I have been toyeing with the idea of a "semi-pro" espresso machine for a long time. Previously I owned a small, the simplest KRUPS machine ever. Then, for the ease of use (so that parents can use it) I bought a Delonghi Magnifico 3000 automatic. And I have been constantly in search of a good deal for a better, more professional semiautomatic.

I was planning to learn the craft on it, and then maybe open a small coffee shop that would be aimed on the quality aspect of the coffee. Use the machine there (at the beginning the volume of visitors will be small, I predict). Then I would see how the things would evolve, and get a two-group LaMarzocco GB5.

With all this in mind, I acquired a used Promac Club PU 1-group, semiautomatic-in a good shape, after a year of usage, with approximately 3000 shots pulled.



It is a 4-liter, one-boiler machine, http://www.promacitalia.com/schede/green_club_eng.pdf (pdf, 545 kB). I have thoroughly cleaned the group head, changed the screen (was filthy you could not believe that water was still flowing through it), rubber gasket, cleaned steam wand, portafilters, backflushed it several times with Cafiza2 in course of two days-to really clean the baby up. Changed the chemicals in the de-calcifier.

I have noticed that the previous owner had a coffee-spillage inside the machine, on the metal panel near the front (missed the boiler, luckily). So I will have to clean it more inside. (yes, you guessed right, I am a cleaning freak when it comes to coffee)



Having no prior first-hand experience (only tons of reading and watching videos), I have spent the last few days trying to pull shots, get the right combination of grinds coarsness, learning to steam milk (using a soap in a water technique), and generally getting to know the machine and finding out what I might need. So far I see a need for a pressure-meter, termomether, good tamper, ridgeless double basket. Right now I have no idea what the pressure and temperature are, the boiler pressure shows 1.3 bar (19 psi). Also, I am not yet familiar with the insides and will need further reasearch before I begin substantial tweaking. I know only where: the temperature adjustments are made (black plastic box), and the pump pressure adjustment screw.

Right now, I think, the boiler pressure is too big. Or is it not? I might need to reduce it to 1,1 bar (can't microfoam milk-gets hot in like 12 seconds (0,3 liters volume of milk in a 0,75 liter pitcher), and the microfoam is only on the top, milk gains only 15% of volume by frothing). Are my assumptions on the too-high-boiler-pressure correct, or the problem is in my technique of frothing (inexperience)?

I will get back to this thread and post more observations and questions. Thank you for looking, and your ideas.

Fantastic first post! And welcome.

You're going to enjoy the step up to a more serious machine. Just to get it out of the way, there's a question to ask up front -

"what grinder are you using with the machine?" (Oh, and what beans?)

Also - I'm not familiar with the Promac - you say it's 4l, one boiler. Does that mean it's a one boiler, dual use machine? Or (I'd assume) a heat exchanger? Ah - I assume the boiler pressures you quote mean it's a HX

Steaming small volumes with a big machine is difficult - i'm finding it a steep learning curve, as everything happens quickly. Apart from technique, 2 things to think about are boiler pressure, but also the level of water in the boiler. (adjusting this will make your steam 'wet' or 'dry').

Good luck! I'm sure there'll be some more qualified posters along in a minute...

Thank you for the encouragement and warm words

triptogenetica wrote:"what grinder are you using with the machine?" (Oh, and what beans?)

I have Mazzer Mini Man, cleaned and with burrs "as they were new" (Mazzer technician's remark made a week ago). As a coffee I am using Brasilia Santos, roasted 3 months back... yes, I know. But for learning, I think it would suffice, and anyway, I want to finish it, so it does not sit on my shelf anymore.

triptogenetica wrote:Also - I'm not familiar with the Promac - you say it's 4l, one boiler. Does that mean it's a one boiler, dual use machine? Or (I'd assume) a heat exchanger? Ah - I assume the boiler pressures you quote mean it's a HX

I guess it is HX (I am not yet sure of the terminology and technology). I have been beefing up on espresso making technique up until several days ago, so I will have to catch up in the machines' inner parts, tweaking etc. In the other post (Calibrating the brew temperature of a commercial HX espresso machine) I have come upon a picture, and I think it is the boiler and group that are on the machine I own.


EDIT: I found another useful pic on buying advice for a used Rancilio S26 (http://www.partsguru.com/RancilioEspressoMachines.html)

triptogenetica wrote:Steaming small volumes with a big machine is difficult - i'm finding it a steep learning curve, as everything happens quickly. Apart from technique, 2 things to think about are boiler pressure, but also the level of water in the boiler. (adjusting this will make your steam 'wet' or 'dry').

I agree, I find it very difficult to do in such a short time. What I do with the steam now is this:
1) open the steam fully (without the wand being in the pitcher)-it lets out a burst of water for a second, then it is a wet steam for another second.
2) when the steam gets dry (almost invisible after 2-3 seconds) I close it and put the wand in the pitcher
3) open the steam again and froth away.

Good on you.

You will want to descale the machine I would imagine. I'm sure you'll find heaps of info on that if you search for it on this site.

Regarding the milk, it will most likely be lack of experience. Again, a good search on this site should yield results. For large boilers, depending on steam tip, I have found that centering the tip in the middle of the jug a centimeter or so below the surface is a good place to start. Turn on the steam, make a small 'tearing' sound with the steam tip close to the surface for a couple of seconds, then submerge it a little more so that it just rolls the milk. Ends up as a standing wave rolling in on itself. Hold it until its a little too hot to touch and stop. Mentally rehearse what to do and where your hands will go, as it happens quickly.

