Hello,

I just bought a manometer portafilter, which can measure pressure in the portafilter. I have already experience with the SCACE thermofilter, but I have the SCACE version without the pressure meter part. The manometer portafilter came in today but without any documentation. Below are some pictures taken with my iPhone and I hope someone could help me figure out how to measure the pressure correctly. The pressure is in BAR.

Another question is related to the Brewtus (Brewtus III). While pulling an espresso, the pressure will build up to approx. 11 bar according the the meter on the front of the Brewtus III. Isn't this a little too high? Shouldn't it be more in the neighborhood of 9 bar? Is there a way I can bring the pressure down? I am using the Brewtus III with vibration pump (so not the rotary edition).

sjjan wrote:Below are some pictures taken with my iPhone and I hope someone could help me figure out how to measure the pressure correctly. The pressure is in BAR.

Looks simple enough, have you tried locking it in? The second photo appears to show a hole drilled through the body to the gauge. The last photo appears to show an orifice that will allow flow during the shot (similar to the thermofilter).

Isn't this a little too high? Shouldn't it be more in the neighborhood of 9 bar? Is there a way I can bring the pressure down? I am using the Brewtus III with vibration pump (so not the rotary edition).

Yes, I recommend 9.5 bar as a starting point measured by the inboard gauge. The FAQs and Favorites links to threads explaining everything you need to know in the section entitled Vibratory pumps.


Expobar Brewtus OPV

Dan,

I read the info your wrote elsewhere on the site. I think I can find the OPV valve as I can just follow the water tube (not the inlet but the other one) back to the OPV. Then I can turn the OPV screw counter clock wise a little. Any idea how much?

I placed the manometer in the brewhead and simulated making an espresso shot. The pressure goes up about equal on the pressure meter now available on the Brewtus III as well as on the manometer at the end of the portafilter handle. However, no water flows through the valve at the bottom, so there is no water/shotflow like with the SCACE. Is there something I should adjust?

What would be your guess as to how far to adjust the OPV CCW? A quarter of a turn? I need to go from almost 12 bar to 9.5 bar.

I had some chat with the supplier of the manometer and he wrote that as is the manometer works as a device measuring the blind filter pressure (as if I were doing a blind filter action). There is no flow. Then I can also simulate a flow by taking off/out the rubber (black) something and it should simulate a flow.

Is the blind filter method OK and enough?

Or should I unscrew the whole bolt??

Then I have no pressure simulation as normally happens when extracting an espresso. I could also put in a basket (single/double) but to my understanding no coffee as it would disrupt/clog the valve channel (sorry if the English here is not perfect).

Sjoerd Jan

The Expobar's OPV is not a precision instrument; as I recall, 1/4 turn is around 1 bar. The onboard gauge will read slightly higher than actual brewhead pressure. If you adjust to 9.5 bar according to the onboard gauge, that's close enough to adjust by taste (low crema production, flat taste = raise pressure; high crema production, fussy extractions, sharp taste = lower pressure).

Pictures of the internals of the Expobar Brewtus III

I took some pictures of the internals of the Brewtus III since I would have to adjust the OPV anyways. I would not be able to recognize the difference between the Brewtus III and II internals but here they are:

Inlet tube (long one with the waterfilter at the end) coming from water reservoir
(I assume this is not the right tube for finding the OPV!!).


Top overview of the 2 boilers of the Brewtus III.


Overflow tube leading the the OPV
The transparent tube in the top back (which leads to the watertank and is the shorter of the 2 tubes or overflow tube) is split from one transparent tube by a splitter into two tubes which both are connected to the copper colour metal part. The blanc metal part with another transparent tube goes from this copper part and continues on to another part.






Where and what do I turn counter clockwise (CCW)?

Look for this:



It appears to be on the left (?), unfortunately with the nylon adjustment screw oriented towards the back of the machine's faceplate. The nylon adjustment screw should be facing upwards. Oh well, loosen its fittings, orient it properly, retighten them. Don't handle these fittings roughly, one-quarter turn past finger tight should seal.

Dan: there is indeed a copper coloured flat - (not +) screw there. See picture. I moved the tube where at the end you find the adjustment screw a little up, then I turned that adjustment screw a quarter CCW, then moved the tube where at the end you find this adjustment screw back to its original position. Right? or should you adjust at first more than 1/4th CCW like a whole turn orso?

How are "normal" consumers supposed to do this? I assume that lots of espresso machines are delivered to the homes and being not-adjusted they will never be able to pull that perfect espresso from it, right? How come they don't set the pressure to 9,5 in the factory? Its like buying a new car, but the ignition is not working right and not tuned (or something else). The car is new and everything works, but you need it to be tuned right for it to work.

sjjan wrote:How are "normal" consumers supposed to do this? I assume that lots of espresso machines are delivered to the homes and being not-adjusted they will never be able to pull that perfect espresso from it, right? How come they don't set the pressure to 9,5 in the factory?

Technically it doesn't matter what the OPV setting is if you're pulling doubles. But lots of people pull ristrettos or "accidental" ristrettos, so the OPV comes in handy. This is explained in I still don't get it: Why adjust the OPV? as are many other pump-related factoids at your fingertips from the FAQs and Favorites (hint, hint).

Anyway, back to your brew pressure adjustment. I'm not certain that's the OPV, but it's not rocket science. The diagram below shows how to find what-goes-where.

Dan: that is the right adjustable screw. In the Brewtus III it is not of white plastic anymore. Adjusting it CCW brings the pressure down. Thanks for the tips!

I have read through most of the FAQ posts on the vibration pump and OPV discussion and also noticed the diagram you posted of the machine and where to look for. However, it is still not clear to me what effect different coffee amounts (ristretto, espresso, doubles) would have on the pressure setting. If I use a naked portafilter, the pressure dail now shoots up to approx. 9.5 bar. If I make an espresso, the pressure goes to about the same 9.5 bar. If I use the manometer portafilter (as with a naked portafilter) I get on the dail of the Brewtus III 9.5 and on the manometer 9.0 bar (a little lower). That seems OK. Nothing here is calibrated, but indicative I believe.

Now why would they set the OPV at 11 bar at the factory? If a blind filter delivers about the same pressure as a single espresso, then I would believe a double espresso would be also at the same bar pressure?

Now when I make my espresso I get way more flavor. I was testing some espresso blend of Miscela d'Oro from Sicily. At first (with the higher pressure of more than 11 bar) it tasted dull, but now it is way better.

So, I am most likely not understanding why having the right OPV setting will not make much of a difference.

Thanks for all the help. It is here now almost half past 2 at night and my wife probably thinks I am completely mad with this coffee stuff staying up that late.

I read somewhere else that you might be updating the review of the Brewtus II to include Brewtus III info. If I can be of any help, let me know.

Sjoerd Jan