I’ve just watched this again for the manyth time and still learnt some things. Thank you for the amazing coffee learning resources on UA-cam Lance. So valuable.
I bought paper filters, went to a workshop with laser cutting machines. Tested a few and found perfect radius for both top and bottom of my 53mm portafilter. You should even consider they will expand when they get wet. I am really happy with the result and oh boy, they are satisfying when they match perfectly.
@@Arcadia1997 well, yes and no! Because you need to put the setting of the laser to fast and least power settings, otherwise the paper will burn. So i did 3 paper filters at once.
You can buy paper hole punchers online that do the same exact thing, I can’t link to mine here but you can search for EK Success 1.75-Inch Circle Punch for example. Perfectly fits the bottom of a 54mm basket
Just tried this by cutting some aeropress filters to fit my 53mm breville. I really do taste a difference! I have to grind finer now to achieve the right shot time, which is enhancing extraction. Thanks Lance and Jonathan, you guys rock!!
"You can't rely on optics" - this is precisely what I'm finding when it comes to channeling/extraction based on my own experience as a home barista using a naked portafilter. Btw, I've liked and subbed, good content, been going down the coffee rabbit-hole and I found your videos regarding the GCP and am enjoying your detailed analysis on all things coffee, cheers.
This was made for me... Got an Astrophysics masters, and did a presentation on the physics of coffee in my degree (as you can probably guess am obsessed!)
Hi Zac, what do you think of this theory of mine: I have been using paper filters at the bottom of my basket for some time now. I think the main reason it makes better extracted espresso is because it prevents channeling. How does it prevent channeling? If channelling starts to form in one place, the flow in the channel is limited by the paper filter. It just cannot increase, because the pores in the paper are just not big enough. As a result, the channel struggles to increase in size, to the point it just stays minimal, or non-existant. The paper filter acts as an element that limits local increases in pressure - it maintains the same pressure evenly across its surface, and thus across the puck. I actually have other theories about how to increase extraction for both filter coffee and espresso, but I’ll keep these for myself until I turn these into patented products :) I find the science of coffee to be full of grandmother myths that were perpetuated through word of mouth, but actually not always scientifically proven.
Just found this - awesome video, thanks Lance! It's interesting to listen to the the dynamics of how stacking puck screens affects the shot. I've always used two screens stacked to eliminate headspace - they just touch my shower screen (no screw), and I've found I prefer the flavour of this method. I did wonder for awhile whether preventing the expansion of the puck would increase the likelihood of channeling, but I haven't experienced it in practice. I also use a paper filter on the bottom AND between the screens to help evenly distribute that initial water flow, and keep my screens soaking in water between shots. I've been able to grind finer with all these layers as well, likely due to flow changes. I've ordered one of the newish slim screens that has a solid layer with large holes in it (like a shower screen), and interested to see if that changes anything. Would be interesting to see more data around headspace vs no, paper on top, and the use of multiple screens/types. Can't wait to hear more about Jonathan's work and research in future!
Such an outstanding video! I knew that paper filters helped reduce channeling (as experienced with my BEE), but this helps me understand even more why I am doing it and also helps me explain it to people who think I am crazy adding extra steps to maje espresso. Thank you Lance for bringing Jonathan on your channel! Keep it up good sir.
Thank you! Working with a new videographer and editor out here in portugal. This was all on one small fujifilm and a hand recorder. Shot while in Milan for world of coffee so didn't have much gear
Again very informative and data driven. I noticed that you guys were at BWT. I make using BWT a requirement for the cafe’s of which I contract and supply espresso machines. I’d love to see additional video presentations on water. Sorry for the topic diversion. It’s my OCD
I have a possible alternative hypothesis. Normally there are 2 resistors in series: the coffee grounds and the pf basket holes. Adding another resistor - the paper filter - can only increase the total resistance. Unless of course it affects one of the other resistors. The obvious candidate is the pf basket holes: now no longer partially blocked by semi soluble coffee grounds. So the added resistance of the paper filter is counteracted by an even greater reduction in pf resistance giving rise to a reduced overall resistance hence quicker flow rate. The increased extraction may be due to an upside down version of what Lance mentioned ie wetting of the puck - this time from below as the wicking effect of a paper filter is considerable. Would love to be able to experiment in this area. Thanks gentlemen for a thought provoking presentation!
This is interesting! Questions: which filters would be best (assuming we're going to cut them ourselves)? Also, near the end you guys were mentioning wetting the puck, should wetting the filter also be something we should do? Thanks!
Love things from a scientifically presented method I believe there are insights to be gained from a Materials Science/Engineering perspective (that's my degree, but don't look at me) as they're more involved with the chemistry of extraction and particles than most disciplines Talk to one IMO
Always enjoyable, fresh and well explained, even for beginners. I hope we don't need a thermonuclear expert for the next barista wave 🙂. Anyway, the Unifilter is intriguing, and to be "ego" , i remember a brief chat i had in Milan on 2015 with a guy directly involved with a coffee basket factory, i asked him why the coffee basket had not the holes covering the whole area of the bottom, vague answer, but probably it's difficult to do due to the mechanical stress, as you mentioned, during the shot, so i hope Mr. Weber, will think to produce a coffee basket with similar characteristic of the Unifilter portafilter. Great job Lance.
Re: the extraction decreasing as one moves from the puck center out to the edges. You probably don't want to change the hole size (tooling gets complicated), but you could decrease the hole spacing slightly as you moved from the center to the edge of the puck. That would tend to allow more flow and increase extraction towards the edges.
Yes tooling gets complicated changing hole size gradually moving out from centre, if manufacturing process stays with traditional and conventional stamping. There’re laser, etching etc, which is decades old ‘other’ industries have been using though. But then again, hole size variation has much to be limited by ground size. But density of number of holes (hole quantity per mmsq of real estate) could be a place to visit.
