THE TRUTH ABOUT ESPRESSO: Understanding Espresso Flow
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- Опубликовано: 15 июл 2021
- I take a deep dive on profiling espresso and look at terms like water debit and puck resistance. If you enjoy learning about or drinking espresso, I suggest you watch!
NOTE- The Decent Espresso Machine is not 100% on knowing input flow. It estimates the flow based off a complex algorithm. Supposedly, it has a 20% bias, which is quite impressive.
ANOTHER NOTE- Parts of the video sound like I am saying water debit is a constant throughout the duration of the shot. Please know that is NOT what I mean. The OPV not only shunts flow to bring pressure down, but the pump itself lowers the flow rate once pressure rises, hence my equating espresso flow with input flow.
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FREE Smart Espresso Profiler App referenced:
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Resource on Profiling:
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Развлечения
Aww yes, what you describe here is the outcome of fluid mechanics which so few videos explain. Liquid flow through a packed bed, which is typically modeled with the Ergun equation. You can set the flow, the pressure drop and the characteristics of the coffee bed, but if you fix two of the three then the third is fixed as well. Grind parameters and bed characteristics effectively change the void fraction, sphericity and particle diameter which are the inputs to the equation besides flow velocity and bed pressure drop. Really great video!
Appreciate it, Patrick! Thanks so much
I'm not a barista, just someone who bought an espresso machine and decided to make good espressos and simple latte art. I was not able to come close to making shapes, not even getting the foam down at all until I found your channel. Now I can make hearts and I don't have many practice cups in. Your style of teaching is perfect for me and I'm so happy I found you. Thank you for all your work, the information is so valuable!
Lance: Yo yo yo, *slow* your flow! 😁😂
Hahaha!
I shot straight to the comments after that 😭
Bars
(pun wasn't intended, realized after)
My sense is that we'll look back in 5 years to how we've thought about pressure the same way we look back at obsessing over shot times. Yes pressure (and shot times) are helpful indicators, but they're only a way of getting insight into the main variables we actually care about. In the case of pressure, an indicator for flow and resistance. For time, an indicator of dose:yield, temperature, and flow/pressure.
Super helpful video! Thanks man!
Seems to me that folks are mostly obsessed with weight (18g in, 36g out), yet I’m finding shot time is the biggest determinant of flavor profile. Number of seconds from first drop to end of shot. Yes there are variances. If I pre-infuse, I get a richer looking crema… but it doesn’t last quite as long in the cup. Likewise with flow control, I can have a bit more or a bit less in the cup as desired. But with or without pre-infusion etc, if I count X number of seconds from first drop out to end of shot the flavor profile remains consistent. So if we want consistent results, the shot time is the first item to make non-variable.
If only all of the teachers of the world presented with passion and knowledge like this.
Thank you so much! Means a lot, friend.
I absolutely appreciate this video! Your summary at the end is fantastic. Thank you Lance!
Wow, that was super good and informative! Thank you Lance!
What an amazing video… I never understood why everyone was crazy about setting OPV to 9 bars and where often on very geeky forums they would say that doesn’t matter, the grind size does. Now I understand: if the OPV kicks in at 9 bars or higher, well that means your flow will just not be right. So whether it hits 9 bars or not does not matter. THANK YOU. It was so good I’ll subscribe to your channel, it is my first subscription ever.
after years of using a LMLM i just got a Lelit Bianca to play with... this video was exactly what i needed!... keep up the good work
I was always struggling to dial-in espresso, and this video was so helpful to make me understand what is my machine is actually doing when we say it brews coffee with pressure haha. Thanks for this great video again Lance! It was super understandable and helpful! Hope you have a nice day, and cheers!
Pete.
Thanks man...nice workflow. There are differences in design of machines. OPV valve is a security mesure in commertial machines. They have a main water supply plugged directly to coffe boilers. Pumps are set to 9bars and OPV valve is set to 12-15 bar. If the pressure reach 12-15 bar,OPV will open and relase the pressure to the drain. Machines with vibration pumps and water tanks...the pump delivers 15bar. And OPV is set to 9bar. So it is constantly returning water to the tank. Hx machines also have restrictions in thermosyphon pipes to control the flow.. We had good and bad espresso 40 years ago and with all the new technology we still have good and bad espresso. Just enjoy and have fun. Thanks again for your point of wiew.
You are correct. Yep.
