Brew Pressure on Vibration Pump Espresso Machines

[@arisafghanzada6417]

This is honestly a really great espresso brewing / espresso machine technical tutorial. Props for creating content that advances the espresso communities knowledge and counters false assumptions.

[@Wholelattelovepage]

Hey a, thanks for the comment! Lot's more like this by manufacturer and model in our support center: support.wholelattelove.com/

[@Sunshrine2]

Finally, someone explained it and showed experiments behind their hypothesis. Yes.

[@Wholelattelovepage]

Hi AZ, Thanks for the commenty!

[@justinbouchard]

Absolutely fantastic video. I have no idea why the youtube algorithm didn't push this one out for you but it deserves 10x the views it has at least.

[@Wholelattelovepage]

Wow, thank you!

[@whitegianlu]

That's why my lelit anna comes with the opv setted up at 10.5 bars! Thanks Marc!

[@Wholelattelovepage]

You're welcome!

[@Joh146]

Many thanks, that were obviously the right answers to some questions which lead to hot discussions without having the facts.

[@Wholelattelovepage]

Hey Joh, You're welcome - Thanks for the comment! Marc

[@classicrockonly]

This makes me appreciate my Flair 58 a lot

[@SydneyPanda2016]

Thanks for so many wonderful videos. Great presentation and content. Learned heaps.

[@Wholelattelovepage]

Our pleasure!

[@rodrigodepazos3771]

Just the explanation that I needed!! Thanks a lot

[@Wholelattelovepage]

Glad to hear that!

[@mohmmedahmed8022]

Great video. Should I set appartamento to 10 bars to give me 9 bars

[@Wholelattelovepage]

Hi MA, Yes, a hair over 10 static gets you 9 on the puck. Marc

[@nelsondelatorre7381]

Marc, great video. I recently bought a RS Pro X from WLL and it came with 9 bars at the machine gauge. I’ve been chatting with Todd at WLL to help me adjust it up. Your Pro X review video shows that 10.5 bars at the gauge equates to 9 bars static pressure at the group head, so it sounds like it needs to be adjusted.

[@Wholelattelovepage]

Hi Nelson, Thanks for the comment and your patronage. Todd is a great resource! I agree you could adjust the pressure up to 10 - 10.5 bar static on the machine gauge. I would not get too wrapped up in brew pressure. So long as it's not crazy low or high and you're within a couple bars of 9 you're likely to notice little difference in your extractions. Lots of caveats to that statement like lighter roasts tend to extract better at lower flow rates and darker roasts tend to be better at higher flow rates. There's no magic to a perfect 9 bar in the portafilter. Marc

[@MrArdytube]

Another Excellent video….. Rancillio also suggests the pressure can be adjusted on the regular Silvia by measuring how much water the opv breads off in 30 seconds

[@Wholelattelovepage]

Hi Ardy, Thanks for the comment and adding that info! Marc

[@erlynlopez9731]

Excellent video Marc.. you have helped me understand how my machine works..keep it up...

[@Wholelattelovepage]

Hi Erlyn, Will do and thanks for the comment! Marc

[@knipsi22]

Have you testet a Gaggia Classic with the scace? I wonder if the popular 9Bar spring mod is needed or even accurate

[@m4cu53r]

Also would like to see the data

[@timgerber5563]

Thanks for clearing this up! I always wondered if we the 9 bars for espresso referred to a blind filter reading or are meant to be achieved during an actual extraction where pressure must be lower due to water being able to escape the system. The only other thing I am now interested in is to see what the group mounted gauges read during actual espresso extraction. Would have been nice if you had included this as well. Since espresso flow is not static like in a scace device this would be quite interesting.

[@Wholelattelovepage]

Hi Tim, You are welcome and thanks for the comment! Actually, when using a Scace you are not measuring static pressure as the device simulates an extraction by releasing water. Group gauges typically read about 1 bar higher than Scace pressure reading during testing. Marc

[@timgerber5563]

@@Wholelattelovepage Thanks for clarifying. What I meant with static is that flow doesn not vary with a scace device like it does in espresso extraction. It is just fixed, right? So if we know that group pressure is typically 1 bar higher than that shown by the scace device, how does group pressure look like in an actual extraction after you have adjusted it according to the scace device? I would assume that initially it builds up and then should drop as more coffee is extracted and flow increases. So what is the proxy pressure you guys set your machines to before shipping or when servicing?

[@Wholelattelovepage]

@@timgerber5563 Hey Tim, Group pressure typically does drop slightly as an extraction progresses. Depends on the grind as to how much. When we adjust pressure it's to 10 bar static for vibration pump machines.

[@chadajacobs]

@@Wholelattelovepage Technically, the gauges are all measuring static pressure (vs velocity pressure or total pressure), but the control volume is static, which I understand is what you are referring to when you state static pressure. The reason the Scace device is more accurate for actual brewing is, as you state in your video, it allows water to escape at an approximate rate of a puck of coffee (assuming your shot flows at the rate the Scace device is calibrated for.) If your shot flows faster, it will have less pressure, and vice versa. I believe these pumps are positive displacement and thus pump a constant volume. The pressure they develop is solely the result of the resistance to flow (coffee puck, Scace orifice, OPV). As for the video, I think you are spot on in helping us all understand the nuance of the pressure in an espresso machine, my only correction is to the way you use static pressure. Thanks for the video.

[@leomenashe6492]

Thanks for the great video! I wanted to voice one more supporting vote to request that you run the same tests for brew pressure on a BZ13, either in a video like this or just publish the results on the Whole Latte Love support page for that machine. Thank you!

[@Wholelattelovepage]

Hi Leo, Thanks for the vote! I'll do my best to make that happen. Marc

[@leomenashe6492]

@@Wholelattelovepage Great, thanks Marc!

