9 bar or 11 bar - What is the right pump pressure for the espresso machine ??

Luca Bezzera explains why small machines with vibration pump need 11 bar and the big rotaty pump is fine with 9 bar. Luca Bezzera erklärt, warum Espressomaschinen mit Vibrationspumpen bei 11 bar arbeiten und die Rotationspumpen lediglich 9 bar brauchen.

[@zhum1738]

This answers why my bezzera magica has 11 bars pump pressure. Thank you!

[@poppiesrule]

What an exciting opportunity to check out the Bezzera factory! I would love a tour of the facility and an explanation of what all the equipment we saw in this video is for. I noticed service panels at the back of the bench to power the different machines and a lot of gauges that can measure pressures at different points in the machines. I wonder where they check the pressures and what other equipment they have to calibrate and tune espresso machines. This is fascinating, good job!

[@elisha770]

very interesting video...loved the shop walls illustrations.. :)

[@TheEspressoTV]

oh yes this is typical mechanics wall paper .)))

[@tubeDaskal]

Wow I'm impressed! That's Italian and German bro science at it's best! 9 bar is 9 bar, 10 bar is 10 bar, 11 bar is 11 bar either it comes from a "professional" or a "toy" pump. But if Illy says 9+ bar then that must be correct. So to clear things up, the semi professional machines may have a group head valve before the portafilter which is a resistance valve with a little spring (maybe set at 2 bar) so if your OPV is set to 11 bar the actual pressure that lands on your portafilter is 9 bar. But if you have a solenoid valve like the "little David" has, you don't need that extra pressure.

[@TheEspressoTV]

Hi Dimitris, sorry for my late answer, I like your comments!! The best understanding is in flow dynamics, shown in Bernoulli (incompressible media, laminar flow). The get the same volume /time with identical tube diameter the pressure is lower if the volume is higher. In German it would be easier to explain.. The pressure difference can be calculated by Bernoulli, with a flow of 100l/h of rotary pump pressure is 9 bar, with a flow of 35l/h the pressure must be higher to acchieve the same flow...

[@chungteng1972]

TheEspressoTV Go Markus :-)

[@dominicschmidt1016]

Markus you make the mistake to conflate fluid velocity with flow rate (velocity times cross section of flow). If you still believe this after 4 years of putting this video up I challenge you to try it out and use the same portafilter, grind setting etc in two identical machines, one with vibratory and one with rotary pump (such as the one from Rocket) and show that extraction time is different at same pressure. Otherwise please remove this video as it is misleading to say the least. For the avoidance of doubt, pressure means pressure at the brew head.

[@mz67]

@@dominicschmidt1016 well idk what to say.... I'm just confused.... I read literally every comments here and in websites about this topic and still no straight and convincing answer... Honestly I'm just so sad I have bz10 and i set the opv on 9.5 bar and i do like my shots but I'm still sad because i still don't know 11bar is the right pressure on vib pumps or no... And i doubt about my shots which really annoys me! One more thing which made me completely disappointed and sad my bz10 factory set at 12bars and this video and machines 8 years ago were 11bar factory set... And they are same only buttons and lights changed in bz10.. What a mess! Help me if you know what's up with this topic. So sad.

[@roaddream5541]

@@mz67 Hi Rayan - as per my comment it is unfortunate that the video is still up as it is simply wrong. If it were true that Vib pumps need to be set to more pressure (everything else like for like) versus rotary pump then this would be quite commonly known. What matters is the pressure at the brew head and anything between 8 and 10 bar is OK and just means you need to adjust grind and dose. Tim Wendelboe brews at 8 bar for example - most people do 9 bar. I think factories changed bar setting at these machines to be more suitable for pressurised filter baskets. If you use a standard basket you want to be somewhere between 8-10ish. Just adjust the OPV once and it should stay good for years. Most important is that you like your shots! As long you do, no setting is "wrong". However the physics in this video is wrong!

[@gogo22976]

Vielen Dank - sehr interessant!

[@alexk0il]

Amazing auto-generated English captions. "also Jesus knowing Parkash wet season for husband when they have applied. Oh..." 😂

[@dimogrec]

very interesting thanks! by the way I love the "decoration" of bezzera factory ( 3:31 and 5:24 ) :)

[@RazvanPana]

Yes, it's true, I tested my home espresso and coffee from 9 bar is bad taste, as pressure increases is getting better and better. Thanks for the advice.

[@clint87ua]

Ich Kaffeemaschine mit einer Pumpe ULKA EP5, die bei 230V arbeitet, aber das Netzwerk immer 205-215V, Kann mein Gerät nicht, weil es Probleme mit Strom arbeiten?

[@spidiq8]

I get the smaller pump having to work harder to produce more flow. However, doesn't the pressure at the group head remain the relevant constant factor here? Surely 9 bar at the group head on a rotary or vibration pump model is the same thing, so the pumps might be pushing greater or lesser at the pump unit but measured at the important part, the head feeding to the portafilter if they both achieve 9bar then that should be what matters most, the pressure at which the heated water is forced through the puck?