Wow. I just posted a homebarista post about water debit and this is by far the most comprehensive and thorough explanation on the topic I've found
Great video Lance, thank you - both the delivery of the content and the quality of the editing are awesome
Thank you so much! I appreciate the support
Awesome video! I finally decided to download the se profiler app. On the first go I decided to record the flow profile of my usual manual pull on my Flair Pro 2, which is essentially a slow decline in pressure after a preinfusion and ramp up to 8 bar. It was affirming to see I pretty much followed a constant flow rate after I reached the initial peak pressure. Excited to now use the app as a guide.
the only reason that make this easy to understand is you , I love the way you explain things really thank you bro!
Great video, I finally understand the actual concept when using the flow control on my Profitec and why I was having problems. Thank you
Very good video Lance.. When you start playing around with pressure profiling and flow control it opens your world up..if you can use this on your machine the whole 25/30 second shot gets blown out the window
Hey Vsauce, Lance here!
As a person passionate about education and making anything captivating and easy to understand, I profoundly admire you. I use you as an example to students regarding how one should explain something clearly.
You have a very rare talent! Congratulations!
...or are you??
Lance, you’re a legend. Took me a long while to figure this stuff out, wish I’d had this video to watch!
Thank you so much!
Look at your channel growing! Love every video
That's what I need -- a video on the Gaggia Classic Pro! Thank you!! Looking forward to it!
Really great video of a complex theme! Thank you!
Brilliant video! I’ve been playing around with my Bianca, trying to replicate some of the Decent profiles, too. Thanks to your explanation, I don’t need to worry anymore about not having understood the concept. You really break it down very well 😊
That's what I have man...I normally go long pre infusion ramp right up then finish around 6 bar.... Works awesome with light roasts
My man Lance always packing with great information
Lance, I saw your video on turbot shots, and I found this new video to be ALSO very clear and easy to follow. Thanks! I have a Rancilio Silvia V6, which means that I cannot control either the water debit or the pressure limit, but it really helps to understand clearly that when I am adjusting (1) the grind and (2) the degree of tamping provided by y Distribution Tool and (3) the number of grams of coffee in the basket, that I am adjusting all these things to manage, not the pressure, but the water flow. - Toby (a subscriber)
Hey! Thanks so much for the comment. I will say, im pretty sure there are easy to perform mods you can find online to change the pressure! I'd give home barista a perusal
This blew my mind. Awesome stuff 😎
Thank you so much for this video. Im just getting into the home espresso world and this really helped me understand the basics.
Fantastic! So happy you found it useful. Thanks for the support
That was a joy of explanation!
Thanks for introducing me to Decent Espresso! I cannot wait to get one.
Hey Lance, great video! This is some of the best content I've seen on demystifying how the flow/pressure relationship actually works on espresso machines.
Thank you! That means a lot. Appreciate you taking the time to comment and helping others in the comment section!
@@LanceHedrick Glad if I can help. Hopefully I haven't confused anyone further 😅 The complexity increases rapidly in this subject, and some people in the coffee industry use engineering terms loosely, causing even more confusion.
Exactly. I'm trying to over simplify these concepts and build up slowly. I want this information to no longer be gate kept, but out in the open and UNDERSTANDABLE, as you know is difficult. Thanks sincerely for the support, friend. Means a lot
I love how quirky you are and so full of knowledge! Thanks for sharing these secrets :)
Absolutely awesome explanation. Great way to think about espresso. Too much focus on pressure without the fundamental understanding. Keep up the amazing videos!
Just applied some of this, had the best shot from a Barista Express yet, with slight but pleasant acidity, great sweetness, chocolate aftertaste that is lasting half an hour after the shot. You're a saviour! 😂
Lance, you are killing it man! Love the passion and knowledge that you bring in every video. From one of the first videos I saw early on, I knew this was a channel to help so many with their espresso skills. Quick favor man, the more recent videos lately have been a really deep dive into a PhD level of espresso. Do you have anything on tap for the undergrad espresso students in the class just trying to improve their day to day coffee/ shot making skills? Thank you Lance!!!
Yes! Definitely. I will be bouncing back and forth. I'm trying to hit as many people as possible! And this video, to be honest, though it might seem difficult, is important to understand!
Very informative, thanks! I have an e61 with flow control and pressure gauge on the group and was struggling to wrap my mind around using it in and effective way. This helps alot.
Awesome! I'm glad you found it useful! Hopefully you'll be ripping some delightfully extracted shots soon!
Thanks a lot, great explanation how to get the best result at any expresso machine. Is just a matter to adjust the finest grind to allow the machine give the highest amount of pressure .
that video on the exact week I received my E61 flow profil device... Might be a god after all
Very clear as always from You. Many thanks.
Great explanation! Somewhat advanced so it took some time to digest.
This w as so informative. Thank you so much for sharing this.
Love how you explain things!!👍😀❤️ thanks for this!