[@krzysztofm.5639]

@@WholelattelovepageHi, did you make that happen? Where can I see the results? Many thanks in advance!

[@masicher1703]

Excellent Video. I replaced my faulty pressurestat a month ago, opting for the same black one. My thermometer that displays a temperature exceeding 112 degrees on the brew group. I have lowered the pressure to 0.8, which has caused the brew temperature to reach 95 degrees. Could I elevate the pressure to .9 or 1 while ensuring that the brew temperatures remain between 90-95? Your suggestion would be greatly appreciated.

[@Wholelattelovepage]

Hi M, You did not mention what type of machine. I'm assuming it's an HX boiler with E61 group. .8 bar in the boiler gives you an in boiler temp of ~117C. That temperature is reduced a bit in the HX section of the boiler due to the thermosiphon loop which circulates water out to the group and back. 1 bar in the boiler results in an in boiler temp of ~120C. Every HX machine is a little different in the offset between the in boiler temp and the temp delivered to the group head. Machines controlled by pressurestat tend to have a wider temperature range than those controlled by PID. Also this type of machine will overheat if left on and idle for long periods. Normal operating procedure of an HX pressurestat machine is to do a cooling flush from the group head prior to pulling an extraction. It flushes out overheated water and reduces brew temps. Generally you'd flush until water flow from the group is no longer extra steamy and turbulent due to flash boiling. It's usually a 2 - 6 second flush to reduce temps but depends on when machine was last used and how long it's been idle. Hope that helps!

[@masicher1703]

Thank you for replay. I'm sorry for not mentioning earlier, but the machine I have is the Rocket Appartemento. The temperature of 117C excessively high; nevertheless, your recommendation is to promptly power off the machine after every use if I'm correct?. Furthermore, I am considering seeking a method to autonomously control the heater by utilizing a sensor and electronic mechanisms.

[@JordanGonzalez1996]

Will you be doing a similar video for rotary pump machines? I have a pro 700!

[@hubbyofmad5122]

Yes please MARK

[@Wholelattelovepage]

Hi JG, Thanks for the request. I will visit rotary pumps in a future video! Until then, know that rotary pumps run much with less of change in pressure between machine gauge and what's on the coffee. That's due to the higher volume of wter they move at a given pressure as compared to vibration pump machines. Unencumbered rotary pump machines moves about 11g/s of water through the group. For vibration pumps it's 7-8g/s. Marc

[@djmatush]

@@Wholelattelovepage Good to know but anyway - waiting for rotary pump video. Cheerz Marc ( I have Quick Mill Aquilla Black ☕️)

[@telurkucing5006]

Nice video, now I know the reason to use my machine over 10 bar in my pressure gauge because before this video came in I always confuse about this

[@Wholelattelovepage]

Glad I could help!

[@MichaelBxl]

Great to know. Thank you. But the question is also to know if the "rule" of 9 bar pressure was meant 9 bar on the puck, or somewhere else...

[@Wholelattelovepage]

Hi MB, Thanks for the question.10 bar static pressure on the gauge of a vibration pump usually gets you ~9 bar max available on the puck during an extraction. That "rule" is overrated! It's become the dogma because that's what the original machines did way back when. I've had excellent shots pulled on manual lever machine that hit much higher pressures. And wonderful shots extracted at lower pressures. The only way to truly know (and honestly you shouldn't worry about it that much) is a group mounted pressure gauge or Scace or similar group pressure measuring device which can be tuned to simulate the release of water you'd have during a standard espresso extraction.

[@elisabethkiesel4567]

Thanks Marc, what about the Bezzera 10…..it’s a pain to adjust. My pressure when I use a blind basket is around 10.

[@Wholelattelovepage]

Hi EK, You're welcome! I have not tested the BZ10 but I did test a Bezzera Unica. For the Unica, a static pressure of 11 bar on the machine gauge results in ~9 bar on the coffee during an extraction. I'm not 100% certain but guessing it would be similar on the BZ10 or potentially a little bit higher with more plumbing between the gauge and group. Marc

[@vitorzanella]

Hi, Marc! Since you also sell the Lelit line and have access to the Scace device, could you tell us what static pressure value the Lelit Elizabeth manometer will show when adjusting the OPV to reach 9 bar of pressure in the group head using the Scace?

[@mikebarnes7734]

How is the pump/brew pressure adjusted on the La Nueva? Era Cuadra v1 espresso machine? It seems that the earlier machines were set for 16 bars, whereas the v2 appears to have a 9- bar setting!

[@Wholelattelovepage]

Hi mb, Unfortunately I'm not familiar with that machine. If it uses a vibration pump like machine in this video then you be looking for an OPV: Over Pressure Valve to adjust. If a powered by a rotary pump then there usually a bypass scree on the side of the pump to adjust the maximum static brew pressure.

[@dimvos]

Hi Whole Latte Love! I am trying to figure out what the right pressure during a blind shot should be on a Breville Dual Boiler. I don't own a Scace device or a portafilter pressure gauge. Thanks for a useful video!

[@Wholelattelovepage]

Hi DV, You are welcome for the video. When running a blind shot - so pump running but flow from the group blocked I'd look for 10-11 bar on the gauge. That should get you about 9 bar actual on the puck during an extraction. Marc

[@FatNorthernBigot]

Thank you. This was a no-nonsense answer, and there are precious few of those on coffee forums. 😁 I've just ordered a static pressure gauge to add to the bottom of my Rancillio Silvia's portafilter. Should I be looking for around 10 bars of static pressure, to achieve the optimal 9 bars when brewing?

[@Wholelattelovepage]

Hi AB, You are welcome and thank you for the kind comment. Yes 10 bar static should get you about 9 when actually pulling a shot - assuming grind is dialed in properly. Marc

[@FatNorthernBigot]

@@Wholelattelovepage Thanks for that. Subscribed.