Lance, Could you do another video summarizing the effects of puck screen and bottom paper filter on channelling and extraction? Verbal narratives is quite difficult to follow.
Good news! I work directly with Gagne and Samo so there will be more and more here. I have worked in the coffee industry professionally for a decade and share insights with them and help collect data. This channel is steeped in it. I never set out to be an influencer lol
if the shot time of 25-30s is based on the conventional filter basket without filter which may include under extraction at the edges, shouldn't the shot time recommendation be re-adjusted for the cases with bottom filter and/or uni-filter?
Regarding the wetting of the puck screen, I have seen some data from Decent suggesting this is a good idea to improve the flow through the metal mesh, since the water is hydrophillic and the wetting will encourage flow. In principle this makes sense. However, I take this a step further -- I have noticed that there is a significant change in the temperature resulting from having a cold/room temperature moist puck screen. For this reason, when I heat my portafilter and cup with a blind shot, I also immerse the metal puck screen in there too. This ensures it's hot and wet when I place it into the filled basket and pull my shot, and this improves temperature control. It may be subjective but I notice a difference in taste. I bet you'd find there is a measurable difference in extraction yield. Not as much as a paper filter (I have issues with the paper waste, so I haven't used them), but still I'd bet money that the difference in distributions of extraction yield is significant.
I always insert the mesh into the group when heating the porta. So, I have not felt the need to do any tests. I do know there are tests showing the temp differential is inconsequential re: room temp or hot puck screen. Such small thermal mass. Anyway, I understand your stance on paper and respect it.
@@LanceHedrick I've got a Breville Barista Touch (the one with the very small thermoblock) and so in my experience it's been significant, perhaps because my machine is very sensitive to small variations in temperature and can swing wildly to correct. I'm not sure. The puck screen is about 35-40% of the mass of the portafilter basket, so with a bottomless portafilter that is a nontrivial amount of thermal mass. However, I think what you're saying is that my experience is unlikely to generalize, and that's totally fair. The beauty of science is that anecdotes can inform theories and hypotheses, but they don't necessarily prove out without an abundance of data from many sources. Thanks for the interesting discussion.
Yes- if you are only cpnsidering the basket in the thermal mass. You should take into account the surrounding bits as these have a massive impact on extraction and taste. So much so that Gagne and I have been preheating our unifilter over a boiling kettle. There have been users test the impact of the screen re: heat loss and have found it minimal. Curious what data you have seen that suggests otherwise?
@@LanceHedrick Just my own subjective taste from pulling a shot or two every day, trying my best to keep everything consistent. My test essentially is as follows; I warm the portafilter by pulling a 30-second blind shot (5 seconds of low pressure, 25 seconds of high pressure, I can't change this even if I wanted to) into my latte cup. The variable here is whether I put the screen into the cup or simply leave it out. I use the same coffee, predosed and measured, ground using the same grind setting on my Niche Zero. I use the same default temperature setting, which can vary a bit, so that's a problem. Regardless, what I observed was that the shot time to achieve 36g output from 18g input is slightly but consistently higher when the screen is cold/room temperature, by a margin of 1-2 or so seconds. However, there was a noticeable difference in taste. I don't have any plots of this as it's all been sparsely written down on paper. That said, there's likely to be a bunch of confounders here -- the machine just isn't super consistent from shot to shot and I'm not able to measure the temperature on the puck, just the output, and that's not super helpful. All I have is a theory and not much good data to back it, so I'm willing to concede that you're probably right that this doesn't generalize.
@@LanceHedrick Oh, sorry, a quick question. How do you go about preheating the unifilter? Do you immerse it in the boiling water in the kettle, pour it over, or something else? I can imagine that anything which ensures there's sufficient heat transfer into the thermal mass will do, so really any of these methods are equally valid, but then you have to dry it off afterwards prior to putting in the ground coffee. And the way you dry it off could potentially suck a lot of the heat out... another confounder for my experiment! Maybe I'm using a wet rag some days and a dry rag other days, and that would potentially explain the change better than the relatively small mass introduced by the puck screen! Espresso is such a fickle game... but I love it.
Love this video and the awesome insights it brings. I would appreciate seeing the error bars in the line graph-would help to show how significant “significant “ is. These differences could be meaningless if there is large variation within each condition.
wow, been doing puck screen and aeropress filter for about a year now and just aeropress filters for a couple years prior to that, it's nice to be validated with actual research
The Flair Signature has a somewhat concave filter-basket, so when you tamp the grounds flat on top, the water has a somewhat longer path through the grounds on its way to the middle of the bottom. The holes don’t go to the edge, but I think this is compensated by the concave bottom. The question, then, is “what’s the right amount of grounds to put in so that the concave bottom and the no-holes-at-the-edge balance each other?” I’m guessing it’s about 10g. This is similar to what Ross said, below: maybe a convex tamp would also compensate for a no-holes-at-the-edge filter.
Have been adding a paper filter to the top of my prismo for a long long time now. And have also put the paper on the bottom and plugged it during an early morning non awake coffee brew.
@@LanceHedrick I do have a bit of beard envy. Just finished the video. Great info. I had tried a paper filter in my robot basket a while ago but found cutting AeroPress filters into smaller circles tedious. Going to give it another go now and try and stick with it, redial in etc etc.
Always enjoy your videos...so much GREAT info. I had never imagined that the basket bends a bit under pressure. I am wondering if the video you did awhile ago concerning using a lower pressure setting also lessens the 'bend'. Currently looking into aftermarket flow control to see if that will accomplish the same thing. thanks again for all work on our behalf...