Very very informative. I really enjoyed it and I'll be back!
great great great great video lance
Killing it with the deepdives lately.
Thank you! Appreciate that, my friend. The support is massive
SUBSCRIBED AND LIKED! BEST COFFEE CHANNEL ON RUclips 🙌🏻
I enjoy the diversity of your videos, you are covering all the bases of coffee and every video is full of education, fun, and verbal excellence! Even when you cover a topic I may not be interested in I watch it anyway and learn something. Please keep up the great work.
Thank you so much! The support means so much to me. I appreciate deeply your kind words!
Great stuff. Thanks !!!
Hey, Lance - you're repetitive. But, I like it. Great, educational videos. Appreciate you sharing your knowledge. Thank you!
Haha thank you! The support is massive!
Some of us need all the repetition to get the idea in lol
Great job explaining a previously complex process!
Thank you so much! Appreciate it
One of the best coffee videos i've seen on RUclips. Nicely done Lance! Will you be able to help us understand how we can execute some of these principles on the Flair? My big learning is that the high stock pressure that comes on the machines is not really a dealbreaker at all if one is willing to put in the time to calibrate the grind. Looking forward to the gaggia video since im thinking of buying one!
amazing tutorial !
Great explanations. Thanks so much. There is one thing I am unsure if I can agree. Would be great to discuss this with the folks around here. I understood Lance as follows: Let's assume we measure different water debits under no pressure conditions and note the corresponding valve positions. Lance said when pressure builds and the pressure exceeds the set pressure of the OPV a part of the water will take the way over the by-pass via the OPV and the rest ends as espresso. The water debit measured under no pressure conditions stays the same, but being distributed between OPV and coffee puck. Example: Water debit measured under no flow conditions at specific valve position is 4 g/s and at 9 bar OPV setting, 3 g/s go via the OPV and 1 g/s goes through the coffee puck. I don't believe at 9 bar the water debit the pump can deliver will be the same as under no flow conditions, but will be lower. With increasing pressure, the flow rate (water debit) a pump can realize decreases. This typical behavior of a pump can be visualized with a pump curve correlating pressure and flow rate.
I agree that with pressures exceeding the max resistance of the OPV, the OPV opens and some of the water flow takes the by-pass and some go via the coffee puck. I only do not agree that the water debit as measured under no flow conditions is the same as at elevated pressure. What is your opinion on that?
Yes. Sure. If you have a super fine grind and set debit in a machine is 9ml/s, but only 2ml/s can make it through, I doubt sincerely 9ml/s will remain. I didn't see the need of diving into this when explaining a concept foreign to 99% of the populous. I ran this by a few engineers in home barista forums and got their thumbs up for a simplified explanation of these concepts. Cheers
Exceptional topic, Lance! This is exactly what I ve been looking for.
I will be happy if you admit, that 9 bar mashines require a coarser grind than 15 bar. So if I change my opv spring to 9 bar - I will gring beans coarser than before
A very confusing subject, thanks for making it easier to understand.
Great Vid.
Cheers Lance! Happy Friday!
Cheers, friend! And happy brewing!
Wow. Say that. Very very clear. Much clear
Fantastic Lance! Could there be a follow up video on how flow rates influence flavour clarity and body? From what I have experienced long slow flow rates increase clarity but sometimes at the expense of body?? I guess the question is how to manipulate flow to extract different flavours and varying degrees of body from the shot.
Lance, so with a coffee machine that doesn't have any flow control, eg. Breville/Sage Barista Express, should you use the grind size to set the max pressure (since the pressure will drop as the espresso flow naturally increases over time) and then tune finer/coarser for taste?
Grind size will ultimately effect the flow rate yes.
You can also modulate flow with your steam wand unless it’s a dual boiler set up
Great video Lance!! Is there a difference between adjusting the pressure and timing of the preinfusion on the BDB and using the slayer mod? Is it essentially doing the same thing but just at a fixed/lower water debit?
Great Vid on an important Topic.
Appreciate that a lot! Thanks
Wow! So I got a BIG question:
I have been profiling on my flair for long time thinking if I do 2 bars infusion, then 9 bars, then go slowly to 7 , that is profiling, but I didn't think about perfect grind size, means when I go to 9 bars should the grind be coarse enough to reach 9 then come back down? Bc if it is finer then it should, it will STILL go to 9 bars and go let, bc I'm controlling the force of the lever, BUT it will have a lower espresso flow, right?
So,
What is the range of good espresso flow then? If I want to do the slayer shot on my flair, 2 bars then 9 then down to 6 or 5, what flow does it need to stay at in each phase? After the infusion ramping up to 9, then start calculating the flow? And maintain that flow down to 6? What would be the flow rate that is adequate?