[@uffa00001]

I bought a portafilter with pressure gauge and measured the static pressure of my 2001 Baby Gaggia, it was 14 (fourteen) bars. That's strange because my Baby Gaggia was not sold with a pressurized filter, yet Gaggia decided that it had to set the pressure to a pressure that would imply use with a pressurized filter. I will try to fix it.

[@chulolo997]

Hello Marc, would you know by any chance what the brew pressure of a Rocket Appartamento is when the brew pressure gauge (or static pressure) reads 12 bar?

[@Wholelattelovepage]

hi c, As I recall it's a drop of 1-1.5bar from reading on machine pressure gauge. Marc

[@chulolo997]

@@Wholelattelovepage thanks so much for the quick response!

[@warp2600]

That was very informative. Thanks.

[@Wholelattelovepage]

Very welcome

[@gavincansfield]

Hi Marc - you mention the static pressure to get 9 bars on the Scase [not sure if I spelt that correctly] on all the machines except the Rocket. What would you suggest for static if I fitted a pressure gauge to the group head? Jan23

[@Wholelattelovepage]

Hi Gavin, thanks for the question. For a static pressure gauge at the group head I recommend setting pressure to produce 10 bar on the gauge. No worries on spelling! It's spelled Scace. Marc

[@gavincansfield]

Thanks Marc - love the videos and thank you for responding so quickly 😊

[@andersrisager6518]

Great video! I'm curious: how would you go about adjusting towards 6 bars? On the Rancilio machine would this be as simple as setting the static reading to 9 bars or should you account for a lower difference between flow and static readings when lowering the overall pressure? Im trying to set my machine to 6 bars based on the ulka-pump flow chart but guess a static reading from manometer would be easy and way more precise. The question remains: how to convert static readings to actual pressure during shots with 6 bars of pressure?

[@Wholelattelovepage]

Hi ander, thanks for the comment and question. Unfortunately not as simple as setting to 9 bar static. To be precise you'll need a device like a Scace which can measure pressure in the portafilter as some brew water is released which simulates an extraction. However Scace and similar are relatively expensive. If you can measure static pressure in the group, ~8 bar there should get you ~6 during an extraction.

[@valfanculo4614]

Nice video explaining the bar pressure differences - would you know or can you tell me if - on my Bezzera Unica - it shows 12 bar all the time when i pull a shot - would you know if it does give 9 bar when the water hits the coffee at the group head or - have you tested this machine model to know what it actually does - as you showed the Silva hits 12 Bar like mines but is actually 9 bar at the group - have you tested the Unica this way - would you be able to test it and confirm what it does etc, thanks

[@Wholelattelovepage]

Hi v, have not put a scace with pressure reading device to determine group pressure during simulated extraction. My guess is it's significantly lower than 12.

[@valfanculo4614]

@@Wholelattelovepage i have added one that shows the pressure at the group head - it shows 11 bar on my unica - 12 bar on the machine - i am not worried about this 9 bar etc, debate - my only reason is being that my Unica has a whistle most times - due to the OPV - i have contacted Bezzera - they told me to contact you WLL for updates - they may release a new OPV or solution to it - how long do i wait before asking WLL about this - thanks - Machine is great - not a problem - 12 bar is fine for me - its the whistle that happens at most times -

[@valfanculo4614]

@@Wholelattelovepage i can show you a pic of it showing 11 bar - not sure how to add a picture here if you can - if you want to see it - where can i send it - thanks

[@ciprianfrasinescu]

Can you please make a video with the best built in fully automatic espresso machines?

[@Wholelattelovepage]

Hi C-A F, Here is a video featuring our 5 favorite super autos of 2021: kzbin.info/www/bejne/a6elZ5aqoqt9kLM Marc

[@ciprianfrasinescu]

@@Wholelattelovepage Thank you, Marc. This video is for countertop super autos. Do you have a video for built in super autos?

[@jpquiros58]

Gracias por esa informacion, tengo una Rancilio Epoca y quisiera saber cuanta agua debe de salir de la ducha y en cuanto tiempo para saber si esta dentro del rango normal, muchas gracias

[@Wholelattelovepage]

Translation: Thanks for that information, I have a Rancilio Epoca and I would like to know how much water should come out of the shower and in how long to know if it is within the normal range, thank you very much. Gracias por la pregunta. En general, las máquinas con una bomba de vibración funcionan con un caudal libre de 7-8 gramos por segundo. Las máquinas de bomba rotatoria funcionan a unos 10 gramos por segundo. Marc Thanks for the question. In general machines with a vibration pump run at an unencumbered flow rate of 7-8 grams per second. Rotary pump machines run at about 10 grams per second.

[@dakeepsgoing]

Just wondered if you had tested the pressure on the pump gauge to produce 9 bar on the portafilter for Profitec Pro 600?

[@Wholelattelovepage]

Hi DA, Yes, we set the OPV on Profitec machines with vibration pumps like the Pro 600 to produce 10 bar on the machine gauge when running the pump with blind filter basket inserted. Maarc

[@SK-su6xk]

Nowhere can I find a video or any other manual on how to adjust the pressure on Bellezza Valentina v2? Thanks for any help!

[@Wholelattelovepage]

Hi SK, It can be difficult to find info including diagrams for made in China products. You will likely need to open up the machine and find the expansion valve aka OPV. I do not have a Valentina to guide you but near 100% certain it is a vibration pump machine so once you find the OPV process is similar to what's shown in this video. I did locate this thread on Home Barista which may be helpful: www.home-barista.com/espresso-machines/valentina-brew-pressure-adjustment-t263.html

[@murphyrp01]

Why isn’t my ECM coffee machine not showing any pressure changes during extraction or when using the blind filter. This has worked fine before and coffee making still seems fine. Any suggestions

[@Wholelattelovepage]

Hi rp, Hard to be certain from here but sounds like the gauge is malfunctioning if machine is otherwise working normally. If you purchased machine from us and would like assitance you can submit a ticket to our tech support staff here: www.wholelattelove.com/pages/contact-us

[@gibson60]

Hey Mark. Thanks for this professional video!! Any idea why does the Apartamento comes stock with 12 bar static pressure ? One more question - if I brew coffee and have pressure gauge installed on the e61 brew head - should it still show 10 bars in case I want 9 bar extraction? Or is that just for static pressure ?