I did not hear comments about how using the paper requires the grind to be much, much finer in order for the shot to pull within the regular 25-30 second window. This is a great benefit in terms of extraction.
@@LanceHedrick while this is true it might be confusing for someone trying it for the first time as the shot will pull fast enough to think you messed up. I think it’s worth a quick mention
Hi Lance, very nice video, as always. I'm just going through your older videos and discovered this one. Quick question: do you know if there's any testing of a puck screen with a paper filter on top of the puck? One paper filter on the bottom, one on top and a puck screen over all this.
I use filter paper at the bottom of the puck for most of my espresso shots, particularly with lighter roasts. In my experience the weave of the paper matters a great deal. I use 55mm Whatman laboratory papers with 15g VST baskets. The three I use are Number 1 which has a pore size of 11 microns; Number 4, pore size 25 microns; and Number 5; pore size 2.5 microns. Number 4 is the fastest, Number 5 the slowest; and number 1somewhere between them. The difference in flow rate between Numbers 4 and 5 is great, and so is the consequent differences in flavour.
Yup. Correct. I have a few whatman, but don't use the only because they arent food grade (I know they aren't harmful, but the majority seem scared if not FDA approved). Grade 5 is fun, but there is a weird aftertaste with it that I, Rao, and a few others have noticed.
Paper filters of the correct size are more available (June 2023) , would using a paper filter on top of the puck (as well as the bottom)instead of a metal filter work? Would it help to reduce residue going into the solenoid backwash? I have read people complain that keeping the metal filter clean is an additional chore and they don’t like digging it out of the knock box. SG
What about using a paper filter on top as well as the bottom instead of a puck screen ? Does that do the same thing as the puck screen keeping it clean?
Very interesting Lance. I had no idea we Canadians were pushing the frontiers of coffee. I live in Waterloo -just a few blocks from the perimeter institute for advanced physics (Steven Hawking used to spend some time there), I wonder if I could get them interested in abandoning their search for quarks, black holes etc. and switch to coffee. Coffee research is certainly more relevant to my life than that other physics stuff 😄On that portafilter though, $495 (that's Canadian, but still), for a portafilter!!!!!!! I sure hope someone else starts producing these better portafilters at a price that isn't, out of this world!!!
Wow, I love vids like this one! As a Flair Classic user I can't wait to try a filter to see if it helps improve the uniformity of flow in my shots. I'm mostly a V60 guy but I do break out the Flair occasionally and lately it seems like my puck prep has gone to hell. I'm getting splatters and spurts like crazy and I'm doing exactly (near as I can tell) the same puck prep (WDT and tamp). I've not observed anything as dramatic as the photos you showed when examining my pucks but I do see different shades and assumed it was a sign of uneven extraction. It seems that the name of the game is "uniformity of flow". Of course that makes sense but how to get there has been the 'rub' as it were...
If you are going to use a puck screen, do try having it hot and wet (filled with hot water) when you place it on the puck. I have refined this technique over quite a long time as it has nuances. Of course, if you are emulating a Londinium machine extraction with a Flair 58, then the issue of the shower screen is not there at all (for either machine). There was a guy that built a portafilter out of transparent material and you could see what happened to the puck under different scenarios which helps to understand what the screen, (as well as how the extraction is initiated) affects.
Yes I've seen the transparent PF. Issues with that are the walls have much less friction than a metal basket so can't really say it replicates it 1:1. Many have been doing puck screen heated and wet for a long time. This is just a video discussing what we do know objectively, not anecdotally, which is what has been splayed online for forever. A step in the direction of objectivity
@@LanceHedrick The transparent portafilter shows you what happens at the top of the coffee bed which is useful information but has little to do with the surface viscosity at the side of the basket. I agree that the transparent portafilter is useless for drawing conclusions based upon any extraction it performs for many reasons. The video has no speculation or referenced experiment that I take exception to. It was claiming that being an astrophysicist gave validity that attracted me to watch this video and was pleased at the quality of Jonathan's presentation.
I've tried using a puck screen but it was a mess (fishing it out from the spent puck is no fun). Have you measured the impact on brew temperature of having this chunk of metal in the mix? Are we supposed to pre-heat the puck screen between shots?
Very interesting 👍 I ordered a Pullman 17-19 gram basket and Good Brothers Coffee puck filters to replace my BDB stock one without filter. Can’t wait to try out. So if I understand correctly if i change nothing other than basket and add filter paper my flow rate will be faster? So if it takes 30 seconds currently to achieve 36g out I will have to grind finer to maintain same time?
I've seen it twice. Very informative. Thanks Lance and Johnathan 👏 however I think it would be better to discuss how we should pour water on to the Flair brew chamber in order to maintain consistency. Or maybe it doesn't affect the puck at all, but it would be better to mention it. By pouring water I mean w/o any other stuff but kettle
Sorry but not really. All flair 58 users use a puck screen but that doesn't mean most people using them are flair users. It's a bit like saying cows eat grass so if an animal eats grass it's a cow. Puck screens are used widely in espresso communities. As a flair 58 owner I would say we are in a small minority of the total puck screen users.
Lance you are not only a good barista, but a good journalist also I wanted to ask about the puck screens Do you thing that they drop the temperature of water before hitting the puck?
I used to ask why they put cloth atop the mouth of someone they torture via "water ingestion" (i guess) in movies. Is it safe to say that placing a paper filter on the bottom of the puck is the same concept?
would wetting the entire paper filter before placing it in the puck be a good idea? You seemed to suggest wetting the screen might help. Does that apply to the paper filter as well?