[@TheEspressoTV]

No sorry this is wrong, you shoukld look at bernoulli and navier stokes equation in fluid dynamics for incompressable fluids.... A smaller pump capacity needs higher pressure than a high pump capacity in order to acchieve the same flow. ciao markus

[@robca8370]

+TheEspressoTV are comments being deleted? I wrote a rather long explanation on why it makes no sense to increase the OPV to 11 bar for a small vibration pump, and it was removed)

[@spidiq8]

+Rob Ca I noticed that post and found it interesting, shameful if it's been deleted

[@robca8370]

And it keeps being deleted... together with other comments. Here's the link with all the relevant information coffeegeek.com/forums/espresso/machines/711022. Let's see if it keeps being deleted, it's much easier now to keep re-adding the URL :)

[@BensCoffeeRants]

@@robca8370 Links down :p

[@wakeawaken430]

My Rancilio Epoca with vibration pump makes terrible coffee with the opv setted to 9 or 10 bar(Portafilter gage) When I set it to 12 bar, the coffee has taste and very nice texture, after that I realized that from the factory comes with 12 bar If you want low pressure, you must have rotary pump or a lever machine, fact Luca is right, I guess he decided to set some vibe machines to 9 bar cause the customers asked for it, and you can't change the tough head of someone

[@TheEspressoTV]

Yes this is not so easy to understand, it is fluid dynamics based on Navier Stokes equation. The best aproach by by tasting the coffee. You can also check the TDS by a refractometer

[@wakeawaken430]

@@TheEspressoTV unfortunately I don't have refractometer, but certainly I can taste the difference It's not only "better", the low pressure one is a heavy syrup without taste, without acidity and with very bad texture that makes you want clean your mouth

[@sbokhumsook1494]

I have question. Why is professional espresso machine usually not calibrate to 10 bar. Why ???

[@moafaq5703]

I saw another video when gauge says 11bar then it's 10 in grouphead, is that the same with BZ10? mine set to 11bar when using blind basket.

[@mz67]

Hi there. For the rule of thumb if your machine has only Static pressure Guage and vibration pump. Just keep it around 2 bar higher than 9bar with blind basket (11bars on static pressure gauge) the reason is there is always around 1bar pressure loss in grouphead vs the bar shown to you in static pressure gauge while Extraction. And since the the gauge is far away from the group in addition there is also another 1bar or even higher pressure loss vs the real pressure at the group head.(can be vary) Its because of water flow since the water pushed little by little by vibration pump the more distance it goes the more pressure losses. Yeah in rotary pump this is continuous water pump so there wont be much pressure loss in process maybe around 0.5bar. You can also check "whole Latte love" channel there's a helpful video they uploaded about brew pressure they actually test it with special portafilter with needle valve and pressure gauge to show you exact real pressure it works like espresso coming out but its like a simulation. You also gonna see around 2bar differences in gauge vs static gauge on machine.

[@kerembyl]

Is the value we read on manometer absolute or gauge pressure? In other words, is total pressure combined with atmospheric pressure or should we add atmospheric pressure additionally?

[@TheEspressoTV]

you do not need to add atmospheric pressure. What counts is always the pressure difference.

[@koaminsamudera235]

I just bought a VBM domobar with rotary pump. the brew pressure gauge show 12 when idle/standby. when the lever raised, it go down to 0 then go up to 10. Is this normal ? thanks .

[@TheEspressoTV]

This is unusual. But before making espresso always flush the group. Also afterwards... Sometimes pressure remains in the pipe.. This is nothing dagerous, but a bit strange... If you open the machine you see the thin tubes of the manometer, were some pressure can remain. ciaoo markus

[@koaminsamudera235]

Thanks a lot for your information, Markus!

[@user-hy1pv1cv4v]

Здраствуйте у меня кофе машина Faema enova A3 . У меня есть проблема с низкой температурой воды из подачи крана а точнее 76 градусов максимум 80 ! Из групп температуры в норме 87, 90, 91 , 🌡. А давления 1.3. Проблема в том что в инструкции четко пишут как прибавить и убавить температуру групп индивидуально ! Но про температуру подачи воды нечего не пишется ! Я пытался найти где может быть его регулятор но все зря там с болера нечего подобного нет! Не могли бы вы подсказать в чем секрет ? Спасибо я буду вам очень признателен !

[@TheEspressoTV]

The Faema Enova A3 is a very good commercial machine. In 99% of the cases with only warm water: the machine needs to be serviced, it is mainly caused by calc. Please have a look into the heat exchanger and the boiler. Please also check the heating element ! I think the reason is calc. The machine needs of cause 380V. With 220Volts you cannot operate.

[@PandaPandaPandaism]

This video has left me thoroughly confused. I have a Bezerra Crema that reads 12 bar with the blind basket in. I'm assuming this means it's 11 bar at the group head(the dealer explained this to me). I have noticed channeling is frequent with a hard tamp, but I've switched to a leveler which has allowed me to get more even extractions. Do I benefit at all from adjusting the OPV or not?

[@TheEspressoTV]

In my opinion it depends on your personal taste. If you are happy with the factory setting, why change it ?

[@PandaPandaPandaism]

@@TheEspressoTV I'm satisfied with the taste, but it's hard to know if there's much of a difference without testing at 9 bar. I will probably adjust it eventually, but I'm scared of harming the machine.

[@ahlandoit]

3:31 the best part

[@wakeawaken430]

Man of culture, your radar works fine 🤣

[@flyingfalafelmonster]

Bei meine Bezzera Unica der Pumpdruck ist sogar auf 12 Bar eingestellt. Bedeutet das, dass die Pumpe noch schwächer ist als bei andere Bezzera Maschinen? Die Kaffee schmeckt mir, obwohl Der Druck so hoch ist. Danke für diese Video!

[@TheEspressoTV]

Bezzera stellt das seit Jahren auf 12 bar ein bei Vibrationspumpen.

[@valemodsVD]

I have a Bezzera Magica and I’m really unhappy. I’ve spent $2k and I have a 12bar pump pressure that makes my flow too rushy! then they say, grind fine! Sure I grind fine almost to clamp all my grinds to get a decent flow but then taste sucks balls! When I set the opv to 10 bar with a blind basket, the coffee extraction is way better but the valve makes a terrible high pitch noise! do you know if that’s ok? is it gonna damage anything?