[@Wholelattelovepage]

Hey g, you are welcome for video! Machine manufacturers often set higher static pressures on vibration pump machines as they have lower flow rates than rotary pump machines. Also, the pressure is typically measured deep in the machine in cold water just after the pump. Static pressure at that point will in most cases be higher than a static pressure measured at the group. Don't get too wrapped up in a bar or two of pressure regardless of where it's measured. That said if looking to get 9 bar on your coffee during an extraction you'll need a higher static pressure like 10 bar on a group gauge to get it. Marc

[@carloslaboy32]

On a single boiler Rancilio Silvia, what should be the pressure gauge reading? 10 or 12 bars? 🤔 TIA! 🙌🏻

[@Wholelattelovepage]

Hi CL, Set to a static pressure of 10 bar if using a portafilter mounted pressure gauge.

[@w.p.6948]

i just had my bezzera bz13 professionally repaired, but now the pressure is set at about 8 bars (with blind basket, during coffee extraction it starts at about 8 and drops to about 7.2). im now struggling to dial in the espresso (which i usually know how to do), its always way too sour no matter how i adjust grind size and dose. could that be a result of the low brew pressure, aka do i need to adjust it?

[@Wholelattelovepage]

Hey wp, 8 bar static pressure (blind basket) is a bit low for a vibration pump machine. Actual pressure in filter basket is likely ~7bar during extraction if reading 8 on the gauge. +/- 2 bar off 9 has been show to have liitle affect on measurable espresso parameters like TDS. But, yours is near the point where flavor changes could happen due to pressure. What was your static pressure before service? If better results with that I'd open it up and adjust the OPV to static pressure you had before service. Hope that helps!

[@miguelcorreia7034]

In the appartamento how much pressure should we see at the group gauge to have 9bars at the puck ?

[@Wholelattelovepage]

Hi Miguel, A hair over 10 bar on the group gauge measured static gets you 9 on the puck when extracting. Marc

[@brewpilot8958]

Do you have a chart for all the machines you sell? I have a pathfinder and trying to figure out if 10 static is 9?

[@Wholelattelovepage]

Hi bp, we do not have a chart with all machines and there is some variance. On the Pathfinder which uses a vibration pump 10 bar static should get you a max of ~9 at the group during an extraction.

[@brewpilot8958]

@@Wholelattelovepage my pathfinder shows 10 bar at gauge and 11 at group head, strange.

[@mz67]

Hey Marc thank you for this helpful video! I was wondering about bz10 it would be great if you can help me out about the right static bar on the bz10 since it's 12bar factory set.. Lots of people change it to 10bar with blind basket. There are lots of threads and confusion about bezzeras default static bar pressure some say 12 is right some say change it to 10... It would be great if you test bezzera machines with that special portafilter 😊 thanks!

[@Wholelattelovepage]

Hi Mr Za, You are welcome for the video! What's right is hard to say. As I mentioned in this video manufacturers may have reasons for setting pressures higher than 9 bar static. It may be because of lower flow rates from vibration pumps as compared to commercial rotary pumps, the difference between what one sees as a static reading on a machine gauge vs. what the pressure is in the group during an extraction, etc. Many in the espresso community take 9 bar as an unbreakable rule. Turns out the 9 bar gospel may originate from the first pumps Achille Gaggia put in machines more than 50 years ago. I did not test a BZ10 when making this video. I did test a Bezzera Unica. It was set to 12 bar static pressure which produce 10.3 bar in the portafilter during a Scace test. The Rancilio Silvia Pro in this video shows a static pressure of 12 bar on the machine gauge and the same 12 bar on a static portafilter gauge. At that setting it produced a Scace reading of 9 bar while showing the same 12 bar on the machine gauge. Based on my test of the Unica if you want 9 bar on the coffee during an extraction I'd set static pressure on the machine gauge to 11 bar. That could be off as a Unica is not a BZ10. My recommendation however is to not worry so much about pressure. Personally I believe flow rate is more important than pressure. Try this... Dial in a coffee and extract it with the machine set to 12 bar static. Then keep all other variables the same, change the pressure to 10 bar static and extract. Do a blind taste test and stick with what you like. Marc

[@mz67]

@@WholelattelovepageHey Marc! What a helpful informations! i really appreciate your help and support :) there's no doubt that your suggestion is the best option. i definitely try it. Again huge thanks !

[@dabanbio]

i have elba mini presure about 12 bar its normal or not ?

[@Wholelattelovepage]

Hi d, some manufacturers set static brew system pressure higher than others - especially on machines with vibration pumps which have lower flow rates of brew water compared to machines with rotary pumps. 12 bar is common and I've seen that on machines from Bezzera and Rancilio. Keep in mind that brew system pressure is measured near the pump it will be higher than what is actually applied to the coffee. Also, that's a static pressure which is always higher than what's in the portafilter during an extraction.

[@stevenshen1994]

Hi Marc, my Lelit Kate comes with 11 bar on machine gauge. Should I just leave it or lower it to 10 ish? Thanks.