Read up on dosing, distribution and tamping.

And MAKE SURE YOU HAVE FRESH BEANS.

Good luck.

Your machine looks A LOT like a Rancilio S26 or EPOCA S1; almost identical components. This piece of info should help you since there are some discussions here and elsewhere on these machines.

With the above assumption, your machine holds ~100ml in the HX. I can't tell from your photos if you have a thermosyphon or not but I'd guess not based on what's visible from the photos. Your machine might(or not) have a flow reducer in the GH. Do one thing, measure how much water you get in 10secs (with no PF in the group) to verify. If you have one (a jet) your life should be much easier.

You got yourself a workhorse, no question about that. I'm guessing your steam tip has 3 or 4 holes. For easy steaming for smaller amounts of milk, you need to reduce this number to 2 holes. You either close the extra ones on your current tip or buy one with 2 holes.

Now, on brew temp and p-stat setting, your machine will tend to have a very cool GH temp and that will be a challenge for someone new to the machine. What I suggest you start with (till you get a feel for how this thing is different from other machines you read about) is the following: 1. set your p-stat to activate the element on 0.8bar (it should stop @ 0.95-1.0bar). 2. You need a way to get your GH up to brew temp at the start of a brew session, I suggest a few (3-4) back flushes. 3. flush till the boiling stops (you need fast hands as the rotary on this machine will get you from boiling to cold water too quickly). 4. Lock in your (already prepared PF) and brew.

This should get you started on reasonable grounds till you get a feel for this thing and come up with your own techniques/mods/prayers .

Congratulations on your new toy, welcome to the club, and all the best shots .

gyro wrote:You will want to descale the machine I would imagine. I'm sure you'll find heaps of info on that if you search for it on this site.

I have had a technician have a look at a boiler, and he said it was pretty clean. But thank you for the suggestion, I will think about it later on.

gyro wrote:Regarding the milk, it will most likely be lack of experience. Again, a good search on this site should yield results. For large boilers, depending on steam tip, I have found that centering the tip in the middle of the jug a centimeter or so below the surface is a good place to start.

I have a three-hole steam wand. Will try to post a picture later. As for the technique, that is exactly how I do it. I also have a pitcher in the freezer, and milk is ice-cold-to gain more time for frothing.

gyro wrote:Read up on dosing, distribution and tamping. And MAKE SURE YOU HAVE FRESH BEANS. Good luck.

I have been practicing dosing, distribution and tamping a lot. Read almost everything about it. The pity is that a new basket and tamper will arrive some time next week, so I am stuck with a ridged basket and a flat-bottomed glass as a tamper (yes, I am paying attention not to break it). Understanding that I do not have the ideal instruments nor coffee for tinkering with espresso extraction (now it is dark, runny, almost without crema, bitter)-I am focusing more on getting to know the insides of the machine, and on frothing the milk. And thank you for the wishes.

Lowering the boiler pressure.
I have turned the Parker thermostat (? I am still unsure what is what) clockwise one full turn, and got the pressure in the boiler from 1,3 to 1,1 bar. I think it could be enough tinkering with the boiler pressure for starters.

Promac is Rancilio's "second brand". What you've got is an S26 in a cheaper skin, the internals are all Rancilio and parts supply is easy.

Alan

coffee.me wrote:With the above assumption, your machine holds ~100ml in the HX. I can't tell from your photos if you have a thermosyphone or not but I'd guess not based on what's visible from the photos. Your machine might(or not) have a flow reducer in the GH. Do one thing, measure how much water you get in 10secs (with no PF in the group) to verify. If you have one (a jet) your life should be much easier.

First of all, thank you for the wealth of information, now I will have something to process I did the measurements you suggested, and they are as follows:
1st run after machine sits for 15 minuts: 80 ml
2nd run 2 minutes after the first one: 80 ml
What does it say?

coffee.me wrote:I'm guessing your steam tip has 3 or 4 holes. For easy steaming for smaller amounts of milk, you need to reduce this number to 2 holes. You either close the extra ones on your current tip or buy one with 2 holes.

The steam wand has 3 holes. 1 hole too many that it is, for smaller quantities. I think I should somehow, upon your suggestion, close (non-permanently) one of the orifices. Any ideas? (EDIT: a toothpick?)

coffee.me wrote:1. set your p-stat to activate the element on 0.8bar (it should stop @ 0.95-1.0bar).
2. You need a way to get your GH up to brew temp at the start of a brew session, I suggest a few (3-4) back flushes.
3. flush till the boiling stops (you need fast hands as the rotary on this machine will get you from boiling to cold water too quickly).
4. Lock in your (already prepared PF) and brew.

1. I am afraid I do not know where is a p-stat (pressure stat?) and how I can adjust it with such a precision. And what element should be activated, heating? After the handle on the manometer shows 0,8 bar? Now it goes to 1,1 bar and stops there. Is that by turning that Parker knob I posted before?
2. no problems with understanding that
3. boilng stops? how do I know it has stopped? what would give it away, the sound in the boiler?
4. understood.

coffee.me, thank you for such valuable information, it will cut my learning time considerably.

Alan Frew, I am happy you too confirmed it. I was not sure what machine (insides) did I get and where to find info on that-google did not show much at all. Now I will look into Rancilio S26, and apply the tweaks and knowledge-base on my machine.

Three-hole steam-wand tip, macro photo. The inner diameter of the tip is 1 cm.



And also I attach a photo of the machines' insides. Thanks to coffee.me for identifying the parts.