Love this. A clear, bottomless portafilter should be where every espresso beginner starts. It takes all of the details to be right to get that perfect pour!
I think the point about tamping is situational. The distance between the puck and the shower screen is quite far comparing to the regular double or even triple basket (not to mention single on some machine). That distance means the water has more chance to build momentum and dig into the puck, and it can do it for longer (until the water fill the basket and become pressurized). This is not to say this video is bad. It's great actually. Pretty impressed seeing the reaction of the puck to pressure and gas. P/s: i mean the tamp dont need to be extra firm or light, but tamping to get the puck stay even through the extraction is always a good idea
Awesome work. De-mystifies the whole process. Shows what works and what doesn’t, shows also that what some believe might have been ‘channeling’ to be merely gas escaping. Also - though it does not show it explicitly - lets you know what occurs during pre-infusion.
I love this. Although lower so not identical to a normal portafilter, it makes the process visible and answers some questions I've seen debated on various forums. Gives a great insight to what's happening during the shot.
Wow that clears some myths up - like that the coffee swells at the beggining and when it does it touches the screen and causes uneven extraction- now we see that the swelling occurs when the extraction stops.
not exactly, it can swell at the beginning but it depends how you are preinfusing, if the shot goes directly into being under pressure then the puck is not allowed to swell like it would if it was preinfused without overhead pressure. (there should be the video of the lever too) Point is that people say that coffee does this and that and tend to assume thats valid for every machine in every condition when reality is that if you change what the machine does, the coffee reacts differently. And you shouldnt always do preinfusion for everything and everytime, depends on the coffee.
I believe what i see,i see good advice.This is what i would expect to see,with the firm and level tamp.This really is the best,i personally have found.Thanks for reinforcing,what i believe to.
yep, it matters a lot - quite not surprisingly. Basically, if the tamp is not level, water gets the quickest through the thinnest part of the puck and gets pressed straight down from that place. The flow from the portafilter then starts from that place, which is usually off-centric. If it starts there, then once water gets through the thickest parts, because of the affinity they'll join the primary flow, it will probably remain off-centric. I guess this might be one of the reasons to create convex tamper, but I will rather learn proper tamping technique than that, as in my mind I want my puck to be pressed with uniform pressure. Also, do you notice that even when it seems like proper extraction, you might get something like "tornado flow", which is thinner, sometimes messy - sometimes not even visible. Happens to me sometimes. I believe I liked the most the shots that looked almost like "milking the cow in slow motion". Great stuff, wonderful to finally see (to my disappointment), what's happening in the group head. Now it seems that espresso gets the oil character and crema on the border of pressure difference, quite boring in contrast to an idea that there is some magic happening in the group, but its physics :D Thank you! :)
Thanks Radim! I sometimes see what you call the 'tornado flow' when I use the little La Pavoni lever machine, which is less easy to handle than (for instance) my Londinium lever machine. Or it happens when part of the grinds are older, for instance in the early morning, a first shot from a grinder that has more retention. I do still think it's a remarkable metamorphosis, from a dry brittle puck to a flexible 'body' that receives water on one end end oozes out delicious espresso on the other end. ;-)
@@palefire definitely :-) I mostly work with Gaggia Classic (at work), it's pretty capable, but not really meant to make many drinks an hour. If you would be the third person in the queue, it would be noticeable, almost like the pump getting "exhausted". But when it's really ready, I'm pulling triple shots (20g) using naked portafilter and that's just porn... Thinking about buying ECM Synchronika to my home, especially now during the quarantine :-D
Wow, this is amazing! It would be really interesting to see the comparison with and without a metal puck screen on top, and/or a paper filter on the bottom.
Wow. You can see the process so well. The clear port a filter looks uneven at the base though. This makes the water pool at one end of the puck at the start of the shot. The he results look great nonetheless. Very educational.
First time I've seen this done clearly..please correct me if I'm wrong,it seems to me that espresso is just basically drip coffee with the difference of the coffee particles being finer and being compacted before the hot water dips down?
Thanks! It's a great question and some may hold different views than I have. In my observation, something remarkable happens in the basket under pressure. The hot water immerses the puck, air bubbles escape and also gas is expelled from the grinds and instead of a dry brittle compacted amount of unconnected grinds the puck transforms into a fexible unity which is able to slightly expand and shrink while basically remaining the same unified body that is infused with the hot water on one end while it oozes out espresso on the other end. At the bottom end, some gas / air that was compressed into the water, is coming out again as crema, enabled by the fatty substance from the grinds. Old beans and pre-ground coffee grinds that have completely de-gassed do not yield this crema in that quanity. Drip coffee on the other hand seems to change less spectacularly, as it rests in the filter, gets wet, 'blooms' and merely gets muddy. Light roasts can yield exquisite coffee this way, but I have not delved deeply into that brew method and cannot speak about it too much.