[@Wholelattelovepage]

Hi s, Thanks for the question. If that's a static pressure reading I'd leave as is. The 11 bar static on the gauge is likely producing ~9bar inside the portafilter during an actual extraction. Marc

[@xenon9887]

Thanks so much for the info! Would it be too must to ask to for a built in brew pressure gauge value for 9 bar on the coffee for the Profitec Pro 400? Would it be roughly the same as the 500, ie around 10.5 Bar? Thanks again!

[@Wholelattelovepage]

Hi x, You are welcome! To produce 9 bar in the group during an extraction we set vibration pump machines like the 400 and 500 to about 10bar when measuring static pressure on a machine's gauge.

[@arokglez]

What static pressure do you suggest for Breville Barista Express?, I still getting channeling because of the pressure.... If I grind coarser to get a pressure, the flow is faster and If I grind finer to get an ideal flow, the pressure goes up to the sky and I cannot control, both of this shots tastes awful.... I'm want to be able to slow the pressure to control the flow more consistent without have to grind more coarser... That you for the info... I learned something new and important today...

[@Wholelattelovepage]

Hi AG, Machines which come with a pressurized portafilter (Breville calls it Dual Wall) often run at higher pressure to accommodate brewing with a pressurized basket. To the best of my knowledge I do not believe brew pressure is user adjustable ob the Barista Express. You may need to compromise with a slightly coarser grind if worried about the pressure being too high.

[@arokglez]

@@Wholelattelovepage yes, is not factory user adjustable, but, by internal dimmer mod we could trick the pump controlling the entering voltages producing less pressure, and we could adjust using this method... Or not? I never ever use pressurized basket, always non pressurized. Thank you for reply :)

[@ultraman1017]

what about BZ13? 11 or 12 bar on machine gauge to achieve 9 at group?

[@Wholelattelovepage]

Hi Steve, Thanks for the question. Yes, I'd set ~11bar on machine gauge.

[@rafaelrgbarrocas]

Really nice explanation! What is the pressure measured in a portafilter gauge I have to set up in the profitec pro 300 to deliver 9 bars? The same of profitec in the video 10.5?

[@Wholelattelovepage]

Hi RGB, Measured using a portafilter gauge I'd go with 10 bar for 9 bar during extraction. Marc

[@צביאלבןדוד]

Hi! What do you recommend for crem one hx? The machine came with 12 bar on machine gage, I dropped it to 10. Is that right for 9bar in actual group?

[@Wholelattelovepage]

Hi user, I recommend setting to 10 bar static pressure.

[@adityahr1039]

Halo marc apa ada perbedaan antara tekanan termoblock dengan boiler??semisal kita adjust opv tentu akan merubah maupun kalibrasi grindsize gilingan kopi bukan??thks

[@Wholelattelovepage]

Termoblok digunakan untuk memanaskan air pada mesin berbiaya lebih rendah sehingga tidak ada hubungannya dengan tekanan boiler. Jika Anda menyesuaikan OPV, Anda mengubah tekanan maksimum yang dapat diterapkan pada kopi bubuk. Mengubah tekanan minuman mungkin memerlukan perubahan ukuran gilingan. Marc translation: Hello Marc, is there a difference between thermoblock and boiler pressure? For example, if we adjust the OPV, of course it will change and calibrate the grind size of the coffee grinder, right? Thks Thermoblocks are used to heat water in lower cost machines so has nothing to do boiler pressure. If you adjust the OPV you are changing the maximum pressure which can be applied to the ground coffee. Changing brew pressure may require change to grind size. Marc

[@redbirdx4]

Hey Mark, I have an Expobar Brewtus III double boiler machine. When looking at the machine gauge during the extraction of an actual espresso shot. Which would NOT be Static. It should be between 10.5 and 12 bars also? Same as your static tests. To get a proper 9 bar extraction at the portafilter? If I understand correctly.

[@Wholelattelovepage]

Hi PC, Thanks for the question. Been awhile since I've seen a Brewtus III. I have not tested that machine with a Scace so cannot say with 100% certainty. But if Vibration pump I'd try setting at 10.5 bar static. If rotary try 9.5 static.

[@redbirdx4]

@@Wholelattelovepage I'll give it a try. Thanks Mark!

[@CommentTaire]

Questions here: So most motorized coffee machines show the static pressure rather than the pressure on coffee? Static pressure is always higher than the pressure on coffee? My LaPavoni (lever, esperto abile) has a gauge right above the group head... I'm reading the pressure on the coffee, right? So if I'm reading 8 bars on that gauge, is this equivalent to 8 bars displayed on the gauge of a Rocket (or other comparable machine), or not?

[@Wholelattelovepage]

Hi CT, Static pressure is measured when there is no flow from the group - like if a backflush disc is installed in the portafilter. Most machine face mounted gauges measure pressure before the boiler (in cold water) and very near the pump. During an extraction those gauges do give an idea of pressure on the coffee but it's not as accurate as a group mounted gauge within the flow of brew water. It varies by machine and pump type but face mounted gauges may read a bar or 2 higher than actual pressure on the coffee during an extraction.

[@juiceodeagles5005]

Hi Mark, Is the 10 bar pressure from the portafilter gauge also for 9 bars on the normal rancilio silvia or just the pro? Also with my portafilter gauge is it best to use it with the basket in or out? Can't find the answer to this anywhere. Thanks!

[@Wholelattelovepage]

Hi JODE, Both the Silvia and Silvia Pro use similar if not identical pumps so chances are yes 10 bar static on a PF gauge will get you ~9 bar during an extraction with properly dialed in grind size. Basket in or out makes no difference. I do suggest cleaning the group head of any residual coffee debri prior to using a PF mounted gauge. Hope that helps! Marc

[@rayfoster8198]

Nicely done Excellentl info Thank you

[@Wholelattelovepage]

Glad you enjoyed it!

