[movedhere] Brewing Equipment (non-machine specific) [move by] Mal.
Well the BZ35 i purchased second hand on the for sale forum has arrived, i spent this morning plumbing it in and then fired it up.
looks quite at home beside the La San Marco grinder, a little bit heath robinson with the drain hose for the moment and had to block it up a little due to not having quite the right fittings for the water inlet.
had a problem with the pressure regulation on the boiler, but i seem to have repaired it and am just tuming it in.
will post with more details as i get familiar with it and get some good brews happening.
the first few coffees have been reasonable, good crema and ok flavour - it seems to be a very forgiving machine.
[movedhere] Brewing Equipment (non-machine specific) [move by] Mal.
starting to get the bezerra tuned in, coffees this morning were pretty damn good.
i have slowly been raising the boiler pressure and waiting to see if i have problems with the PRV lifting again.
is it satisfactory to set the PCV to just below the point where the PRV lifts or should i install a pressure gauge on the boiler?
Why do you want to raise the boiler pressure? I have the BZ-40 and the gauges are very handy when youre adjusting the machine but after that not really required. If you could get a gauge to temporarily install it would take a lot of guess work out of what youre doing. My pressure relief valve is set at 1.5 Bar and at that setting its screwed right down against a spacing washer. I run the boiler around 1.1 Bar. Our machines are very similar in construction, the -35 is slightly smaller and obviously doesnt have the gauges.
because, as i said, the PRV was lifting - so presumably the PCV was set at above 1.5 Bar, when i had rebuilt it and refitted it i started with the adjustment wound right out and i have been slowly screwing it in to increase the operating pressure - and making sure the PRV doesnt lift again.
I can get a pressure gauge from work and fit it to the boiler, would it be better to get a PF with a gauge and set it that way?
different pressures you would be measuring. boiler around 1.3 bar, group around 9 bar.
Sorry youve completely lost me with what youre trying to achieve. Brewing pressure and boiler pressure are completely different and independent variables. Sorry if this is telling you how to suck eggs, but Im not sure what youre referring to by PCV?Originally Posted by 3B3D3029313D255C0 link=1231921987/4#4 date=1232026927
You set your boiler pressure by a pressurestat, and that should be around 1.0-1.3 Bar depending on your choice. Ive found my boiler OPV was screwed all the way in at 1.5 Bar relief. The OPV is a safety valve that does not open in normal use (the Bezzera incorporates an anti-vacuum valve in the same OPV, however thats obviously closed in operation)
The brew pressure is set by the adjustment screw on the procon pump, and that is obviously set around 9 Bar give or take, your choice. The brew water OPV is set at 10 Bar and is not user adjustable. Again its a safety valve that opens when the water in the HX expands when the machine is idling.
If you have access to a PF with gauge then yes use that to adjust the brew pressure. Adjusting the boiler pressure and checking the setting of the boilers OPV will be difficult to set exactly unless you can modify a pressure gauge to fit on one of the boilers fittings for testing.
Hope that helps.
thanks peter, yes i realised i am confusing myself with thinking the boiler pressure is directly related to the brew pressure.
to use the same terms as you, the OPV was lifting and releasing pressure when the machine was on, so i stripped and repaired the pressurestat (the adjuster screw had a damaged head and was wound right in and seized), now I am attempting to adjust the pressurestat to the correct point, i have been slowly increasing it a quarter of a turn at a time and waiting to check the OPV doesnt lift again.
My intention was that once it lifted the OPV to then back of the pressurestat half a turn or so.
here is a photo of the current result,
...and here is the pour....
looks good there matey
Hi, I think that is probably a pretty dangerous way to do it. I wouldnt be adjusting the pressurestat without knowing the actual pressure. your boiler pressure release could be set really high for all you know. Id for sure connect up a gauge to read boiler pressure if you can.
Yeah Im with Damian on this one, I think Id want a gauge on there. Adjusting the boiler pressure affects the brew temperature, not pressure, so you may be able to get some idea by letting the machine idle for a while until the HX water has fully equalised with the boiler pressure, then hitting your brew button and seeing how active the water is when it comes out. If it spurts and slutters like crazy for a full 60-70 ml then its too hot, no spluttering at all and its probably not hot enough. However thats a seriously rough way to guess and would be no way to set the OPV. Keep in mind this is a safety device youre adjusting and the power of steam has to be seen to be believed if something lets go. Alternatively an infrared thermometer on the lower half of the boiler MAY give an indication (boiler pressure and temperature are directly related and can be converted) but of course I dont know if you have access to one? Just the same, I dont know, its all a bit dodgy in my mind and I seriously think getting hold of a gauge will be your best bet. Just think of how much money youve saved by overhauling it yourself *;)
BTW when you stripped the pressurestat did you fit an overhaul kit in it? Very cheap, easy to install and basically essential unless the PS was basically brand new. Available from Coffeeparts
Edit: I just re-read your post and saw how you intend setting the OPV (half a turn over operating pressure). You may find thats too close. The pressurestats are supposed to be accurate, but theyre not. Youd probably find having the boilers OPV set so close to operating pressure would have it releasing all the time and will both drive you nuts (mine leaked for a while and that was bad enough) and is probably not good for its seal. Theyre supposed to remain closed in normal operation and just get tested periodically by pulling on the stem with a pair of pliers
Edit#2 I just tried an infrared thermometer on my boiler and wasnt able to get any sort of consistent reading off it for some reason. Not sure quite why, but it was a dodgy way to set pressure anyway, so maybe it was trying to tell me something ;D
ok, well the boiler looks to have a blank plug on an outlet, so i can probably fit a pressure gauge on that, as per your detailed post i dont think i am far off the mark anyway - firstly it makes a pretty damn fine espresso, secondly there is only spluttering for a little bit and then running nice and evenly.