There's similarities, hot water is extracting the coffee solubles. The grind size, pressure, the speed (and scale: less coffee being extracted at once) of the extraction are very different. Also with drip the paper filter reduces oils and fine particles from the coffee.
There are many variables, which makes it all so much more interesting to think about. The pressure is a relative thing wherever you measure. For instance, at 9 bar in the tubing towards the brew group, the pressure just below the holes of the filterbasket is just the room / atmospheric pressure and the higher you'd measure in the puck, the higher the pressure reading will be. If one embeds a temperature probe inside the puck which I've done extensively, that reading also depends a lot on the exact placement of the probe, the type of probe (thin/thick, fast/slow), and the flow of the extraction. So not a single one of these observations is absolute. With lots of different angles and data, and even more thinking about it, one can get a better understanding of what's happening, adjust accordingly, and if it works, enjoy most delicious espresso ;-)
Really nice job 👍 some questions about this experiment : what is your conclusion about puck prep, in other words what do you recommend for a best puck preparation in order to obtain the best coffee taste. On the text on the video you mention xx gr , is it the qty of coffee in ? There is no indication about the force in kg applied with the tamper when you write low or firm tamp. This indication is important in your conclusion. Waiting to reading you. BR.
Thankyou Jean-Marc! Yes the g is the amount of dry coffee grinds. Tamping flat with mild force and a tamper that fits snugly is helpful. Tamping hard is counter productive as the puck then is harder to pre-infuse. Greetings, F
@@palefire thanks for the answer. Have you a idea of the snugly force to use on the tamper. I use a bravo tamper. But I have no idea on how to adjust the force and which value of force is correct. Any help on that is welcome 🤗
@@catalinjeanmarc the tamper should fit, not so tight that you pull out the puck like a cork when pulling away the tamper. Enough force to have a flat top of tge puck. A friendly but strict feel of pushing. No agressive feel. I never measured the kg force. This part is not to worry about too much. You notice if the pre infusion takes a looong time at 9 bar that you may have ground too fine or tamped too hard :-)
Hi Lmm, thanks for writing. Your idea may very well improve the extraction but I such a mesh would likely move the coffee puck observation farther away from what is actually happening in a regular brew head and the usual non-transparent portafilter situation.
Don't you think it would be closer to real life as in a normal situation, the shower screen would only be mm away from the puck rather than a cm or more as in the transparent PF?
The relatively long distance in the transparent PF is not optimal. I have played with a sort of 'thick shower screen' with holes in it a little above the puck but that did not work well either. Someday someone else will come with a very functional realistic transparent device. At Fracino they had one with internal lighting even but they did not document it with film. And so far such devices are short lived so the projects end somewhere on a shelf or in a drawer.
Fascinating. Thank you for your efforts. Maybe casting with clear acrylics one could make these. But the sudden temperature/pressure shock would require 3-5 times thickness for safety.
Thank you! Yes, with enough resources a robust device that sits higher in the brew group would be possible. I am sure that R&D departments of companies like Illy / Nespresso have done it but not shared the spectacular images so it's up to the little guys ;-)
@@palefire It seems to me that this would be a great application for that new transparent aluminum. dornob.com/transparent-aluminum-glass-like-see-through-metal/
They are not for sale - Tije made a couple for the purpose of the filming. I have seen some others in Instagram, like some looking really really slick, made in Asia, but as far as I know none actually came online for sale. One Seattle factory asked Tije to make one for their educational / training video material but it was too expensive, especially since one would still need tech staff at location to fix any leaks along the way because the different expand/shrink coefficent of the different materials (sealant, metal, plastic) creates leaks under the 9bar pressure and sudden high temperatures.
@@palefire thank you. that info is very helpful. If I find any transparent portafilters for sale, I'll share that info in the comments. Looking for a couple of those now.
Welding properly cut plexiglass to properly cut plexiglass shouldn't leak under 9bar but unfortunately no engineers have tried to solve this problem...
@@miniwarrior7 It's also the plexiglass part attached, sealed to the brass of the portfilter and the steel of the filter basket bottom. Each part material with its own measure of widening/shrinking when temperature peaks/drops. The sealant can keep up with this up to a point for a number of shots but not over a lot of shots. Others have also built such devices and some in Asia looked much nicer even but I have not seen them for sale as robust tools (yet).
I was pretty sure the coffee puck should touch the showerscreen.. In your case it doesn't seem to happen.. Also you probably get a very wet puck in the end..
In this lower extra 'portafilter' the shower screen is not playing along much. Yes, there's more water landing on the puck, so the after-shot happenings also do not reflect a real life situation in a closed off 'normal' portafilter.
Kristof B. On the current model Londinium-R it is easy to compare exact pre infusion pressure. Lighter beans need higher pressure for full bodied extraction, traditional Italian roast does fine at low pressure pre infusion.