[@sport016]

I see a lot of machines and it describes 20 bars is it true? because I thought most bars were better

[@Wholelattelovepage]

Hi s, A lot of lower end machines advertise 15 bar etc. It's all marketing based on the more is better mentality. Technically pumps may be able to produce 15 bar but you really do not want to extract espresso at that pressure.

[@davidtaylor6124]

Very interesting, thank you! I can't even drink a shot of espresso without milk so I'm guessing these things are not hugely going to change the taste I perceive but I'll adjust my GCP to 10 bar on the static PF gauge and see what happens :)

[@Wholelattelovepage]

Hey David, You're welcome!

[@damienhull6497]

Thanks for this. There seems to be more than a little confusion about this topic. I'm finding it tricky to get good shots out of my BZ13 at higher pressures. Channeling becomes a big issue. In the process of testing things. I think I've got a bit of work ahead of me.

[@Wholelattelovepage]

Hey DH, You're very welcome! Good luck with your testing! Marc

[@davelasker]

I understand why the pump pressure gauge reads higher than the Scace. But why does the group pressure gauge read higher than the Scace? What causes the drop in pressure between the group and the Scace? Thanks for an informative video!

[@Wholelattelovepage]

Hi Dave, You're welcome! The group gauge is further back in the system. Not a lot further but enough it holds at a higher pressure than what's read within the portafilter where water is exiting. Marc

[@checkwhatsleft4565]

The pressure reading on the Scace higher than the group gauge was due to Scace emulates the espresso extraction, water goes through and you get the lower pressure reading as well, essentially we need 9bar limited at the coffee puck not the pipe line.

[@ficokan]

@@Wholelattelovepage hello hello, can you please please write if you know how much pressure is lost between group head measurement and Scace. For example if you install group head pressure gauge and do real extraction and it shows 9bar, what will than show Scace, 8-8.5? I just need that info to complete this puzzle of pump pressure 🙂 thanks a lot

[@Hildichimo]

Great video, this is something I've wondered about for a while. It would be great if you could test a bezzera crema/bz13 in the same way given people tend to talk about how high the opv is set on them from factory

[@Wholelattelovepage]

Great suggestion!

[@pavlo-slava-ukraini]

Please do! And BZ10 as well. Thank you!

[@supercres]

Pesado TPD- temperature and pressure device. 354 AUD, 400 including the Pesado portafilter ($258, $291 US respectively).

[@Wholelattelovepage]

Hi PC, Thanks for the info! Marc

[@Mustapha_El_Hamdaoui]

Has anyone played with Lelit Bianca V3 OPV?

[@Wholelattelovepage]

Yes we have! www.wholelattelove.com/products/lelit-bianca-v3-dual-boiler-espresso-machine-matte-black?variant=40644730224694

[@Sharingsummer1]

I have profitec pro600, I set my pump pressure at 9 bar, but with blind disc installed it reads 10bar from group head pressure. Why group head is showing 1 bar higher than pump guage? It happens either with blind disc in or espresso extraction. It always reads 1 bar higher from group head gauge. My machine was just arrived from WLL about a week ago. Is it defect or faulty? As on other videos from WLL for these same machines, it should read same pressure when back flusing using blind disc? Please advise.

[@Wholelattelovepage]

Hi Sharing, Your machine is not defective. Perfectly normal that pressure reads a bit higher on the group gauge. Here's a video explaining why: kzbin.info/www/bejne/aHLViHSqqrqHha8si=RK-ZouF6r1PcNljq The video demonstrates on a Pro 700 but reasons are the same.

[@Sharingsummer1]

But why the machines here in this video is reading same pressure?? Dont understand why.. see 3:36 1:01

[@Sharingsummer1]

Please advise!

[@bmfailing]

Wouldn't a group gauge measurement while extracting be an even better way to measure the pressure on the coffee? Why resort to static measurements if the machine has a group gauge?

[@Wholelattelovepage]

Hi BF, Yes, you can for sure use a group gauge. Static pressure measurements give you a read of the maximum possible pressure (minus the losses in machine plumbing) the machine can apply to the coffee. Pressure on the group gauge during an extraction can be different depending on grind size of the coffee. Marc

[@pavlo-slava-ukraini]

Thanks a lot Marc for a so much needed explanation. As you see the Bezzera users are the most confused. If you would be able to make a good overview of the pressure settings and the outcomes, it would solve the whole Bezzera mystery. Thanks in advance!

[@Wholelattelovepage]

Hey PM, Outcomes depend on the type of coffee used and subjective personal flavor preferences. I recommend leaving the machine at factory pressure setting. But, no reason you can't adjust and taste the results. Marc

[@slowbot68]

could have confirmed whether to adjust clockwise or anti...

[@Wholelattelovepage]

Hi slow, on most all OPV's it's clockwise to increase the pressure.

[@michaelchung2956]

DIFFERENCE BETWEEN FLOW CONTROL AND OPV? }

[@Wholelattelovepage]

Hi MC, Flow control controls the flow rate of brew water. OPV controls maximum pressure of brew water. Marc

[@Serrajimed]

Bonjour Marc Très bon sujet je vous remercie pour votre engagement. J'ai une question quelle pompe vibrante ou rotative privilégier vous l'expert pour équiper votre machine sans prendre en considération le paramétre bruit ??

[@paul10021999]

La pompe rotative monte plus vite en pression, elle permet par exemple de mieux gérer une préinfusion, est "beaucoup "plus stable et enfin elle permet d'etre raccordé au réseau d'eau mais elle est aussi plus chère...