Also, is there a different way to calculate the flow intra shot without an acaia scale and Profiler app?
Thanks for the eye opener!
Short answer: Depends. Long answer: Depends on grind, desired yield, desired taste, grinder.
Amazing video! Would love to hear about dialing in the shot with the profile, as we could see here you had (of what I guess was a standard 18-19 modern espresso dose) an 45~50 grams of extraction so that's 2.7 ratio in about 40 seconds, how should I know what to expect? is the dial in just the same as the "regular" shot I pull? time is a major factor to know if I should go finer or coarser and here it's unknown because I'm not sure what to aim for
Another great video Lance. Thank you. So how would you replicate a slayer shot on the flair 58? Are you able to measure water debit on a manual machine or do you just measure espresso flow and call it close enough?
To my understanding, a device like Flair does not have any water input mechanism (i.e. a pump). Water moving through the puck relies completely on applied force/pressure. Hence I would assume that it is unnecessary to know or even measure "water debit".
Therefore, I would think it is only essential to record the pressure during the brew, as well as the output flow rate. These 2 extra parameters, along with the grind size of coffee and brew time, is all you would need to make adjustments to and achieve the ideal espresso you're aiming for.
To answer your question, replicating a slayer shot would be replicating the pressure profile + output flow profile. Slayer would control its input water by adjusting needle valve while Flair would do the same by adjusting applied force respectively. Hope this helps.
Great vid ! Its always kinda confuse me and still do a bit ....4g / second from the machine with opv set at 3bars wont give the same "espresso flow" as 4g / second from the machine with opv set at 9bars ? Or will it ? Because a lot more pressur will force that 4g per seconde out of the puck ? Which will result in a quicker espresso shot if i want 20in 40 out ? Or im my missing the whole point ?
I love that technology is unlocking a new frontier of espresso.
Quick question, if we are mostly concerned with flow-rate when profiling, then we really don't need any fancy pressure sensors anymore, correct? The simple pressure dials/sensors that come with most machines, (in additions to lets say an acaia lunar), should suffice for identifying any major grind/puck issues. Am I missing anything?
Been binge watching your videos...great info!! Have you had a chance to use any of the aftermarket flow controls for E61 machines? If so, do they do the job? thanks....
Lance, could you point me to some literature about the physics of espresso? I am really interested in the subject and would like to know more, but there is so many sources that it's almost impossible to filter the good ones from bad ones.
Thank you in advance, and keep the videos comming, I love them!
Hi Lance, could you please tell me what app you were using with the acaia scale to measure flow?
So from what I understand is that you input flow onto the coffee puck (ex. 4gps) and it doesnt necessarily mean that the espresso will hit 9 bars (depends on the grind size). If its too fine, the machine will have a higher bar pressure even if the valve isnt fully open
I have a machine with 15 bar pump pressure, and it doesn’t have the opv valve and flow control. So at the end of every shot, it will rise up to 15 bar and even more if i the ground is too fine. How do i do the hack thing to make a better shot?
the video is so genuine I genuinely liked the video when he asked to. I rarely likes video but this is just so much effort and thoughts to not be liked. :)
This was a great video. I am wondering and if you could do a video about volumetric dialling, which actually works with water debit vs espresso flow.
Brilliant as ever @Lance. Couple of thoughts. I have an ACS VESUVIUS and it's specifically a pressure profiling machine.. so pressure can be an input variable on some machines. More generally if you have a Lever machine aren't you effectively pressure profiling to achieve the flow profile you want? BW Graham
Great video, best friend. I understood water debit differently. I thought that if you had a 6g/s flow rate going in to the puck, and had a 4g/s into the cup, that your water debit would be 2g/s (also could be measured in weight a la 50 in, 36 out or something). So, what would we call that?
Another brilliant video 😊. Now, this might be sacrilegious, but if I distill everything down. Using the same coffee, grind, puck prep etc, the only real-time metric/device needed to reproduce a shot, is the app + Acaia? All other concepts, water debit, even pressure, are great but not essential. As long as you see the flow, you can adjust a dial, and get a similar shot? Pressures maybe be different per shot, but the flow is the same. Have I got that right? I ask, because I’m trying to budget for a new setup and there are so many choices.
Hey Lance,
On the DB with slayer mod, do I turn off the pre infusion which the machine is set up to do say 7 secondsetc.
I guess I then control the flow for pre infusion say 1.4ml a second, do I then turn the dial after this until I reach say 8bor 9 bars then slowly ramp down again from the puck degrading.
Thanks again for such great opportunities to improve coffee on your videos.