My pucks seem to layer into 2 or 3 parts and sometimes within the layer, I see very dark areas. I have tried almost everything to fix my channeling issue and starting to think about getting a duomo the eight even though it is so expensive. I have a baratza sette 270 wi and might upgrade to a niche or eureka also.
Can you clarify a bit more at the very end of the video when you discussed the expansion of the puck and the puck screen hitting the shower screen/screw? Other than the physical damage to the puck screen becoming indented by the screw, is this preferable in terms of shot extraction/taste by preventing the expansion of the puck and "having the same effect as a spacer"? Or should we aim to under-dose the puck to provide room for the puck screen to be lifted up and so it does not interfere with "the dynamics of the shot"?
My Normcore 58mm 1.7mm screen had a clear indent from my Rancilio Silvia v6 running an IMS 18g basket with 18.3g of medium roast. I just figured it was part of the process. I'm definitely going to have to try the filter paper in the bottom of the portafilter now.
Gonna try the filter paper on the bottom of the basket tomorrow. Shouldn't I expect to get less body though since I'm now basically making paper-filtered espresso? Curious to see if I'll lose all the tiger striping too. Thanks for the knowledge as always, Lance!
I don't think you really lose any. The theory that oils are held back by that tiny paper filter under that much pressure is unfounded, imo. Have not noticed that with shots over .5 bar.
These guys always test with top tier equipment, I'd be curious to see them test with lower tier machines that have subpar shower screens or other imperfections
I would think that if you put the puck screen inside the portafilter basket, and pulled a little water through (like when you preheat the basket/clean it out), then that would also help to “pre-wet” the puck screen as well. ((I do this when I preheat my Picopresso- I put the puck screen in the empty basket so that I preheat/wet everything))
Very interesting! I would love some more content like that, with this kind of guests. Two questions: Does a filter up of the pack make any difference? Does it work like a puck screen or its useless? Do you have to wet your filter before putting in on your basket? Is it necessary or harmful for your extraction?
I am not sure I understand "does a filter up of the pack" means. Let me know! And I do wet the paper filter with the steam wand and then wipe the sides of the basket dry
@@ElectTheChopStick I'd like to know this as well! I'm using filter paper both under and on coffee puck - latter mainly because it's easier to remove puck screen after the brew and I guess water could spread more evenly on the puck. Anyway, I get really dry pucks and clean filter basket after each brew and I'm using low end machine (BBE) so it's matter of workflow as well.
It would be awesome if you did a video on putting the filter paper on top of the puck verses on the bottom of the portafilter. I would love to know the difference it makes in extraction, If any. Also, would it be redundant to do both?
I don't care that puck screens don't improve extractions. The most important thing to me in home espresso when considering a new product after flavor is workflow and maintenance. As mentioned in the vifro, this screen has extended the time in between cleaning my shower screen by so much that I don't even worry about a dirty screen anymore affecting flavor and flow rate.
Exactly what Gagne and I said in the video. We both use them. There has been a lot of speculation as to some sort of majestic quality they hold that hasn't been noticed in Data collection.
I am wandering, can a paper filter on top of the puck replace the mesh screen in the same way ? Since I added a spacer to my DE1, I can’t use a mesh screen on top anymore…
If the sides don't extract as much as the center, doesn't this mean that having a non-WDT or distributed shot, where the center of the puck is more dense than the side, can help counter this difference in extraction?
I believe we hit the purpose in the video, but I'll reiterate here. The biggest thing is consistency. There is an increase and improvement in extraction, which directly correlates with flavors a la balance and depth of flavors, but you'll have less waste with more consistency
My wife has been using hand cut paper filters on the bottom of the filter basket for years and years, but hasn’t communicated this to anyone but me. She now says she deserves to get the Nobel price for that, LOL. One thing about the bending of the bottom of the filter basket due to the pressure exerted during extraction that seems rather positive to me, is the fact that coalescence of the stream prevents unnecessary temperature drop of the espresso on its way to the coffee cup. Would you agree on that, Lance?
Does the water flow resistance discussion apply to pre wetting the paper filter as well? It seems like pre wetting could help it stick when using a dosing cup?
I've been using a puck screen for over a year with my Flair 58. I do notice a faster flow after a deep clean, so how do the oils that remain inside the puck screen influence things? It's fairly stable shot-to-shot so it feels like the amount of 'stuff' gets exchanged with every shot. Maybe that's why wetting makes a difference ?
Using a 1.5 inch hole puncher to make perfectly sized filters for my 54mm basket rn. Also thought about using a compass and cutting manually but thats too much work.
Hi Lance, I commented on one of your other videos that was more relevant to this topic. But I am wondering if you have any recommendations for steam pitchers, specifically just for steaming. (I am using the Slow Pour round tip pitcher for latte art.) It would be nice to have a small and large steam pitcher for different size drinks, but it is not necessary. I was not sure which pitcher you would recommend and if you would recommend using a glass steam pitcher. I would really appreciate your guidance. Thank you!
Please hit that subscribe if you haven't! Almost at 100k!
Releasing a coffee video with an astrophysicist on the biggest Astronomy news day in over a decade is a good use of the algorithm.
Haha there was definitely a bit of planning. Though most was serendipitous
I’ve just watched this again for the manyth time and still learnt some things. Thank you for the amazing coffee learning resources on UA-cam Lance. So valuable.
fantastic! So happy you are finding my content helpful. Cheers!
I bought paper filters, went to a workshop with laser cutting machines. Tested a few and found perfect radius for both top and bottom of my 53mm portafilter. You should even consider they will expand when they get wet.
I am really happy with the result and oh boy, they are satisfying when they match perfectly.
How did you cut them? Can you stack the paper filters and cut them all at once?
@@Arcadia1997 well, yes and no!