[@Wholelattelovepage]

good morning Marc Very good topic, thank you for your commitment. I have a question which vibrating or rotary pump do you the expert prefer to equip your machine without taking into account the noise parameter. Comme le mentionne @pinard Fr, la pression monte plus rapidement avec une pompe rotative et la plupart des machines à pompe rotative peuvent être connectées à l'alimentation en eau domestique. Les pompes rotatives ont un débit d'eau libre plus élevé d'environ 11 grammes par seconde. La vibration de la pompe est d'environ 8 grammes par seconde. Étant donné le choix, je préfère une pompe rotative pour la possibilité de se connecter à la conduite d'eau, un débit plus élevé et un son plus agréable. J'espère que ça t'as aidé! Marc As @pinard Fr mentions the pressure rises faster with a rotary pump and most rotary pump machines can be connected to household water supply. Rotary pumps have a higher unencumbered water flow rate of about 11 grams per second. Vibration pump is about 8 grams per second. Given the choice I prefer a rotary pump for the ability to connect to waterline, higher flow rate and more pleasant sound. Hope that Helps! Marc

[@manxman8008]

What about flow rate? It's not measured by the machine

[@Wholelattelovepage]

Hi m, Thanks for the question. Flow rate is not measured unless machine has a flow meter. Flow and pressure while not the same are "cousins" with higher pressures resulting in higher flow rates. Marc

[@MJ-nb1qn]

Isn’t it really about the grind and tamp, but more important The TASTE! BTW as machinist I can make a copy of the Scace for peanuts.

[@Wholelattelovepage]

Hi MJ, Thanks for the comment. It's always about the taste in the end! Marc

[@davidtaylor6124]

I was thinking the same thing until I read the linked interview with Scace. There's more to it than just making a few bits. My immediate question was how big is the hole that lets the water out to simulate the extraction flow rate? In the interview he also says he uses a plastic 'fake puck'. Then there is the problem of getting a temperature sensor quick and accurate enough. I'm a software developer & amateur machinist so I have some of the skill necessary to build and run one, but I don't have the metrology that Greg has! Making an adjustable OPV and static pressure tester is no great challenge, but I think one of these is a bit of a mission and without the metrology expertise would probably just be misleading.

[@uffa00001]

"as machinist I can make a copy of the Scace for peanuts" Man, I think you have an eBay business waiting for you. I certainly would be a buyer at a decent price.

[@Wyman642]

I adjusted my Appartamento’s pressure down a bit because it was 13 from the factory measured at the grouphead. But I only lowered it to 11.5. Honestly, that works just fine with a good grinder. It extracts the right amount in the 28-sec range and the coffee comes out perfect. So maybe 9 bar is not always necessary?

[@Wholelattelovepage]

Hi S, Thanks for sharing. As mentioned in the video manufacturers have their reasons for setting pressures as they do. Personally I believe flow rates are more important than brewing pressure and in our testing as well as others there seems to be little difference in extraction yields through a surprisingly wide range of brew pressures. Marc

[@gavincansfield]

Hi Marc - you mention the static pressure to get 9 bars on the Scase [not sure if I spelt that correctly] on all the machines except the Rocket. What would you suggest for static if I fitted a pressure gauge to the group head? Jan23

[@sdm107]

Wow that rancilio is huge

[@Wholelattelovepage]

Hi s, Well, it's the only dual boiler in the group here so a little more room under the hood is needed! Marc

[@daniwello]

My Lelit Anita produces great-tasting coffee with nice flow rate but the gauge shows 12 BAR, is that OK?

[@Wholelattelovepage]

Hi d, Honestly people get too wrapped up in brew pressure. Many manufacturers use a higher static pressure setting in machines with vibration pumps as they move less water than rotary pumps. Understand that the pressure reading is taken deeper in the machine near the pump in the cold water before the boiler and does not represent perfectly represent the pressure in the portafilter during an extraction. 12 bar should be fine on your machine.

[@daniwello]

@@Wholelattelovepage thank you so much for the detailed reply! So, no need to Adjust the OPV the 9 bar read at the gauge? Thanks!

[@Wholelattelovepage]

@@daniwello I'd leave as is.

[@ecsekiandras]

Okay, as far as I understand: barista tries to build up the pressure with proper puck prep and using a decent basket depending on the dose. OPV lowers the pressure by leading the extra water back to the tank. The lower the setting is, the more water is released. Now how does OPV help the barista to pull a better shot? It approaches the pressure level from the opposite direction. If i'm not wrong, this leads to a longer brew time and nothing more. I'd set the grinder coarser a bit in the first place instead of adjusting the safety instruments of the machine

[@Finnspin_unicycles]

Yes, your grind size and puck prep are how you "normally" dial in the extraction time. But the pump in most machines is capable of producing more pressure than you would want, some issues that you may have for example is channeling if the pressure and flow is too high, or in general not being able to find a grindsize that produces good extraction times while not being too fine. The OPV's main function is not safety, it is exactly meant to set brew pressure.

[@j0.ZEF-Who]

MARK you funny man . that Rancilo looking seXy - Gotta update my Carrezza soon

[@Wholelattelovepage]

Hey J, Well, I try every once in awhile. A Pro X would be a sick upgrade! Marc

[@samuelsaraiva8153]

Loveeeee cofffe

[@elmariachi451]

Been toying with this topic the past few days. I had the Magica with Flow Control set to 12 and thought the flow was too fast. I set it to 10 and it felt really good pulling shots. With FC I was even able to get amazing results. Even saw at one point that Bezzera made a kit that would put the machines at 9 bar. For the time being I'll leave it.

[@Wholelattelovepage]

Hi AG, thanks for sharing!

[@After_GF]

Hi Mark My machine doesn't have a internal gauge so I was setting my machine at 10 bar with portafilter gauge, closed system Coffee and especially light roast coffee was awful Until I found out that my machine needs 12 bar pressure to have 9 at flow

[@Wholelattelovepage]

There ya go! Marc

[@Aa-ron01]

I've been thinking about this for the last two months using my stock gaggia classic, it feels awfully familiar to the full size two group machine we used to use when I was a barista. I must measure it with a flow restrictor if possible to see actual brew temps like, I'm barely pressing in my pucks before the opv just opens and I'm not using crazy fine grinds either, the coffee just about produces small clumps during grinding so it's right where it should be. I'm not convinced the opv mod is right way to go, I think I'll be going dimmer mod with pressure gauge.