With the preinfusion, I wouldn't worry about the built in PI. I would measure water debit and profile based off supposed input flow until you have output flow, wherein you can guess after some extraction will equal roughly input.
I only truly understood this after buying my own Decent. There are only 5 input variables, two controlled by the espresso machine - temperature and flow, two controlled by the grinder - dose and grind. One, beans, controlled by the barista. Pressure is dependent on the interaction between dose, grind and flow
Yep, a little sad that lance forgot to mention dose weight as a factor
Hey @lancehedrick do you use the BDBs programmable PI or just the flow profiling?
I don’t know if you pay respond to questions about old videos. But if you do, I’m curious about how all this plays out with spring lever machines, such as my Londinium 1. Thanks.
Im still confused at how pressure relates to shot times for a given yield.
My issue is I've been playing around with 7 bar on the "pressure setting" or opv. So I doubt the normal ball park metrics of 20g coffee for 40g yield in 28 seconds works? my palate isn't super dialled in that I really know what I'm doing with dialling in at different pressures?
Do you have any tips for making espresso at lower pump pressures?
Great vid!. Wonder if acaia lunar + smart espresso profiler + blue tooth controlled manual switch could give you a gravimetric machine?
Hey Lance, so what’s the point of the bluetooth pressure sensor that goes with the espresso profiler app ? And you said that pressure was an input with lever machines, so in that case is it also un-necessary to use the pressure sensor/transmitter ? Thank you.
Really interesting, and totally makes sense. I guess you could think of pressure as analogous to impedance in a DC circuit. Funnily enough, I better understood electrical impedance with an explanation that compared it to water pressure ;)
Hello, Lance. I have a question about the Gaggia Classic Pro and using your dimmer suggestion to control flow for similar result to your work on the dual boiler in this video? Is that dimmer suggestion really providing a practical flow control? Thanks for any reply.
Yes! It's a more responsive flow control than the slayer mod in the Breville. It's quite incredible.
This makes so much sense man. I’ve been adjusting pressure on my flair but haven’t thought about flow rate but that makes a lot of sense.
Your explanation is always so clear and easy to understand.
I think if you started with metaphors in the beginning to give people some grounding would make it easier to understand (that Gandalf you shall not pass example was great)
You could also do comparisons where you have same flow rate but different pressure
And same pressure but different flow rate and compare tastes.
I’m gonna start doing that stuff on my channel
How can I adjust the water debit on the Breville Oracle Touch?
How did you modify your Breville dual boiler? With the smart profiler?
How are you able to move so much on the water knob on the BDB? The ones I've seen the ranges were a lot smaller
Subscribed and liked
What millimeter measuring strip do you have on your needle valve?
What does this mean for espresso machines like the Solis Perfetta where you can’t control the water debit? You only change the grind until it peaks at 9 bars?
Great video Lance.
Lots of variables here.
5kgs of coffee, 10 hours, sanremo and we might have some answers ;-)
I’ll email you this week. I’m off to Europe next week for a few weeks.
All the best,
Eric😀☕️
Hi Lance! Thanx a lot for this video!
Question - what about lever machines? What is there to play with regarding the topic? Thanx in advance. Your big fan. Lennard
I believe before even trying to experiment the flow control…. We need to find out the perfect grind size… so at what pressure (and other parameter) we need to experiment that?
Hey so I got the profitec pro 600 and haves flow control is that the same thing your doin as to dialing mine in with how much water goes through
Yes! I would recommend using the smart espresso profiler app with a bluetooth scale and tracking your flow. Will help you greatly in dialing in different styles of shots.
I enjoy you videos and I learned a lot of them. Thank you for that.
What are these two coffee machines in the video? Any recommendations or reviews on them as I’m planning to get a machine soon.
Left Breville or sage about 800$ usd
Right Decent I think but I'm not sure +2000$ usd
It is a good idea to focus on getting the best grinder you can afford first, then focus on a machine.
The better the grinder the more consistent the grinds will be.
Better does not always equal expensive. Also use quality water... Trust me the water used makes a HUGE difference.
I thought just filtered tap and I live in a country with great water but after I made brewing waters 1 for filter and 1 water for espresso the coffee I made popped like never before. Holy crap was I surprised. The fruitiness, the boldness the depth of coffee was soooo much better.
Please let me know if this helps and if I may ever be of assistance. If I do not know something, we can find the answer together.
I just want people to enjoy their coffee. Nothing else here. 😊😊
Can you share the weight of your shot at the point you raise and lower your flow so we can work on dialing in our grind size to match? Thanks!
you've convinced me to do the dimmer mod on my gaggia