Because you need to put the setting of the laser to fast and least power settings, otherwise the paper will burn. So i did 3 paper filters at once.
@@ashkanpower That's still much better than cutting one layer at a time. Thanks!!
That's awesome! Thanks for sharing
You can buy paper hole punchers online that do the same exact thing, I can’t link to mine here but you can search for EK Success 1.75-Inch Circle Punch for example. Perfectly fits the bottom of a 54mm basket
Just tried this by cutting some aeropress filters to fit my 53mm breville. I really do taste a difference! I have to grind finer now to achieve the right shot time, which is enhancing extraction. Thanks Lance and Jonathan, you guys rock!!
"You can't rely on optics" - this is precisely what I'm finding when it comes to channeling/extraction based on my own experience as a home barista using a naked portafilter.
Btw, I've liked and subbed, good content, been going down the coffee rabbit-hole and I found your videos regarding the GCP and am enjoying your detailed analysis on all things coffee, cheers.
Thank you! So glad you are enjoying it and I appreciate the support!
This was made for me... Got an Astrophysics masters, and did a presentation on the physics of coffee in my degree (as you can probably guess am obsessed!)
Love that! Hopefully more with Gagne in the future
@@LanceHedrick I’d love to see more videos on the science of espresso! I did mine in 2014 and our knowledge has majorly improved since!
@@LanceHedrick I’d love to see more videos on the science of espresso! I did mine in 2014 and our knowledge has majorly improved since!
Absolutely will! I always drop some science in my videos, but will try to do some more totally focused on it
Hi Zac, what do you think of this theory of mine: I have been using paper filters at the bottom of my basket for some time now. I think the main reason it makes better extracted espresso is because it prevents channeling. How does it prevent channeling? If channelling starts to form in one place, the flow in the channel is limited by the paper filter. It just cannot increase, because the pores in the paper are just not big enough. As a result, the channel struggles to increase in size, to the point it just stays minimal, or non-existant. The paper filter acts as an element that limits local increases in pressure - it maintains the same pressure evenly across its surface, and thus across the puck.
I actually have other theories about how to increase extraction for both filter coffee and espresso, but I’ll keep these for myself until I turn these into patented products :)
I find the science of coffee to be full of grandmother myths that were perpetuated through word of mouth, but actually not always scientifically proven.
You’re about to smash past *100k subscribers* at any moment now! 👏🏻
Thank you! Excited
1:50: so THAT is what PearlJam were singing about in Even Flow!
5:09 positively love this stuff. Thank you for doing science based culinary journalism in the tradition of Adam Ragusea!
What an incredibly insightful video, brilliant both of you!
Thank you!
Such a cool video! I am so glad Jonathan finally made a video appearance. Congrats on the scoop!
Agreed! Glad he was willing to jump on!
Thank you!
I see a lot of potencial grow in filter basket design; it’s an under thought piece of equipment.
Agreed
Just found this - awesome video, thanks Lance! It's interesting to listen to the the dynamics of how stacking puck screens affects the shot. I've always used two screens stacked to eliminate headspace - they just touch my shower screen (no screw), and I've found I prefer the flavour of this method. I did wonder for awhile whether preventing the expansion of the puck would increase the likelihood of channeling, but I haven't experienced it in practice. I also use a paper filter on the bottom AND between the screens to help evenly distribute that initial water flow, and keep my screens soaking in water between shots. I've been able to grind finer with all these layers as well, likely due to flow changes. I've ordered one of the newish slim screens that has a solid layer with large holes in it (like a shower screen), and interested to see if that changes anything. Would be interesting to see more data around headspace vs no, paper on top, and the use of multiple screens/types. Can't wait to hear more about Jonathan's work and research in future!
Been using paper filters for a few months, great to know why it works so well!
For sure! Evens that extraction
Do you wet the filters or put them in dry any flavor difference noticed?
@@IconicSeasons I usually wet them a little so they stay in place while i wdt. I've not done head to head tests or anything to see the difference.
Not as much taste difference as there is a potential increase in consistency since you negate gaps where you might have water wanting to flow
Can you please provide your source for these papers?
Such an outstanding video! I knew that paper filters helped reduce channeling (as experienced with my BEE), but this helps me understand even more why I am doing it and also helps me explain it to people who think I am crazy adding extra steps to maje espresso. Thank you Lance for bringing Jonathan on your channel! Keep it up good sir.
This was delightful! Thank you!
Brilliant thank you both. ❤️ ☕️ and thank you for the snap shots of findings through out. Keep up the good work.
Thank you! Working with a new videographer and editor out here in portugal. This was all on one small fujifilm and a hand recorder. Shot while in Milan for world of coffee so didn't have much gear
Congrats to the 100.000 subs!! Well deserved, really enjoying your vids! 😊
Again very informative and data driven. I noticed that you guys were at BWT. I make using BWT a requirement for the cafe’s of which I contract and supply espresso machines. I’d love to see additional video presentations on water. Sorry for the topic diversion. It’s my OCD
I have a possible alternative hypothesis. Normally there are 2 resistors in series: the coffee grounds and the pf basket holes. Adding another resistor - the paper filter - can only increase the total resistance. Unless of course it affects one of the other resistors. The obvious candidate is the pf basket holes: now no longer partially blocked by semi soluble coffee grounds. So the added resistance of the paper filter is counteracted by an even greater reduction in pf resistance giving rise to a reduced overall resistance hence quicker flow rate. The increased extraction may be due to an upside down version of what Lance mentioned ie wetting of the puck - this time from below as the wicking effect of a paper filter is considerable. Would love to be able to experiment in this area. Thanks gentlemen for a thought provoking presentation!
Filters are intentionally porous right? Wouldn't that decrease resistance?