[@TheEspressoTV]

It is the frequency of the spring causing the resonance... If you disassemble the spring and change it or strech it a bit, then you change the frequency of the spring...

[@ferrei80]

I bought the BZ10 machine a week ago, but then the pump started malfunctioning during extraction, with the brew pressure fluctuating between 6-9 bars (dose/grind adjustments didn't help). After I took the machine back to the authorized dealer, the technician said the pump should have been factory adjusted to 9 bars. He claimed that the 11 bar setting caused the pump to prematurely malfunction (it needed replacement). He adjusted the OPV setting to 9 and replaced the pump. Who do I believe, and why am I receiving conflicting information from Bezzera and it's authorized dealers? I'm not impressed.

[@TheEspressoTV]

This is nonsense what the dealer says!!! But not everyone understands fluid dynamics acc to University level, shown in Bernoulli equation (incompressible media, laminar flow). The get the same volume /time with identical tube diameter the pressure is lower if the transported water amount in the pipe is higher. The pressure difference can be calculated by Bernoulli, with a flow of 100l/h of rotary pump pressure is 9 bar, with a flow of 35l/h (vibration pump) the pressure must be higher than 9 bar to acchieve the same flow... But do not mind, if Espresso flows out of the filterholder all is fine. ciao markus

[@rastislavstanik]

+TheEspressoTV the question is, are the diameters of tubes identical on various pumps then?

[@NM-bt6ct]

​@@TheEspressoTV Hallo, eine Frage: Was passiert wenn die Rotationspumpe 100l/h bei den 9bar Gegendruck am Puck fördert? Richtig, der Doppio wäre in unter 2s fertig. Das widerspricht allen Grundlagen. Ich denke für die Druckdifferenzen zwischen den Pumpen spielen andere Dinge eine Rolle, z.B. zusätzliche Strömungswiderstände vor dem Puck.

[@TheEspressoTV]

Ja natürlich das ist nicht so einfach, die kleinen rotapumpe hat 60 l/h. Man kann das mit navier stokes berechnen, 5. Semester stömungslehre. Der ausfluss bei rotapumpen ist homogener

[@NM-bt6ct]

@@TheEspressoTV Die Schwingungen sind aber vernachlässigbar, das sieht man ja auch am Manometer. Auch bei 60l/h muss die Flussrate begrenzt werden. Ein Doppio in 4s ist nicht besser. Zeigen Sie ihre Berechnung. Ich bin mir sicher, dass ich einen Fehler finde.

[@jimbobjohnson469]

I have a Bezzera BZ13 DE and mine is 12 bars of pressure when pulling a shot is that to high

[@TheEspressoTV]

No that is ok. With bypass valve adjustment you can adjust the pressure acc to your needs... In general this adjustment is for tecnicians.

[@TheEspressoTV]

I cannot read your link to the differences, but in fact both pumps are totally different in their pump curve - The operating design point of a pump lies at the intersection of the pump curve and the pipe curve... At least I can say that I did engineering for plants for some years. But in the tasting result there is not so much difference I have to admit.. I personally prefer the rotary pumps, they are not so noisy. Ciao markus

[@TheEspressoTV]

You can check / caculate easily yourself by application of Navier stokes equation for incompressible fluids and laminar flow, plus bernoulli equation.

[@DRTESLAKIS]

Hi , my Cime machine ( rotary pump ) has dynamic pressure 7 bars and static rise to 10 when put blind basket ! Is this normal ?

[@TheEspressoTV]

you can adjust the pressure at the pump screw. Normally 9 bar is perfect during extraction, 10 bar with blind filter is ok.

[@jonr5000]

You say over and over that you need more pressure, but you don't clearly explain why. I'm going to guess that the problem is that on the smaller machines, 11 bars at zero flow results in 9 bars when a shot is flowing. But it would be better to measure and set the pressure with flow instead of measuring at zero flow and then trying to correct the measurement by adding two bars.

[@TheEspressoTV]

No,you do not understand the function of a vibration pump. It is calibrated at 11 bar, but the pressure on the brew unit depends on the amount of grounded coffee and the grinding degree and the tamping pressure. Good extractions are acchieved with vibrationpumps between 10 and 11 bar extraction pressure at the group. You can check it at the manometer of the brew ghroup, but you see it in the result of the outflow and in the creaminess of the espresso.

[@mz67]

Hi. Ok it's been a long time since this video uploaded. But i noticed you're still answering :D I got bezzera bz10 recently and it shows me 12bar pressure with blind basket hmmm.. Interesting right? Why 8 years ago it suppose to be fixed at 11bars now it's 12bars.. I actually changed the pressure to 9.5bars and still confused why you claiming that 9 bar pressure on the rotary pumps= 11bar on vibe pumps(my bezzera were fixed at 12bar tho lol!) You told that rotary pump can push way more water than vibe pumps ok that's so true but who cares i mean u just extracting max 60-100mil (lungo shot) you're not gonna fill up pool with that pump! i really confused still because im getting stable 9bars on my coffee puck which is actual 9 bars isn't it?!?! I mean my machine shows me 9 bars then what's up with 11bars and now 12bars factory set?!? Pffff I'm mad cause there's not enough explanations here. Please tell me what should i do. Should i turn the pressure back on 12bar (factory set) or the 9.5 bar (that i set on opv adjustment with blind basket) completely real 9.5bar like rotary pumps?.(i did 9.5 bar because when the water goes to the coffee the pressure goes down abit so it's 9bars) Just help me sir!!!!!!

