DD (same portafilter and basket as the DS) I am dosing about 16.1-16.3 or so (still experimenting with extraction ratios with this machine).