@@teknophyle1 You're adding something in between that wasn't there before, so I would also say resistance increases.
This is interesting! Questions: which filters would be best (assuming we're going to cut them ourselves)? Also, near the end you guys were mentioning wetting the puck, should wetting the filter also be something we should do? Thanks!
I'm thinking wetting the filter will help it stay in place, but maybe that's not a problem with a properly fitted paper
Love things from a scientifically presented method
I believe there are insights to be gained from a Materials Science/Engineering perspective (that's my degree, but don't look at me) as they're more involved with the chemistry of extraction and particles than most disciplines
Talk to one IMO
Love how your facial hair is complementary: moustache on Lance, chinstrap on Jonathan!
Always enjoyable, fresh and well explained, even for beginners. I hope we don't need a thermonuclear expert for the next barista wave 🙂. Anyway, the Unifilter is intriguing, and to be "ego" , i remember a brief chat i had in Milan on 2015 with a guy directly involved with a coffee basket factory, i asked him why the coffee basket had not the holes covering the whole area of the bottom, vague answer, but probably it's difficult to do due to the mechanical stress, as you mentioned, during the shot, so i hope Mr. Weber, will think to produce a coffee basket with similar characteristic of the Unifilter portafilter. Great job Lance.
Yes. I've had chats with basket manufacturers over the years. One even agreed to make me one but never followed through. Thanks for watching!
Re: the extraction decreasing as one moves from the puck center out to the edges. You probably don't want to change the hole size (tooling gets complicated), but you could decrease the hole spacing slightly as you moved from the center to the edge of the puck. That would tend to allow more flow and increase extraction towards the edges.
Yes tooling gets complicated changing hole size gradually moving out from centre, if manufacturing process stays with traditional and conventional stamping.
There’re laser, etching etc, which is decades old ‘other’ industries have been using though.
But then again, hole size variation has much to be limited by ground size.
But density of number of holes (hole quantity per mmsq of real estate) could be a place to visit.
Lance,
Could you do another video summarizing the effects of puck screen and bottom paper filter on channelling and extraction? Verbal narratives is quite difficult to follow.
I just tried it as in 2 minutes ago using aeropress filter on sanremo 58mm naked portafilter. Trimmed it a bit to fit. It was amazing💙
Love to see the voices on the cutting edge of the research being elevated. This is something “coffee influencers” aren’t doing enough of.
Good news! I work directly with Gagne and Samo so there will be more and more here. I have worked in the coffee industry professionally for a decade and share insights with them and help collect data. This channel is steeped in it. I never set out to be an influencer lol
if the shot time of 25-30s is based on the conventional filter basket without filter which may include under extraction at the edges, shouldn't the shot time recommendation be re-adjusted for the cases with bottom filter and/or uni-filter?
Regarding the wetting of the puck screen, I have seen some data from Decent suggesting this is a good idea to improve the flow through the metal mesh, since the water is hydrophillic and the wetting will encourage flow. In principle this makes sense. However, I take this a step further -- I have noticed that there is a significant change in the temperature resulting from having a cold/room temperature moist puck screen. For this reason, when I heat my portafilter and cup with a blind shot, I also immerse the metal puck screen in there too. This ensures it's hot and wet when I place it into the filled basket and pull my shot, and this improves temperature control. It may be subjective but I notice a difference in taste. I bet you'd find there is a measurable difference in extraction yield. Not as much as a paper filter (I have issues with the paper waste, so I haven't used them), but still I'd bet money that the difference in distributions of extraction yield is significant.
I always insert the mesh into the group when heating the porta. So, I have not felt the need to do any tests. I do know there are tests showing the temp differential is inconsequential re: room temp or hot puck screen. Such small thermal mass. Anyway, I understand your stance on paper and respect it.
@@LanceHedrick I've got a Breville Barista Touch (the one with the very small thermoblock) and so in my experience it's been significant, perhaps because my machine is very sensitive to small variations in temperature and can swing wildly to correct. I'm not sure. The puck screen is about 35-40% of the mass of the portafilter basket, so with a bottomless portafilter that is a nontrivial amount of thermal mass. However, I think what you're saying is that my experience is unlikely to generalize, and that's totally fair. The beauty of science is that anecdotes can inform theories and hypotheses, but they don't necessarily prove out without an abundance of data from many sources. Thanks for the interesting discussion.
Yes- if you are only cpnsidering the basket in the thermal mass. You should take into account the surrounding bits as these have a massive impact on extraction and taste. So much so that Gagne and I have been preheating our unifilter over a boiling kettle. There have been users test the impact of the screen re: heat loss and have found it minimal. Curious what data you have seen that suggests otherwise?
@@LanceHedrick Just my own subjective taste from pulling a shot or two every day, trying my best to keep everything consistent. My test essentially is as follows; I warm the portafilter by pulling a 30-second blind shot (5 seconds of low pressure, 25 seconds of high pressure, I can't change this even if I wanted to) into my latte cup. The variable here is whether I put the screen into the cup or simply leave it out. I use the same coffee, predosed and measured, ground using the same grind setting on my Niche Zero. I use the same default temperature setting, which can vary a bit, so that's a problem. Regardless, what I observed was that the shot time to achieve 36g output from 18g input is slightly but consistently higher when the screen is cold/room temperature, by a margin of 1-2 or so seconds. However, there was a noticeable difference in taste. I don't have any plots of this as it's all been sparsely written down on paper. That said, there's likely to be a bunch of confounders here -- the machine just isn't super consistent from shot to shot and I'm not able to measure the temperature on the puck, just the output, and that's not super helpful. All I have is a theory and not much good data to back it, so I'm willing to concede that you're probably right that this doesn't generalize.