[@aaronfinney2439]

​@@mz67 The pressure is dependent on two things, a) the force of the thing pushing the water (the pump) and b) the volume of water being pushed in relation to the amount of resistance in the line (the coffee in the portafilter). Think of it this way: say you have a small hand pump with a piston in it that lets you push water through a length of pipe, but you have a 10' long lever connected to that pump that you can use to apply 100 bar of pressure to the piston. What would the pressure be on a gauge attached to a the end of a length of pipe fed by that pump? At first it would be zero...then as you fill the pipe with water, pressure will continue to rise until eventually the gauge reads 100 bar. Now imagine you're pushing the water through the same pipe, but this time you've installed a needle valve somewhere in the pipe to allow some water to escape. At first, the pressure gauge on the end will show zero bar, but eventually you'll be able to pump enough water into the pipe to fill it and the pressure will continue to rise as you pump. However, depending on how much water is allowed to escape, you will never quite get to 100 bar; as you increase the pressure, the rate of water escaping increases, which in turn lowers the pressure in the line. If you had a larger pump (a pump that moved a higher volume of water), it would take much less work to a) get to the max pressure and b) keep the pressure at the max. In the case of a small vibe pump in an espresso machine, it might show you 12 bar with a gauge on a portafilter with no water escaping the system. But as soon as you start letting water escape (like when water goes through a coffee puck), that pressure is going to drop, because the pump is not capable of moving a high enough quantity of water to keep the pressure at the max the way a larger rotary pump can. Make sense?

[@mz67]

@@aaronfinney2439 i understand all your explanations. But in case of brewing espresso the water quantity is pretty much low volume so result in the bigger pump or smaller pump they both do pretty nice job (they both put lot less effort than their actual horsepower to push that little water for espresso in 12 bar or whatever)(like grown man vs child both can easily lift bottled water) The clues i find out on machines either rotary or vibration they both have pretty much same Pressure loss in their way especially in groupheads. Bz10 has 1 or 1.5bar loss pressure at group head (actual brewing pressure or dynamic pressure) so you'll may need set your static pressure(gauge pressure on the machine) with blind basket around 10.5bar to get 9bar at grouphead (i checked this with manometer Portafilter with needle valve) I got the same result on rotary pump as well as vibration pump but in home machines not commercial ones. The only benefits of rotary pump are the consistent water pushing (if you check the mechanism you'll understand) but the vibration pumps are pushing water little by little like cylinder, on ex5 pumps i think it's 50hz. With that being said I'm not trying say they both put same effort to push that water I'm pretty sure vibration does little more effort than rotary. But in case of espresso they both do nice job.(the pressure build up on 9 bar which everyone looking for is quite the same on rotary or vibration Yes on 100bar for sure vibration loses and for filling i don't know like for pool for sure vibration loses.)

[@tavomald]

Hi, I have a small Bezzera BZ99, I want to know how to increase the steaming pressure, Is it possible? Thank you much

[@TheEspressoTV]

You adjust the Mater pressostate acc to your wish.

[@tavomald]

@@TheEspressoTV thank you so much! I had not seen the reply up until now. got another question for you. For Bezzera PB2000, the espresso flow is not continuous/consistent. Would the pressostat adjustment would also help in this case? thanks again, best regards and keep safe

[@wiloghby]

Bezzera now ships these machines with the OPV set to 9 bar, and also sells a kit for converting 11 bar machines to 9 bar. So maybe you can make a new video explaining why Luca Bezzera was full of shit?

[@TheEspressoTV]

You can set the machines kombi valve like you want, it is up to the customer, the machines with viobration pump delivered by Bezzera are set up with 10 to 12 bar, if you put a filterholder with blind filter you can check. The adjustment of the kombi valve can be done easily(eg BZ10: page 5 number 11, 5965165, ASSEMBLY SURPRESSION VALVE) This conversion kit is not necessary at all. You just adjust the Bypass valve with the spring acc to your personal taste, I guess this is the best.

[@stephenstephen74]

9 bar or 10 bar is not an indicator, it Will depend on what brand of ur coffee machine, what kind of pulp. Even the same rotary pulp technology but will be diffrent output power. Some brand not quit strong but others brand so strong the pulp result The impotant thing is, we need to try the result of our machine, start from 8 bar to 11 bar. If it taste sweet and not too bitter, and smell good. Its ur right measurement of bar, so need not to imitate the measurement bar of others recomendation. As my result, the higher bar, needs very small grind size, and the water flow Will never stable, they Will start from slow water flow and then suddenly very fast water flow. But if u reduce the bar presure, the result Will be more stable of water flow, even at the end the water flow Will be faster, but the speed gaps of the first water flow and the end of water flow still not significant change.

[@ficokan]

I came to the same result during taste testing. 11bar is hard to work with in order to produce consistent shot. Maybe it can start good but from the middle of extraction to an end, it becomes fast and channeling occurs. On the other hand, in my experience, on vibration pump, lower than 9bar is also not gonna make nice espresso. So I end up setting Appartamento on just little over 9.5 with blind basket. In most cases, real extraction is right at 9bar.

[@valemodsVD]

If small machines with small pumps like that are low quality and they need higher pressure, compared to big rotary pump commercial machines, then why Lelit makes small machines that perfectly deliver 9bar pump pressure with no problems? is it because bezzera is turning into breville?

[@TheEspressoTV]

You can adjust the pump pressure yourself at the bypass valve acc to your personal taste. If you cannot do, a local dealer should be able to adjust it. It takes half an hour with disassembly of the stainless steel chassis

[@valemodsVD]

@@TheEspressoTV i did it first thing when i bought my bezzera magica and noticed the brutal flow/pressure of the machine. But when i go anywhere lower than 11.5 bar (reading on the pump gauge) it makes a terrible high pitch metal harmonic sound while extracting or back flushing. It doesn’t sound right. What is it? can it damage components of the machine if ignored in a long run?