3.5 bar machines are steam driven. The coffee is extracted too slowly. This results in burned tasting coffee that is under extracted. I used to have steam machine 3.5 bar. Not bad with plunger style coffee. You can pre infuse for 30 seconds after using the steaming function. Takes about 28 seconds to make a semi expresso. You won, t form crema at 3.5 bar. You need atleast 9 bar for that and the right temperature con trol.
Анатолий Сапаргельдыев Hi! Tije made just a few that we used for filming. It’s a lot of work and a device like that does not ‘live’ very long. He has not made any more, so none for sale. Best regards, Frans
These are really interesting. Do you still do this? Have you tried purposefully introducing defects into the puck, such as clumps, cracks, uneven distribution? Was interesting to see the one that cracked after pressure was released. I try to examine my pucks to see if I made any such errors, but it seems like a crack after extraction might not mean there was a crack during, and not evidence of channelling?
Thank you! When the last one of the transparent portafilters blew up we also had about everything we wanted so we went on to other things. So we did not experiment with other variables. What we learned is that a tamp should not be too firm because we want to immerse the dry puck and have it transform itself into this flexible body that aborbs more water on one side and oozes out delicious espresso on the other end. Good distribution of the grinds is important, clumps in grinds are not as bas as they seem. And a dry puck can look broken on the top because at the end, when the pressure above the puck is much less, the compressed air pockets can expand and 'pop' but by then the espresso in the cup has already found its way to the taste buds and no harm is done.
@@palefire regarding tamping pressure, FWIW, this study found no difference in the extraction when varying the pressure between 5kg to 20kg: socraticcoffee.com/2015/07/the-impact-of-tamping-pressure-on-espresso-extraction/
@@gregsullivan7408 Yes, (after distribution of grinds) a gentle level tamp is necessary and other tamping varieties are probably just trivial hocus pocus.
If it was made of plastic so it would change the taste, if made of glass it would not stand for pushing water for long time i think, but nice try to let see the extraction proceed. thanks🌷
No I dont think so. A light and flat tamp is helpful, but there is some swirling of grinds that does not cause problems, and once fully permeated with water, the puck is a rather flexible 'body' which can expand/compress and sit snug in the basket.
Yes some are clearly very un-even, and even distribution of the espresso and tamping are absolutely key to a good extraction so I would discard any of the tests with bad tamping like that altogether as failed tests. The way to narrow down variables is by having a very consistent tamping method, I'm told how hard isn't as important as it being as even as possible.
Gilleko slow motion. Het is een rocket giotto. Daar is op gevement wel een dubbele OPV in geplaatst zodat pre-infusie en extractie elk op een andere druk kunnen, maar ik weet niet meer of dat ten tijde van deze opname er reeds in zat.
They are not for sale - Tije made a couple for the purpose of the filming. I have seen some others in Instagram, like some looking really really slick, made in Asia, but as far as I know none actually came online for sale. One Seattle factory asked Tije to make one for their educational / training video material but it was too expensive, especially since one would still need tech staff at location to fix any leaks along the way because the different expand/shrink coefficent of the different materials (sealant, metal, plastic) creates leaks under the 9bar pressure and sudden high temperatures.
Khaled Zurikat thanks Khaled! The transparent portafilters were temporary products. A lot of work but very satisfying to observe what happens, even if the device would need repairs after a few shots and finally break complelely after a dozen shots. To my knowlegde no spouted ones have been made.
Frans Goddijn no, no... I mean the air gap between the coffee and the “dispenser” (I don’t know how to call it... language problems). I have an espresso machine and it keep it tight the entire process (no gap), even after I finish extracting. It never “swell” as I read someone saying it does after. I saw a bit of “turbulence” on the gap as it inject water, is that good when trying to do the best possible coffee (maybe a competition)? That gap was intentionally to prove there is no need to compress the coffee while it is extracting?... It was nice to see how the coffee soaked the water uniformly 👍🏻
@@albertomartin70 Ah yes the space between puck and shower screen. Often in 'real' life that space is smaller but here it allows one to better observe what happens. Even if the space is small, the spuck tends to swell but is also compacted by the extraction pressure. If one has a hand lever machine and pulls too hard on the lever, the puck is compacted so much that the flow is actually slower than with a less fierce pull. I found it interesting that the turbulence is not a problem and during pre-infusion the puck changes from a brittle pack into a flexible unit of substance that can endure a lot.
Great video Frans! Have you ever tried to calculate the velocity of the water as it wicks through the puck? Would be very interesting to see how much (if any) difference there is between grind sizes. A pity we couldn't see what was going on at the bottom of the basket during these shots!
Thanks! Yes it would be fun to study this further but it takes a lot of handiwork to get one transparent filter and keep it in operation. Also in this method there's more water than usual on top of it, so a one on one comparison with "real life" is not guaranteed. We might get back to it sometime in the future or others will take it a step further.