As far as setting the OPV I couldnt suggest relying too much on the espresso quality as an indication of where youre at with boiler pressure. To give you an indication, the difference between a boiler gauge pressure of 1.0 Bar and 1.5 Bar is a temperature difference of only 7 degrees. By the time thats converted to a temperature at the heat exchanger, THEN a temperature at the puck, how long you flush, etc etc I think you can see it will make very little difference.
By all means, once youve got the machine set up and youre used to it then you may want to play with your boiler pressure to tweak it, but thats a whole different era to overhauling and setting the OPV. At the moment this is the coarse adjustments, and the tweaking is later by taste. The pressurestat screws do need to be turned quite a bit to adjust however, so you may well have it pretty much right, but without a gauge its just guessing.
If the blank plug doesnt work, the other one you could try would be the steam outlet as thats just a hole in the top of the boiler.
get the pressure gauge from work and set it to 1-1.3 bar, lower side preferred
you could have spent all this wasted time sipping on beautiful ristrettos
hard to tell from the pics, but the final product of your shot looks a little light. also, a good indicator of the shot being built correctly is a nice mousetail pour, without too much erratic behaviour, i guess you want the espresso to pour out like its just falling off the end of the spout.
bean quality and age
all play their role (some to greater extents than others)
I thought the colour looked better at the start, but it seems to be going a bit quick and turned very pale.
thanks kindly for all the comments,
firstly i have found a pressure gauge so i will fit that to the boiler and set as adviced at 1-1.3 Bar.
i agree the pour shows signs of blonding towards the end of the shot, very early days though and i am carefully improving technique and make small changes to single elements of the process to move towards enlightenment!
back again! took me a while but i finally fitted a pressure gauge to the steam fitting for the milk, it was a little low, about 0.7bar i have set it at 1.0bar so i am happy with that for the time being.
otherwise its just practice & experimentation!
I too am doing up a BZ35e - looks very similar - and am at the stage of dismantling and descaling.
Has anyone here some experience taking the solenoid valves apart? People say unscrew a bolt, but mine have a clip-type arrangement on top - how does this come off?
Ive just asked the same question in another thread - then realized its a year old! Hope here is better.
you should be able to slide the clip off, then the coil should come off. Hoving said that, I have one like you describe which wont come off - they have stuck together over time, and wont come apart. Not a problem for me though, as I needed to replace the whole thing anyway due to a bad seal.
sorry, mine didnt require that sort of work so i dont have any experience with the solonoid valves!
Slide the clip off, the solenoid coil will slide off the shaft. The wet part of the solenoid can then be taken apart with 4 screws. I initially didnt do mine on overhaul which was a mistake as they were partially blocked. Very easy to take apart.
hi all, i have started to feel i am getting this machine dialled in! well, maybe its more a case of me getting dialled into the machine.
i have made a short and dirty video of a pour with the BZ35 if anyone cares to look and comment!
its hosted on vimeo,
i will do a better one when i can engage a professional camera person (wife)
Nice & very clean set up
Nice Bezzera BZ 35
Nice La San Marco grinder
Whats not to like about this set up
Ohh and the video was good are you related to Spielberg :o
Thanks for the compliments, its a while since i have had the camcorder out and i realised when i was editing that the shots of the pour were not what they might have been! also because sal was busy i had to shoot and pour hence there are a few gaps in the process!!
i would be interested in your experienced opinion of the pour - up until 2 weeks ago i had only ever made coffee in stovetops so i dont have the critical faculties to really judge what i am doing.
Tamping technique is good
If it was not you would be having gushers or squirts all over the place
However the puck could have had a little more pressure to slow down the pour to 25/30 seconds
As far a the naked pour goes it looks like your doing everything just fine
Remember the most critical measurement is the taste of the end product.
I know Ive got it right when the first piccolo latté lasts about 30 seconds and I find Im on my way back to the machine to make another!
i agree that is the critical criteria, its just that i find it difficult to have confidence in my assessment of the taste - it tastes so good i am buzzing on a caffine OD from tasting so many brews as i make minor adjustments!Originally Posted by 12273032023A2738343931550 link=1231921987/28#28 date=1233410504
That sounds like you are well and truly in the ballpark! *;D :D ;DOriginally Posted by 07010C150D0119600 link=1231921987/29#29 date=1233435709
thanks for the replies guys, Damian, Pete - good to know someones taken these valves apart before me, and its all worked out.
Works busy at the moment - Im away from home all week every week, and only home at weekends. :( But Ill get a chance to work on the machine sometime in the next 2-3 weeks, as my relaxing weekend task!
(Im taking it very slowly. Id rather do things slow, and get it right, than rush the wholething. I hope to insulate the boiler while Im in there, too)! :)
Then if I can get shots like those described here . . ;D