[@JoernConrad]

Auch wenn das Thema nun schon ein wenig älter ist, aber ehrlich gesagt erschließt sich mir die (eigentlich gar nicht vorhandene) Erklärung nicht! Klar ist, das eine Rota-Pumpe mehr Druck aufbauen kann und bei gegebenem Druck einen höheren Volumenstrom ermöglicht als eine Vibrationspumpe. Es ist aber auch so, dass beiden Pumpen einen gewissen Headroom haben, also einen Überschuss, der durch das Bypass-Ventil abgeleitet wird und in Abhängigkeit zum Durchfluss steht. Wenn ich nun also meine Vibrationspumpe bzw. den Bypass gegen ein Blindsieb auf 9 bar einstelle, dann zeigt das eingebaute Manometer meiner VMB Domobar 9,4bar - also 0,4 bar mehr als letztendlich am Siebträger ankommen. Der überschüssige Volumenstrom wird dann über den Bypass abgeleitet. Wenn ich nun einen befüllten Siebträger einspanne und der Bezug läuft, dann zeigt das Manometer der Maschine ca. 9,2 bis 9,4bar. Das hängt natürlich von der Befüllung und Komprimierung des Siebes ab. Heißt also, dass in Fall meiner Maschine ca.8,8 bis 9,0bar am Siebträger zu erwarten sind. Und jetzt kommt die relevante Aussage: Der Druck ändert sich auch während des gesamten Bezuges nicht, so dass davon auszugehen ist, dass die genannten 8,8 bis 9,0bar ebenfalls die ganze Zeit anliegen! So, und spätestens jetzt mangelt es mir ehrlich gesagt an der Einsicht, warum man plötzlich eine Vibrationspumpe auf 11bar einstellen sollte....??!?? Und selbst die Aussage eines Herstellers, die leider keine Begründung enthielt, ist mir ehrlich gesagt schnuppe, solange ich keine plausible Erklärung bekomme. Und ganz ehrlich.... Einfach nur die Angaben des Gesprächspartners wiederzugeben, ohne diese zu hinterfragen,.... Aber na ja. Meine Maschine war ab Werk auf 11,7bar eingestellt und der Geschmack war alles andere als ausgewogen. Nachdem ich sie auf 9bar eingestellt habe, lässt sich der Espresso plötzlich auch fein einstellen. Aus meiner Sicht spricht wirklich nichts für die Aussage, eine Vibrationspumpe bräuchte mehr Druck! Man KÖNNTE vielleicht noch über die Wellenbewegung argumentieren, die sich aus der 50Hz-Frequenz ergibt, aber die sollte sich eigentlich nivellieren. Aber wenn jemand eine plausible Erklärung für mich hat, immer her damit! ;-)

[@TheEspressoTV]

Hallo jörn, Ich frage mal meinen Studien Kollegen, der ist jetzt Professor an der tu Karlsruhe ( heisst jetzt kit oder so). Was ganz klar ist: eine vibrapumpe hat als kennlinie eine zackenlinie, eine rotapumpe fördert konstant, hat eine ganz andere kennlinie. Der kaffeeausfluss ist auch unterschiedlich je nach Pumpentyp. Das ist das, was man äußerlich beobachten kann. Den Teil drr strömungslehre bleibt einfach mal unberücksichtigt. Meine Empfehlung: nicht verrückt machen lassen, wichtig ist dass der espresso schmeckt und Mühle und Maschine nicht voll mit ranzigen Fetten sind.

[@JoernConrad]

Diese "zackige" Kennlinie ist wohl das, was ich mit wellenförmig meinte... Wäre mal interessant, was ein Physiker dazu sagt. Das hängt dann sicherlich auch vom Hub und Volumen der Pumpe und dem damit zusammenhängenden kurzfristigen Druckabfall auf x bar während der Rückzugsphase des Kolbens zusammen. Aber es stimmt schon... Hauptsache, es schmeckt ;-)

[@m4tth3wh]

So the Bezzera domestic espresso machines with ulka pumps set at 11 bar. Does this equate to approx 9 bar at brew head during extraction?

[@mz67]

I'm so tired of searching man... I got bezzera bz10 recently and the pressure on blind basket set at 12bars... Huh! Interesting right? Cause in this 8years old video the pressure had been fixed on 11bars. Come on! Im confused beacuse they claim vibe pumps need 11bar pressure to achieve 9bar pressure on rotary pumps! And now my machine after 8 years is fixed at 12bar. Im just f*cking tired!. I actually change the pressure on 9.5bar and now im confused.... Can you tell me what should i do! I just want someone to tell me is that 9bar pressure i set on my machine is actual consistent 9bar on my coffeee puck..... I just can't understand... HELP ME PLS

[@wakeawaken430]

@@mz67 if your coffee lost taste, texture and nice acidity with 9.5 bar, set it back to 11-12

[@ghislaincarrier]