Thanks Oscar! Tije is currently working on other projects, one of them being a new and beautiful version of the small smart coffee roaster that Jan is building the controls for. So I don't expect a new iteration of the transparent portafilter. Greetings and happy December days!
+marioidrovorodri It's not easy. Get transparant material that can stand heat & pressure, find someone to use an existing portafilter to fix that to, think of a way to attach the bottom of a filter basket which you carefully sawed off. The sealant must resist enormous pressure, 9 bar or it will go POOF! and also the different temperature / volume values of the materials may not be too far different or a cool system, once heated, will fall apart. So you will need an experienced craftsman with a fine workshop. And even the best one will fall apart after a number of extractions so be careful not to hurt yourself. On the other hand, watching these clips is practically without any danger if you have a good chair.
Make one out of Sapphire Crystal like wrist watches have :)) Bet it costs a fortune or two though. Maybe Lux Crystal like Seiko's watches use would be a much better price and is non-toxic.
Thanks Steven for your observation! The image at 1:53 does not look bad at all to me but this device and the videos were aiming at best view rather than best taste ;-) Although the taste may have been subtly enhanced by the superglue / sealant keeping the device more or less i one piece as long as possible. I don't think we drank any of it.
I agree, it's something to think about. Those berries were hand picked, washed, dried, sorted, selected, packed, shipped, cleared, picked up, roasted, ground, all by experts using the best tools available. Using supermarket low quality beans was an option, but would yield a much different result than what we were trying to make visible. Drinking the extraction was an option, but the materials we used for sealant and transparency were not all 'food safe' so could cause different worries. In our experience, a device like this falls apart beyond repair after a maximum of a dozen shots and that's why we did out best to gain as much visual information as possible during that 'run'. If others learn from the videos and in result waste fewer beans, getting a best extraction with less experimentation, it might turn out to be a good strategy.
Hi. It's not a product that's for sale. The best option is to have someone nearby with a lathe and engineering skills to make one and have him/her fix the device in between sessons to keep it in working condition as long as possible. At the time that we first published these videos about the transparent portafilter some others also seemed to be producing similar devices and on Instagram an Asian guy even posted very impressive beautiful photos of one that had external metal 'braces' to keep the thing together but i never saw one like that for sale.
Someone needs to send James Hoffmann one of these
Yes please!!!
Definitely
Love this. A clear, bottomless portafilter should be where every espresso beginner starts. It takes all of the details to be right to get that perfect pour!
Thanks!
nice !!
seing is believing,
best video on coffee extraction and what REALLY happens!!
Thank you!
I know right? Who would've thought it gets wet
@@thefatmoop you live and learn!
I think the point about tamping is situational. The distance between the puck and the shower screen is quite far comparing to the regular double or even triple basket (not to mention single on some machine). That distance means the water has more chance to build momentum and dig into the puck, and it can do it for longer (until the water fill the basket and become pressurized). This is not to say this video is bad. It's great actually. Pretty impressed seeing the reaction of the puck to pressure and gas.
P/s: i mean the tamp dont need to be extra firm or light, but tamping to get the puck stay even through the extraction is always a good idea
Thanh Nam Nguyen thankyou! I agree about the dustance.
Awesome work. De-mystifies the whole process. Shows what works and what doesn’t, shows also that what some believe might have been ‘channeling’ to be merely gas escaping. Also - though it does not show it explicitly - lets you know what occurs during pre-infusion.
I never knew what actually happened before I saw this video. Thanks for making this video.
Thank you very much for your kind remark!
Ok now I want a transparent basket.
I love this.
Although lower so not identical to a normal portafilter, it makes the process visible and answers some questions I've seen debated on various forums.
Gives a great insight to what's happening during the shot.
Thanks!
This is great! Thanks for sharing, really illustrating
Thank you! 10 years later these clips still get views, great fun!
Perfect. Just what I was looking for to see what’s happening in there. 👍
Thanks!
Wow that clears some myths up - like that the coffee swells at the beggining and when it does it touches the screen and causes uneven extraction- now we see that the swelling occurs when the extraction stops.
Thanks!
Makes sense because why would something swell under pressure.
not exactly, it can swell at the beginning but it depends how you are preinfusing, if the shot goes directly into being under pressure then the puck is not allowed to swell like it would if it was preinfused without overhead pressure. (there should be the video of the lever too)
Point is that people say that coffee does this and that and tend to assume thats valid for every machine in every condition when reality is that if you change what the machine does, the coffee reacts differently. And you shouldnt always do preinfusion for everything and everytime, depends on the coffee.
I believe what i see,i see good advice.This is what i would expect to see,with the firm and level tamp.This really is the best,i personally have found.Thanks for reinforcing,what i believe to.