[@sdm107]

James Hoffman seemed confused by this

[@davidk7262]

Hoffman knows a lot about coffee, roasting and commercial machines but his domestic machine reviews were very poorly researched. He just clearly didn't understand the machines or how to use them.

[@Wholelattelovepage]

We have our specialties. I'm lucky with nearly instant access to most every prosumer level espresso machine available in North America. Marc

[@damienhull6497]

@@davidk7262 You might be on to something. I've got my BZ13 at 9 bar on the gage cause Hoffmann recommended this. Testing to see if I can get a good shot. I will say that high pressures lead to channeling. At least in my experience. Maybe I need to work on puck prep. In any case, I have work todo.

[@rustycolon9368]

@@damienhull6497 Did you solve this or dial back the pressure? I'm very interested in this machine, but I'm really frustrated that there's no information available on this and many many people seem to complain about the factory pressure set too high...

[@3ede467]

The problem is, that this video is misleading and confusing as hell. There is no way to calibrate a machine to a "true" dynamic brewing pressure of 9 bar, not even with a Scace device. Which coffee puck does that device even resemble? A 16g or a 22g puck? A finer or a coarser grind setting? Setting the static pressure higher than 9 bars means that in the worst case a finely ground high dose will be extracted with more than 9 bars. Calibrating the static pressure on a closed system means calibrating the maximum pressure which shouldn't get higher than 9 bar in the portafilter, even if no water is released.

[@Trevtardius]

I really disagree with the “don’t adjust the brew pressure” comment! I had really big issues with channeling and uneven shots on my Rocket Appartamento. Bought an e61 pressure gauge and it read almost 15bars! Now adjusted to about 8,5 and I get consistent and good shots with almost no channeling… the best upgrade I ever did, along with getting a wdt tool. (I was using wdt before adjusting the brew pressure)

[@Wholelattelovepage]

Hi IT, Thanks for sharing your thoughts. Marc

[@JusBThankful]

All

[@crazydubwise]

What?

[@3ede467]

I wanted to lower the pressure on my machine to 6.5 bar and was researching on how to do that. So I stumbled upon this video and it confused me as hell. After all my research I can say that this video is misleading and I wanted to correct the mistakes that it makes: 1. Dynamic pressure can be measured but it cannot be calibrated as it is dynamic as the name says. 2. The Scace thermofilter device that they use to calibrate the machines cannot resemble a generic resistance that can be applied to all pucks. It just resembles the resistance of one specific puck. Using it to calibrate the machine can in the worst case result in higher pressure than expected and wanted. A coarsely ground 16g puck for example has far less resistance than a finely ground 22g puck. Which flow rate does the scace device resemble? It cannot resemble both and therefore cannot be used to calibrate brew pressure. 3. The static pressure is the maximum pressure that a machine can produce. You want this to be calibrated to 9 bar (or whatever brew pressure you'd like) as you don't want your machine to be able to go higher than that. 4. Using a gauge on a closed portafilter doesn’t mean that the system is closed, as the OPV releases water and overpreassure. You want to calibrate that threshold. So here is how you adjust your brew pressure: Get yourself a pressure gauge that can be mounted to your portafilter. Let the system heat up. Measure the static pressure that is built up in the portafilter and adjust it to your desired pressure. Enjoy the results!

[@Wholelattelovepage]

Hey Chris, Thanks for adding your thoughts. I wish you were more specific about what you feel is misleading. I have to mention if what you want is say 9 bar on your coffee inside the PF during an extraction that's not what you will get if you set to 9 bar static pressure. Also mention it seems a lot of folks get a little to obsessive with brew pressure. I get comments all the time from people worrying about not being at exactly 9 bar. Nothing magical happens at 9 bar. Just happened to be the pressure in machines (who knows where that was measured) from many years ago so it's been the espresso dogma since.

[@3ede467]

@@Wholelattelovepage Hi there! I'll try to be a bit more specific… When I mount a pressure testing gauge onto my portafilter (unscrew the spout, then mount the gauge), tighten it and start the pump, it will show the static pressure inside the portafilter, right? As no water can escape the portafilter in that scenario, the pump will go up to maximum pressure and the OPV will regulate that it does not exceed that specific maximum pressure by releasing water out of the system. The mounted pressure gauge on the portafilter will now show the maximum pressure that is build up in the portafilter and that could get built up during an extraction. Let’s say I want to calibrate that static maximum pressure to 7 bar (don’t get me wrong, I don’t care about 9 bar being set), so what I am going to do now is changing the OPV setting until my pressure gauge on the portafilter shows 7 bar. What I find misleading is - if I understood you correctly - that you say that I don't get true 7 bar in my portafilter with that setting as I need to use a Scace device for calibration instead. The misleading thing here is, that a Scace device relases water at a specific flow rate that cannot be used as a generic rate value as every puck has its own flow rate depending on the dose, the coarseness of the grinds, etc. which results in a different resistance from puck to puck and which also results in a different brew pressure from puck to puck. Therefore it is impossible to set the brew pressure to exactly 7 (or 9) bar as every puck releases its own specific amount of water. But what you most likely want is to limit the pressure that can be build up to your desired brew pressure to make sure it won’t be exceeded during extraction. I know that 9 bar of static pressure will supposably not result in a dynamic brewing pressure of 9 bar as long as the flow rate allows the machine to run on less pressure. But that is totally fine and nothing bad. The bad thing would be if I‘d choose a finer grind size for a ristretto and my machine would go up to 10 or 11 bar as the resistance increases because of the finer grinds. Hope that this clarifies my thoughts…