I finally understand. Like many, I thought it didn't make sense. But when looking at the comments I noticed something important: SAME FLOW RATE. If with the same grind setting, same amount of coffee you want the same flow rate (same extraction time), you need to let the small pump push more water. You do this by increasing the pressure so more water goes to the coffee and less goes back in the tank. If I take back the analogy with cars. If you have 2 cars with the same gear ratios but one has a more powerful engine. In 5th gear the RPM is the same on both cars since the gear ratios are the same. when you climb a hill, the powerful engine will be able to climb the hill on 5th gear but you have to downshift to 4th gear on the small engine which results in higher RPM (pressure) if you want to keep the same speed (flow rate). So the small engine works harder. In this analogy, the slope of the hill is the grind size and the height or length is the amount of coffee. So if you can use 9 bars on the small pump, if you reduce the amount of coffee, grind coarser or accept a slower flow rate. Sure the coffee will taste different. Official Speciality Coffee Association definition of an espresso is "...has been forced at 9-10 atmospheres of pressure, and where the grind of the coffee is such that the brew time is 20-30 seconds..." so based on this, the small pump should be set at 9-10 bar and we should instead adjust the grind size to have the same flow rate as the larger pump. :)

[@marcozg77]

Ich habe mir eine kleine Quickmill Orione 3000 zugelegt, und bei 9 Bar rasselt der Espresso viel zu schnell durch und schmeckt wässrig. Bei 11-12 Bar ist er viel besser. Danke für das Video, ich dachte schon ich spinne...

[@patanostra1]

SPITZE!! Danke für diesen augenöffnenden und tollen Beitrag! Ich stelle meine VBM nämlich seit Jahren nur nach persönlichem Geschmack ein und bin seit Anfang an bei 10 bis 11 Bar. Übrigens musste ich feststellen das es auch mit den 7 Gramm Kaffeepulver bei der VBM nicht hinkommt, ich muss immer ein bissl was nachfassen um das gewünschte Ergebnis zu erhalten. LG Rudi

[@stevehopper8086]

guess my grinder can't go any finer, so set my Bezzera Unica to 9 bar, and now my coffee doesn't flop out in 12 seconds any more.

[@TheEspressoTV]

Yes exactly....

[@cod3r1337]

Alles schön und gut, aber sogar im Handbuch meiner Bezzera Magica steht im Troubleshooting-Teil, dass der Druck nicht > 10 Bar sein sollte und man bei höherem Druck einen Techniker konsultieren sollte. Lt. Manometer erreicht die Pumpe aber stets 11-12 Bar. Ist das eine Ungenauigkeit im Handbuch (das ja gleichzeitig für die Mitica geschrieben ist), oder mache ich was falsch (Mahlgrad, Dosierung, Tampen)? Alles sehr verwirrend für Anfänger!

[@YouDabian]

cod3r1337 10 Bar könnte genügen, glaub ich. Wie schmäht der Espresso? Um welches Pumpe geht es?

[@cod3r1337]

Der Espresso schmeckt sehr sauer. Das kann aber auch andere Gründe haben. Die Magica hat eine Vibrationspumpe. Ich glaube aber, dass einfach das Handbuch meiner Magica fehlerhaft ist, weil es auch für die Mitica geschrieben ist. Die Mitica hat eine Rotationspumpe - auf Unterschiede zwischen Eigenschaften der Pumpe bei Magica und Mitica wird aber im Handbuch nicht eingegangen.

[@TheEspressoTV]

Das ist ein Fehler im Handbuch.... ich werde es an Bezzera weiterleiten, danke für die Info. Viele Handbücher gehören insgesamt etwas überarbeitet. Ich selber habe schon 2 bei Bezzera (Dt und Englisch) korrigiert.Ciao Markus

[@cod3r1337]

TheEspressoTV Alles klar, vielen Dank für die Info! Das ist glaube ich das erste Mal, dass ich über YT-Kommentare zu nützlicher Information gekommen bin! :-) Gibt es eigentlich einen Newsletter von Bezzera für aktualisierte Handbücher und ähnliche Informationen?

[@TheEspressoTV]

Nein so weit sind wir hier noch nicht, die Handbücher dienen meines Erachtens nur als erste Orientierung. Es gibt nicht so viele Leute, die das alles durchlesen.Wichtig ist, dass der Espresso (25ml in 25 sec idealerweise) schmeckt und die Gerätschaften sauber sind und richtig funktionieren... Bezzera weiss aber, dass es hier noch Nachholbedarf gibt.

[@Dino-ir4or]

Oh Mann... also muss ich mein EX-Ventil jetzt so einstellen, dass es zw. 10 und 11 bar liegt, gemessen mit einem Siebträgermanometer, wenn ich ne ULKA habe. Die ist in meiner Isomac Millenium nämlich drin. RIchtig? :-)

[@TheEspressoTV]

nicht unbedingt. Wichtig ist, dass der Mahlgrad passt und die Kaffeemehlmenge, der Druick ist aus meiner Sicht sekundär. Aber besser ist es, zumindest bei 10 bar zu landen. Ciao Markus

[@Dino-ir4or]

TheEspressoTV Guten Morgen Markus! Ist es nicht ein Unterschied, ob ich (bei konstantem Mahlgrad und Kaffeemehlmenge) das Wasser mit 9, 10 oder 11 bar durchdrücke? Die Flussgeschwindigkeit erhöht sich doch, je höher der Druck ist. Nach meinem Verständnis würde das bedeuten, dass ich bei höherem Druck feiner mahlen muss, um die z.B. 25ml in 25 Sek. zu schaffen, weil ich einen höheren Gegendruck im Puck erzeugen muss, richtig? Die Frage ist jetzt nur, was bedeutet das für den Geschmack, wenn ich Espresso aus feinerem Kaffeemehl produziere, weil sich die Extraktionsmenge durch den feineren Mahlgrad (= mehr Kaffeepartikel bei gleicher Grammzahl) erhöht?