@@LanceHedrick Oh, sorry, a quick question. How do you go about preheating the unifilter? Do you immerse it in the boiling water in the kettle, pour it over, or something else? I can imagine that anything which ensures there's sufficient heat transfer into the thermal mass will do, so really any of these methods are equally valid, but then you have to dry it off afterwards prior to putting in the ground coffee. And the way you dry it off could potentially suck a lot of the heat out... another confounder for my experiment! Maybe I'm using a wet rag some days and a dry rag other days, and that would potentially explain the change better than the relatively small mass introduced by the puck screen! Espresso is such a fickle game... but I love it.
I didn’t know it was possible to steal someone else’s mustache 😂😂😂
Love this video and the awesome insights it brings. I would appreciate seeing the error bars in the line graph-would help to show how significant “significant “ is. These differences could be meaningless if there is large variation within each condition.
Ah yes. Makes sense.
Very informative!! Great video Lance…
Thank you!
I absolutely love this, thanks for sharing! I have to pick up a copy of Jonathan's book.
You definitely do. Link below
Some of this data is really hard to wrap your head around but very fascinating!
wow, been doing puck screen and aeropress filter for about a year now and just aeropress filters for a couple years prior to that, it's nice to be validated with actual research
Haha for sure! That's great
Could a puck screen be used on the bottom of the portafilter instead of a paper filter?
The Flair Signature has a somewhat concave filter-basket, so when you tamp the grounds flat on top, the water has a somewhat longer path through the grounds on its way to the middle of the bottom. The holes don’t go to the edge, but I think this is compensated by the concave bottom.
The question, then, is “what’s the right amount of grounds to put in so that the concave bottom and the no-holes-at-the-edge balance each other?” I’m guessing it’s about 10g.
This is similar to what Ross said, below: maybe a convex tamp would also compensate for a no-holes-at-the-edge filter.
Have been adding a paper filter to the top of my prismo for a long long time now. And have also put the paper on the bottom and plugged it during an early morning non awake coffee brew.
Hahaha nice! Twins with Gagne
@@LanceHedrick I do have a bit of beard envy. Just finished the video. Great info. I had tried a paper filter in my robot basket a while ago but found cutting AeroPress filters into smaller circles tedious. Going to give it another go now and try and stick with it, redial in etc etc.
As an MMA fan I now know what it would sound like to have George St. Pierre discuss coffee theory. #blessed 🇫🇷 🇨🇦
Hahaha! Truly
@@LanceHedrick “I was not impressed by your extraction” 🤣🤣🤣
ua-cam.com/video/gX3sEGtG8mQ/v-deo.html
Lol *punches in face*
Always enjoy your videos...so much GREAT info. I had never imagined that the basket bends a bit under pressure. I am wondering if the video you did awhile ago concerning using a lower pressure setting also lessens the 'bend'. Currently looking into aftermarket flow control to see if that will accomplish the same thing. thanks again for all work on our behalf...
6 bar will also make normal baskets bend, yes
What if you made the puck convex, a rounded hump in the center and thinner around he circumference, what that allow for better extraction?
I did not hear comments about how using the paper requires the grind to be much, much finer in order for the shot to pull within the regular 25-30 second window. This is a great benefit in terms of extraction.
A faster flow sort of implies a finer grind. In my espresso basics, I discuss the benefits of a finer grinder regarding opening up extraction.
@@LanceHedrick while this is true it might be confusing for someone trying it for the first time as the shot will pull fast enough to think you messed up. I think it’s worth a quick mention
Hi Lance, very nice video, as always. I'm just going through your older videos and discovered this one. Quick question: do you know if there's any testing of a puck screen with a paper filter on top of the puck? One paper filter on the bottom, one on top and a puck screen over all this.
I use filter paper at the bottom of the puck for most of my espresso shots, particularly with lighter roasts. In my experience the weave of the paper matters a great deal. I use 55mm Whatman laboratory papers with 15g VST baskets. The three I use are Number 1 which has a pore size of 11 microns; Number 4, pore size 25 microns; and Number 5; pore size 2.5 microns. Number 4 is the fastest, Number 5 the slowest; and number 1somewhere between them. The difference in flow rate between Numbers 4 and 5 is great, and so is the consequent differences in flavour.
Yup. Correct. I have a few whatman, but don't use the only because they arent food grade (I know they aren't harmful, but the majority seem scared if not FDA approved). Grade 5 is fun, but there is a weird aftertaste with it that I, Rao, and a few others have noticed.
Fascinating. Thanks for this☕
Paper filters of the correct size are more available (June 2023) , would using a paper filter on top of the puck (as well as the bottom)instead of a metal filter work? Would it help to reduce residue going into the solenoid backwash?
I have read people complain that keeping the metal filter clean is an additional chore and they don’t like digging it out of the knock box. SG
Correct. The top filter will help with that. The screen is easy to clean with an ultrasonic jewelry cleaner. Not too expensive
Lance, so my understanding is that with a 58mm basket you want a 55mm paper filter. With a 53mm basket, would you advise a 50mm paper filter?
What about using a paper filter on top as well as the bottom instead of a puck screen ? Does that do the same thing as the puck screen keeping it clean?
Is there any research about pre-rinsing the paper filter vs not in terms of extraction? how about difference in taste?
Very interesting Lance. I had no idea we Canadians were pushing the frontiers of coffee. I live in Waterloo -just a few blocks from the perimeter institute for advanced physics (Steven Hawking used to spend some time there), I wonder if I could get them interested in abandoning their search for quarks, black holes etc. and switch to coffee. Coffee research is certainly more relevant to my life than that other physics stuff 😄On that portafilter though, $495 (that's Canadian, but still), for a portafilter!!!!!!! I sure hope someone else starts producing these better portafilters at a price that isn't, out of this world!!!