Thank you James!
yep, it matters a lot - quite not surprisingly. Basically, if the tamp is not level, water gets the quickest through the thinnest part of the puck and gets pressed straight down from that place. The flow from the portafilter then starts from that place, which is usually off-centric. If it starts there, then once water gets through the thickest parts, because of the affinity they'll join the primary flow, it will probably remain off-centric. I guess this might be one of the reasons to create convex tamper, but I will rather learn proper tamping technique than that, as in my mind I want my puck to be pressed with uniform pressure.
Also, do you notice that even when it seems like proper extraction, you might get something like "tornado flow", which is thinner, sometimes messy - sometimes not even visible. Happens to me sometimes. I believe I liked the most the shots that looked almost like "milking the cow in slow motion".
Great stuff, wonderful to finally see (to my disappointment), what's happening in the group head. Now it seems that espresso gets the oil character and crema on the border of pressure difference, quite boring in contrast to an idea that there is some magic happening in the group, but its physics :D Thank you! :)
Thanks Radim! I sometimes see what you call the 'tornado flow' when I use the little La Pavoni lever machine, which is less easy to handle than (for instance) my Londinium lever machine. Or it happens when part of the grinds are older, for instance in the early morning, a first shot from a grinder that has more retention. I do still think it's a remarkable metamorphosis, from a dry brittle puck to a flexible 'body' that receives water on one end end oozes out delicious espresso on the other end. ;-)
@@palefire definitely :-) I mostly work with Gaggia Classic (at work), it's pretty capable, but not really meant to make many drinks an hour. If you would be the third person in the queue, it would be noticeable, almost like the pump getting "exhausted". But when it's really ready, I'm pulling triple shots (20g) using naked portafilter and that's just porn... Thinking about buying ECM Synchronika to my home, especially now during the quarantine :-D
@@geuros Good quarantine therapy, planning the next machine ;-)
Wow, this is amazing! It would be really interesting to see the comparison with and without a metal puck screen on top, and/or a paper filter on the bottom.
Thankyou! We did this work nearly 10 years ago and I agree that more can be done. Hopefully a next 'generation' will do that!
Wow. You can see the process so well.
The clear port a filter looks uneven at the base though. This makes the water pool at one end of the puck at the start of the shot. The he results look great nonetheless. Very educational.
Thankyou very much!
Is there a paper filter at the bottom? What is that white line?
interesting question.... the vibe pump seems to be micro-"stroking" the puck...,wonder how that effects extraction vs a rotary pump
Thank you 🙏 so much...I can’t wait to show it to my son, he loves coffee ☕️ as well.
Thank you! Best wishes!!
Great Video. Thank you so much.
Thank YOU!
I want to buy one of this..... Perfect gift for my best friend who is in this job...
I do not know any of these for sale now, sorry!
@@palefire yea I know, I have searched all the internet for it 😂😂😂
First time I've seen this done clearly..please correct me if I'm wrong,it seems to me that espresso is just basically drip coffee with the difference of the coffee particles being finer and being compacted before the hot water dips down?
Thanks! It's a great question and some may hold different views than I have. In my observation, something remarkable happens in the basket under pressure. The hot water immerses the puck, air bubbles escape and also gas is expelled from the grinds and instead of a dry brittle compacted amount of unconnected grinds the puck transforms into a fexible unity which is able to slightly expand and shrink while basically remaining the same unified body that is infused with the hot water on one end while it oozes out espresso on the other end. At the bottom end, some gas / air that was compressed into the water, is coming out again as crema, enabled by the fatty substance from the grinds. Old beans and pre-ground coffee grinds that have completely de-gassed do not yield this crema in that quanity. Drip coffee on the other hand seems to change less spectacularly, as it rests in the filter, gets wet, 'blooms' and merely gets muddy. Light roasts can yield exquisite coffee this way, but I have not delved deeply into that brew method and cannot speak about it too much.
There's similarities, hot water is extracting the coffee solubles.
The grind size, pressure, the speed (and scale: less coffee being extracted at once) of the extraction are very different. Also with drip the paper filter reduces oils and fine particles from the coffee.
This videos makes me think that precision shower screens doesn't make any difference
I agree. A well cleaned shower screen is more effective than an expensive one.
interesting, but how can I be sure that the pressure is the one show in the video? and the coffee used, the granulation... are much unknown!
There are many variables, which makes it all so much more interesting to think about. The pressure is a relative thing wherever you measure. For instance, at 9 bar in the tubing towards the brew group, the pressure just below the holes of the filterbasket is just the room / atmospheric pressure and the higher you'd measure in the puck, the higher the pressure reading will be. If one embeds a temperature probe inside the puck which I've done extensively, that reading also depends a lot on the exact placement of the probe, the type of probe (thin/thick, fast/slow), and the flow of the extraction. So not a single one of these observations is absolute. With lots of different angles and data, and even more thinking about it, one can get a better understanding of what's happening, adjust accordingly, and if it works, enjoy most delicious espresso ;-)
@@palefire thanks for the reply!👍
@@nucupanzaru9609 Thank you!