[@Dino-ir4or]

Hey Markus, liege ich komplett falsch mit meiner Annahme? Sag mal was :-)

[@TheEspressoTV]

Dino Rebstock Ja Dino, bei Vibrapumpen sind 10-11 bar besser! Bei Rotapumpen sind es 9 bar. Das kann man mit der Bernoulli-Gleichung für inkompressible Medien (Strömungslehre) nachrechnen, am besten unter Vernachlässigung der Verluste in Rohrleitungen (die von der Rauigkeit der Rohrleitung und dem Fließverhalten des Mediums, in diesen Falle erhitztes Wasser, abhängen) ... Aaaber: wichtig ist, dass in 25sec in etwa 25ml Espresso extrahiert werden.. Und das wichtigste ist: der Espresso sollte einem schmecken :)) Also keine Doktorabrbeit draus machen :) Ciao Markus

[@Dino-ir4or]

Also gut :-) Dann mache ich es mir einfach. Zählst du die 25 Sek. ab Bezugsstart oder ab dem ersten Tropfen, der aus dem Siebträger kommt? Hier scheiden sich ja die Geister. Was sagt der Profi dazu?

[@DavidSanchez-ls6nk]

This does not make any sense to me. The pump of a domestic coffee machine is not big enough and so you increase the pressure on it? How can this be? Sorry for my ignorance but I really do not understand this demonstration. If anything you would decrease the pressure to lessen the strain of the small pump on the machine. If the pump is already struggling at 11 bars then you should, again, if anything, decrease the pressure to 9 bars, not the other way around. ???

[@TheEspressoTV]

Dear David, it all does not matter so much. It is only a basic fluid dynamics study. So do not take it too serious. If a small pump has a capacity of 15 liters per hour, then you need a bit more pressure than a pump with a capacity of 60 or 100 liters per hour. With Bernoulli equation you can calculate it, Navier Stokes is not really very necessary. Here is a good and easy understandable link for engineers, maybe it helps: www.khanacademy.org/science/physics/fluids/fluid-dynamics/a/what-is-volume-flow-rate Ciao Markus

[@DavidSanchez-ls6nk]

Thank you Markus. I am only saying because I have just turned the pressure down on my Gaggia to 9 bars and wanted to find out whether this was alright to do, and then I found this vid on youtube. Anyway, it turns out that I have tested it with a coffee and got what I expected: a lovely coffee with the perfect crema. And I also found the Gaggia to be going smoother than before. It is all good Markus as this encourages questions and hopefully with it some answers, maybe some better than others, but all good nonetheless. Thank you again Markus for being so informative and for your quick response. Cheers D

[@TheEspressoTV]

Yes this is the main point, to be flexible in the mind, not to be scared of testing and enjoying :)))

[@dominicschmidt1016]

TheEspressoTV No Markus. The pump capacity would only matter if you actually want to extract more volume than that. But 15 Liters per Hour is already plenty assuming a 40~60ml shot in 25-35s. But assuming you would want to extract a lot more than a standard shot, you would have to grind coarser and coarser until you hit max pump capacity at the pressure set at the OPV. Grinding even coarser (or less coffee or simply no coffee) would mean the pressure at the head would now drop. Before you reply with a reference to the Bernoulli equation, I would politely urge you to speak to anybody with a university physics degree. You mistake fluid velocity in the equation with flow rate. Rather than a generic reference to Bernoulli, please explain how you can have different flow rates at the same pressure for any given system.

[@benko2910]

Sorry, but it is total none-sense. Lets see it from a logical perspective and with a little bit knowledge of basic flowphysics. Lets assume that the Espresso in the portafilter will always remains constant. By a given resistance (Espresso in Portafilter) and the same pressure (measured directly in the brewhead) the flow is absolutely the same independently of the type of pump. If the pump is too weak (too low flow) the resulting pressure will also be lower. If the flow will be higher, this would mean you will have a higher pressure in the brewhead. Sry, I must warn everyone not to believe what is said in this video. However, there may be other reasons to have an advantage with higher pressure and vibrationpumps (dynamic effects?).

[@kamrandiba40]

This doesn't make sense. Why make the small pump work even harder than needed?

[@TheEspressoTV]

Hi The answer is in fluid dynanmis - navier stokes. Bibration pump has a 15 liters per hour capacity whereas a rotary pump has 60 to 100 liters capacity. Therefore rotary pumps need lower pressure.... And the extraction is a bit better.

[@williamargiris5521]

+TheEspressoTV the procon pump are also installed on 2 - 3 even 4 group coffee machines (for 4 group you need 160lt pumps).. so they have to have the volume to keep up for the demand of the user

[@kamrandiba40]

But Navier-Stokes and Bernoulli equations both depend on flow velocity. The flow velocities are the same for all espresso machines, regardless of the pump capacity.

[@NameNaameNameeNaamee]

You need a certain amount of water per minute coming through. To get the same amount of water per minute, a smaller pump has to operate at higher pressures. A good Ulka pump will have no problems with this by the way.

[@kamrandiba40]

NameNaameNameeNaamee I see that's what you guys are saying, but I don't see the scientific reasoning behind it. It's like you keep telling me that heavier objects fall faster.

[@dietmarvillanova6815]

Sehr amüsant. Das würde auf ein Auto übertragen ja bedeuten, dass ich mit einem kleinen Wagen 110 km/h fahren müsste um genauso schnell zu sein wie wenn ich mit einem großen Auto 90 km/h fahre :-) LOL . Physik mal völlig neu erfunden oder die ganz spezielle Relativitätstheorie E=Kaffeequadrat (Ich schmeiß mich weg :-))) )

[@NM-bt6ct]

😂 Die Erklärungen ergeben bei genauer Betrachtung der Strömungspfade wirklich keinen Sinn. Könnte es nicht auch sein, dass die günstigeren Vibrationspumpen-Maschinen, anstatt eines öffnenden Magnetventils vor der Brühgruppe, ein mechanisches Ventil besitzen, was beim Fluss zu einem Druckabfall führt? Das würde den höher eingestellten Blinddruck plausibilisieren.