Very cool, Frans. Exotic sports cars and espresso. You are a man of great taste. Literally :)
Thanks! It's my neighbour who has the spectacular car, but I enjoy the view ;-)
A better representation of a naked portafilter! :)
Thankyou David!
I wonder what was going on with Extraction 4 and 5?
Channeled
Really nice job 👍 some questions about this experiment : what is your conclusion about puck prep, in other words what do you recommend for a best puck preparation in order to obtain the best coffee taste. On the text on the video you mention xx gr , is it the qty of coffee in ? There is no indication about the force in kg applied with the tamper when you write low or firm tamp. This indication is important in your conclusion. Waiting to reading you. BR.
Thankyou Jean-Marc! Yes the g is the amount of dry coffee grinds. Tamping flat with mild force and a tamper that fits snugly is helpful. Tamping hard is counter productive as the puck then is harder to pre-infuse. Greetings, F
@@palefire thanks for the answer. Have you a idea of the snugly force to use on the tamper. I use a bravo tamper. But I have no idea on how to adjust the force and which value of force is correct. Any help on that is welcome 🤗
@@catalinjeanmarc the tamper should fit, not so tight that you pull out the puck like a cork when pulling away the tamper. Enough force to have a flat top of tge puck. A friendly but strict feel of pushing. No agressive feel. I never measured the kg force. This part is not to worry about too much. You notice if the pre infusion takes a looong time at 9 bar that you may have ground too fine or tamped too hard :-)
Frans, what would your thoughts on putting a fine mesh on the top of the bed of coffee to prevent damage of the surface from water droping on it?
Hi Lmm, thanks for writing. Your idea may very well improve the extraction but I such a mesh would likely move the coffee puck observation farther away from what is actually happening in a regular brew head and the usual non-transparent portafilter situation.
Don't you think it would be closer to real life as in a normal situation, the shower screen would only be mm away from the puck rather than a cm or more as in the transparent PF?
I thin this shows how absolutely essential it is to have perfectly level tamp?
The relatively long distance in the transparent PF is not optimal. I have played with a sort of 'thick shower screen' with holes in it a little above the puck but that did not work well either. Someday someone else will come with a very functional realistic transparent device. At Fracino they had one with internal lighting even but they did not document it with film. And so far such devices are short lived so the projects end somewhere on a shelf or in a drawer.
I agree that a level tamp is helpful.
so sloppy puck doesnt matter, it is just the coffee cant obsorb the leftover water?
@@reganstevenson9532 i think once wet, the puck becomes a different unit, flexible and like a (slightly soluble) sponge able to pass water.
Thank you very much for the informative video and the experimentation
thank you for your kind words!
Fascinating. Thank you for your efforts. Maybe casting with clear acrylics one could make these. But the sudden temperature/pressure shock would require 3-5 times thickness for safety.
Thank you! Yes, with enough resources a robust device that sits higher in the brew group would be possible. I am sure that R&D departments of companies like Illy / Nespresso have done it but not shared the spectacular images so it's up to the little guys ;-)
@@palefire It seems to me that this would be a great application for that new transparent aluminum. dornob.com/transparent-aluminum-glass-like-see-through-metal/
@@icowrich yes!
sorry, where can i buy one of those?
They are not for sale - Tije made a couple for the purpose of the filming. I have seen some others in Instagram, like some looking really really slick, made in Asia, but as far as I know none actually came online for sale. One Seattle factory asked Tije to make one for their educational / training video material but it was too expensive, especially since one would still need tech staff at location to fix any leaks along the way because the different expand/shrink coefficent of the different materials (sealant, metal, plastic) creates leaks under the 9bar pressure and sudden high temperatures.
@@palefire thank you.
that info is very helpful. If I find any transparent portafilters for sale, I'll share that info in the comments.
Looking for a couple of those now.
@@whiterogue1 best of luck! If you find a source I'm sure a number of people will be keen to get their hands on one as well.
Welding properly cut plexiglass to properly cut plexiglass shouldn't leak under 9bar but unfortunately no engineers have tried to solve this problem...
@@miniwarrior7 It's also the plexiglass part attached, sealed to the brass of the portfilter and the steel of the filter basket bottom. Each part material with its own measure of widening/shrinking when temperature peaks/drops. The sealant can keep up with this up to a point for a number of shots but not over a lot of shots. Others have also built such devices and some in Asia looked much nicer even but I have not seen them for sale as robust tools (yet).
I was pretty sure the coffee puck should touch the showerscreen.. In your case it doesn't seem to happen.. Also you probably get a very wet puck in the end..
In this lower extra 'portafilter' the shower screen is not playing along much. Yes, there's more water landing on the puck, so the after-shot happenings also do not reflect a real life situation in a closed off 'normal' portafilter.
@@palefire so this example doesn't match real world situations. Kinda sad.
topher ‘real world’ needs to be in quotation marks, to prevent sadness :-)
How was the coffee made with 4 bars? Is there a big difference? I’m asking because there are many 3,5-4 bar espresso machines out there.
Kristof B. On the current model Londinium-R it is easy to compare exact pre infusion pressure. Lighter beans need higher pressure for full bodied extraction, traditional Italian roast does fine at low pressure pre infusion.
3.5 bar machines are steam driven. The coffee is extracted too slowly. This results in burned tasting coffee that is under extracted. I used to have steam machine 3.5 bar. Not bad with plunger style coffee. You can pre infuse for 30 seconds after using the steaming function. Takes about 28 seconds to make a semi expresso. You won, t form crema at 3.5 bar. You need atleast 9 bar for that and the right temperature con trol.
Does it include preinfusion
Everything starts with preinfusion, one could say
Good afternoon, can you order such a holder from you?
Анатолий Сапаргельдыев Hi! Tije made just a few that we used for filming. It’s a lot of work and a device like that does not ‘live’ very long. He has not made any more, so none for sale. Best regards, Frans
Frans Goddijn Very sorry ) . Thanks for the answer !
These are really interesting. Do you still do this? Have you tried purposefully introducing defects into the puck, such as clumps, cracks, uneven distribution? Was interesting to see the one that cracked after pressure was released. I try to examine my pucks to see if I made any such errors, but it seems like a crack after extraction might not mean there was a crack during, and not evidence of channelling?
Thank you! When the last one of the transparent portafilters blew up we also had about everything we wanted so we went on to other things. So we did not experiment with other variables. What we learned is that a tamp should not be too firm because we want to immerse the dry puck and have it transform itself into this flexible body that aborbs more water on one side and oozes out delicious espresso on the other end. Good distribution of the grinds is important, clumps in grinds are not as bas as they seem. And a dry puck can look broken on the top because at the end, when the pressure above the puck is much less, the compressed air pockets can expand and 'pop' but by then the espresso in the cup has already found its way to the taste buds and no harm is done.
@@palefire regarding tamping pressure, FWIW, this study found no difference in the extraction when varying the pressure between 5kg to 20kg: socraticcoffee.com/2015/07/the-impact-of-tamping-pressure-on-espresso-extraction/
@@gregsullivan7408 Yes, (after distribution of grinds) a gentle level tamp is necessary and other tamping varieties are probably just trivial hocus pocus.
hello! we are desperately searching for a transparent portafilter, any idea where we cna buy it! thanks in adv
angie erdenetsogt hi! I have no idea who would have one or who is presently working on making these. Sorry!
If it was made of plastic so it would change the taste, if made of glass it would not stand for pushing water for long time i think, but nice try to let see the extraction proceed. thanks🌷
Thank you Mahmoud!
Does this prove that tamping is useless?!!
No I dont think so. A light and flat tamp is helpful, but there is some swirling of grinds that does not cause problems, and once fully permeated with water, the puck is a rather flexible 'body' which can expand/compress and sit snug in the basket.
Thanks for the video. But are some of the pucks uneven?
Yes some are clearly very un-even, and even distribution of the espresso and tamping are absolutely key to a good extraction so I would discard any of the tests with bad tamping like that altogether as failed tests. The way to narrow down variables is by having a very consistent tamping method, I'm told how hard isn't as important as it being as even as possible.
@@xbaxdark You're correct.
oddly satisfying
Yes ;-) there is no name for it yet.
@@palefire lol... I call it coffee porn or corn...
It was great to see this
Thank you!
Is dat een Rocket R58? Bijzondere drukopbouw in dat geval!
Gilleko slow motion. Het is een rocket giotto. Daar is op gevement wel een dubbele OPV in geplaatst zodat pre-infusie en extractie elk op een andere druk kunnen, maar ik weet niet meer of dat ten tijde van deze opname er reeds in zat.
Awesome for learning.
very interesting
Thanks
Where I can get this filter?
They are not for sale - Tije made a couple for the purpose of the filming. I have seen some others in Instagram, like some looking really really slick, made in Asia, but as far as I know none actually came online for sale. One Seattle factory asked Tije to make one for their educational / training video material but it was too expensive, especially since one would still need tech staff at location to fix any leaks along the way because the different expand/shrink coefficent of the different materials (sealant, metal, plastic) creates leaks under the 9bar pressure and sudden high temperatures.
What the puck?
Love it!
What coffee do you use?
Do they make these with spouts (58mm)?
Very cool video
Khaled Zurikat thanks Khaled! The transparent portafilters were temporary products. A lot of work but very satisfying to observe what happens, even if the device would need repairs after a few shots and finally break complelely after a dozen shots. To my knowlegde no spouted ones have been made.
The clear material is ...? Plastic or glass?
A R not glass. I should ask Tije who made it but if i remember correctly it was borosilicate.