[@TheEspressoTV]

well, this is very basic in mechanical engineering of fluid dynamics for me to explain, but fluid dynamics does not understand everyone. It is Q=v * A. So I try to explain it with cars and not with math. A V8 4200ccm cylinder motor needs less rpm than a 2 cylinder 2CV motor with 600ccm to each the same speed. Similar it is with pumps, the rotary pum has much much more capacity, so it needs less pressure... Ciao Markus

[@reidjam7]

Simply put, flow (volume/time) is defined by the pump. Static pressure is independent of flow. Obstruct flow and pressure on the two pumps will each reflect the maximum pressure either at which the pump is set (rotary), or of which the pump is capable (vibe). Now relieve the obstruction and we are now dealing with dynamic pressure. If flow exceeds the capacity of the pump, disregarding friction loss from the piping for the moment, pressure will drop. If the pump is capable of delivering the required flow, it does not matter what it's maximum capacity is. That only bears, possibly, on the likely lifetime of the pump-- if we use a pump at 90% of its rated capacity (vibe) vs. 12% (for example-- arbitrary made-up percentage), the wear and tear on the rotary is going to be significantly less, hence it's going to last longer qualifying it for the "professional" epithet. I guess I'm not convinced that the vibe pump's OPV needs to be set at 11 bars "...to give it more oomph.". Seems to me, instead, that measuring the actual flow and pressure would be the best way to set the OPV valve. Of course, since you can't adjust the pressure directly on a vibe pump the way you can on a rotary one might employ a method suggested elsewhere in a coffee forum by "Another Jim" (Jim Schulman) to insert a blind filter and measure the flow, after a 10-second warm-up, out of the overflow tube. He suggests that a flow of 2.0 to 2.5 oz. (200 to 215 ml.) in 25 seconds will result in the actual brew pressure at the head being about 9 bars. Taste matters! Cheers all.

[@drax14QC]

My home espresso machine has 15 bar pressure...! 😬

[@TheEspressoTV]

9 bar pressure with a rotary pump gives much better results. 15bar means the MAXIMUM pump pressure. This is written on the pump. Above 12bar extraction pressure the coffee gets quiet bitter...

[@drax14QC]

TheEspressoTV yeah, well I can only work with what I have. I’m still enjoying my espresso at home but I know I want to upgrade to a better machine some day ☕️ thank you for your response and your great videos!

[@gaborudvardi9402]

To make an espresso you need around 30-50ml water pumped at 9 bar in 25-30 seconds. It's not a big deal for the small Ulka vibration pump. Anyway, for higher pressure, with same flow, you need more powered pump, so what you tell in this video is not logical. I think the manufacturers use 11 bar pressure in consumer machines for other reason.

[@TheEspressoTV]

It is a little bit more complex unfortunately... For math calculation the Navier Stokes equation is quiet helpful (flow dynamics). The flow differs acc to the pump type - therefore espresso machines equiped with vibration pumps often have a bypass adjustment... so everybody can adjust the bypass flow rate acc to his personal taste. IN case just ask the tecnician of espresso machines, they can adjust the bypass flow.

[@CapnCrusty]

Worst sub title generation for a video that I can remember. It's completely beyond understanding, and this is a topic of which I wanted to know more. Sad.

[@williamargiris5521]

1 . there vibrating pump are not adjustable 2.this pump works constantly at 16 bars 3.the way this pump is adjusted is by a valve witch is connected after the pump that is not adjustable ( any execs water goes back to the water tank that is why you see 2 tubes in the water container ) 4. the valve on the pump allows 9 bars o pressure and again it is not adjustable 5. this guy is full of shit

[@TheEspressoTV]

Vibration pumps are adjustable by the bypass valve, and the max pressiure shall be not above 12 bar. Kind regatds markus

[@williamargiris5521]

+TheEspressoTV maybe you should make a video , to show all these people how to adjust the vibrating pump to 12 bars.. I would love to see it

[@TheEspressoTV]

Good idea, i put it in my Agenda Ciao markus

[@Sander.Osephius]

kzbin.info/www/bejne/boeZd2aPbNZqoJY This is the way to adjust the valve pressure. I've done it with my Bezzera Magica, it works perfectly. I do have to say that there are much more important things that influence the quality of a shot than the pressure. Quality and freshness of your coffee, the grind, consistent tamping, brew temperature etc. have far more influence then a bit more or less pressure.

[@jacksos101]

Smells like BS to me.

[@mz67]

As it is haha

[@mz67]

For the rule of thumb if your machine has only Static pressure Guage and vibration pump. Just keep it around 2 bar higher than 9bar with blind basket (11bars on static pressure gauge) the reason is there is always around 1bar pressure loss in grouphead vs the bar shown to you in static pressure gauge while Extraction. And since the the gauge is far away from the group in addition there is also another 1bar or even higher pressure loss vs the real pressure at the group head.(can be vary) Its because of water flow since the water pushed little by little by vibration pump the more distance it goes the more pressure losses. Yeah in rotary pump this is continuous water pump so there wont be much pressure loss in process maybe around 0.5bar. You can also check "whole Latte love" channel there's a helpful video they uploaded about brew pressure they actually test it with special portafilter with needle valve and pressure gauge to show you exact real pressure it works like espresso coming out but its like a simulation. You also gonna see around 2bar differences in gauge vs static gauge on machine.

[@mz67]

This video is super annoying no explanations and real tests.. Just bla bla.