PS correction! Tije explains it was acryl but polycarbonate would have been a possible alternative. So no borosilicate.
super information !
Thankyou!
This is very cool 😎🙌
1:46 Oh shit! Don't you hate it when you forget the cup!?
Yes!
Please 60FPS
Will keep it in mind if we ever produce one again.
@@palefire thank you
success, brother 🙂😊
Thank you!
That weird gap 🤔
Yes, a tool bounced against it and we kept it like that. Should have turned it away from the camera though ;-)
Frans Goddijn no, no... I mean the air gap between the coffee and the “dispenser” (I don’t know how to call it... language problems). I have an espresso machine and it keep it tight the entire process (no gap), even after I finish extracting. It never “swell” as I read someone saying it does after. I saw a bit of “turbulence” on the gap as it inject water, is that good when trying to do the best possible coffee (maybe a competition)? That gap was intentionally to prove there is no need to compress the coffee while it is extracting?... It was nice to see how the coffee soaked the water uniformly 👍🏻
@@albertomartin70 Ah yes the space between puck and shower screen. Often in 'real' life that space is smaller but here it allows one to better observe what happens. Even if the space is small, the spuck tends to swell but is also compacted by the extraction pressure. If one has a hand lever machine and pulls too hard on the lever, the puck is compacted so much that the flow is actually slower than with a less fierce pull. I found it interesting that the turbulence is not a problem and during pre-infusion the puck changes from a brittle pack into a flexible unit of substance that can endure a lot.
Great video Frans! Have you ever tried to calculate the velocity of the water as it wicks through the puck? Would be very interesting to see how much (if any) difference there is between grind sizes. A pity we couldn't see what was going on at the bottom of the basket during these shots!
Thanks! Yes it would be fun to study this further but it takes a lot of handiwork to get one transparent filter and keep it in operation. Also in this method there's more water than usual on top of it, so a one on one comparison with "real life" is not guaranteed. We might get back to it sometime in the future or others will take it a step further.
I'd like some of that coffee flavored goodness please
jeff medvin delicious stuff :-)
Can I have one to promote it in New Zealand? And you can start a business you never know.... all the best my friend. Greetings from NZ. Oscar.
Thanks Oscar! Tije is currently working on other projects, one of them being a new and beautiful version of the small smart coffee roaster that Jan is building the controls for. So I don't expect a new iteration of the transparent portafilter. Greetings and happy December days!
how can i make one of those portafilters?
+marioidrovorodri It's not easy. Get transparant material that can stand heat & pressure, find someone to use an existing portafilter to fix that to, think of a way to attach the bottom of a filter basket which you carefully sawed off. The sealant must resist enormous pressure, 9 bar or it will go POOF! and also the different temperature / volume values of the materials may not be too far different or a cool system, once heated, will fall apart. So you will need an experienced craftsman with a fine workshop. And even the best one will fall apart after a number of extractions so be careful not to hurt yourself. On the other hand, watching these clips is practically without any danger if you have a good chair.
material has to be non toxic
without BPA
Make one out of Sapphire Crystal like wrist watches have :)) Bet it costs a fortune or two though. Maybe Lux Crystal like Seiko's watches use would be a much better price and is non-toxic.
Que hermoso
Gracias!
Very uneven extractio. Must have been really sour
Thanks Steven for your observation! The image at 1:53 does not look bad at all to me but this device and the videos were aiming at best view rather than best taste ;-) Although the taste may have been subtly enhanced by the superglue / sealant keeping the device more or less i one piece as long as possible. I don't think we drank any of it.
😍😍😍😍 waowwww❤
Oh my god, did you just discard that espresso down to the drainage? What a waste man
I agree, it's something to think about. Those berries were hand picked, washed, dried, sorted, selected, packed, shipped, cleared, picked up, roasted, ground, all by experts using the best tools available. Using supermarket low quality beans was an option, but would yield a much different result than what we were trying to make visible. Drinking the extraction was an option, but the materials we used for sealant and transparency were not all 'food safe' so could cause different worries. In our experience, a device like this falls apart beyond repair after a maximum of a dozen shots and that's why we did out best to gain as much visual information as possible during that 'run'. If others learn from the videos and in result waste fewer beans, getting a best extraction with less experimentation, it might turn out to be a good strategy.
Angga Aditama “waste man” 😂😂
Give him your address a he can send in the mail
material must be non toxic without BPA (this can be harmful E.g. for pregnant women)
So much channeling...
impaque :-)
Where to buy it?
Hi. It's not a product that's for sale. The best option is to have someone nearby with a lathe and engineering skills to make one and have him/her fix the device in between sessons to keep it in working condition as long as possible. At the time that we first published these videos about the transparent portafilter some others also seemed to be producing similar devices and on Instagram an Asian guy even posted very impressive beautiful photos of one that had external metal 'braces' to keep the thing together but i never saw one like that for sale.