Hey Lance, great video as always! I think this type of content will do well in podcast. Look forward to hearing from you on podcast platforms 😉
Haha we will see! Considering it heavily
Even Peter Venkman knew “never cross the streams”
Jonathan when you hear him talk, you can close your eyes and believe it’s George St Pierre talking.
Wow, I love vids like this one! As a Flair Classic user I can't wait to try a filter to see if it helps improve the uniformity of flow in my shots. I'm mostly a V60 guy but I do break out the Flair occasionally and lately it seems like my puck prep has gone to hell. I'm getting splatters and spurts like crazy and I'm doing exactly (near as I can tell) the same puck prep (WDT and tamp). I've not observed anything as dramatic as the photos you showed when examining my pucks but I do see different shades and assumed it was a sign of uneven extraction.
It seems that the name of the game is "uniformity of flow". Of course that makes sense but how to get there has been the 'rub' as it were...
This is fascinating. I'm now looking for a punch to make filters for my Flair pro 2!
Heck yeah! Do it!
I use a 1.5-inch punch for the Pro2
@@dudea3378 Thank you, that helps
Fascinating!
If you are going to use a puck screen, do try having it hot and wet (filled with hot water) when you place it on the puck. I have refined this technique over quite a long time as it has nuances. Of course, if you are emulating a Londinium machine extraction with a Flair 58, then the issue of the shower screen is not there at all (for either machine). There was a guy that built a portafilter out of transparent material and you could see what happened to the puck under different scenarios which helps to understand what the screen, (as well as how the extraction is initiated) affects.
Yes I've seen the transparent PF. Issues with that are the walls have much less friction than a metal basket so can't really say it replicates it 1:1. Many have been doing puck screen heated and wet for a long time. This is just a video discussing what we do know objectively, not anecdotally, which is what has been splayed online for forever. A step in the direction of objectivity
@@LanceHedrick The transparent portafilter shows you what happens at the top of the coffee bed which is useful information but has little to do with the surface viscosity at the side of the basket. I agree that the transparent portafilter is useless for drawing conclusions based upon any extraction it performs for many reasons. The video has no speculation or referenced experiment that I take exception to. It was claiming that being an astrophysicist gave validity that attracted me to watch this video and was pleased at the quality of Jonathan's presentation.
Haha yeah. Apologies for the clickbait. But when your friend is an astrophysicist, I feel like there is an obligation to leverage that haha!
I've tried using a puck screen but it was a mess (fishing it out from the spent puck is no fun). Have you measured the impact on brew temperature of having this chunk of metal in the mix? Are we supposed to pre-heat the puck screen between shots?
Very interesting 👍
I ordered a Pullman 17-19 gram basket and Good Brothers Coffee puck filters to replace my BDB stock one without filter.
Can’t wait to try out.
So if I understand correctly if i change nothing other than basket and add filter paper my flow rate will be faster?
So if it takes 30 seconds currently to achieve 36g out I will have to grind finer to maintain same time?
I've seen it twice. Very informative. Thanks Lance and Johnathan 👏 however I think it would be better to discuss how we should pour water on to the Flair brew chamber in order to maintain consistency. Or maybe it doesn't affect the puck at all, but it would be better to mention it. By pouring water I mean w/o any other stuff but kettle
This video isn't about the flair or thermal stability. Maybe a future video! Thanks for watching
@@LanceHedrick I know, but many people who are using puck screen probably have Flair 😁😃
Sorry but not really. All flair 58 users use a puck screen but that doesn't mean most people using them are flair users. It's a bit like saying cows eat grass so if an animal eats grass it's a cow. Puck screens are used widely in espresso communities. As a flair 58 owner I would say we are in a small minority of the total puck screen users.
Love to see two scientists talking shop.
I love you Lance!
Lance, which video was it that you used the Unifilter? interested to see your findings about it
Is there any recording of the lecture available? Even if it’s paid?
Lance you are not only a good barista, but a good journalist also
I wanted to ask about the puck screens
Do you thing that they drop the temperature of water before hitting the puck?
I used to ask why they put cloth atop the mouth of someone they torture via "water ingestion" (i guess) in movies.
Is it safe to say that placing a paper filter on the bottom of the puck is the same concept?
would wetting the entire paper filter before placing it in the puck be a good idea? You seemed to suggest wetting the screen might help. Does that apply to the paper filter as well?
My pucks seem to layer into 2 or 3 parts and sometimes within the layer, I see very dark areas. I have tried almost everything to fix my channeling issue and starting to think about getting a duomo the eight even though it is so expensive. I have a baratza sette 270 wi and might upgrade to a niche or eureka also.
When will be get a definitive Lance testing video on the Unifilter!?
Can you clarify a bit more at the very end of the video when you discussed the expansion of the puck and the puck screen hitting the shower screen/screw? Other than the physical damage to the puck screen becoming indented by the screw, is this preferable in terms of shot extraction/taste by preventing the expansion of the puck and "having the same effect as a spacer"? Or should we aim to under-dose the puck to provide room for the puck screen to be lifted up and so it does not interfere with "the dynamics of the shot"?
Neither. Just preference. Hitting something and preventing further expansion just increases body of the shot, per Gagne.
My Normcore 58mm 1.7mm screen had a clear indent from my Rancilio Silvia v6 running an IMS 18g basket with 18.3g of medium roast. I just figured it was part of the process. I'm definitely going to have to try the filter paper in the bottom of the portafilter now.
Gonna try the filter paper on the bottom of the basket tomorrow. Shouldn't I expect to get less body though since I'm now basically making paper-filtered espresso? Curious to see if I'll lose all the tiger striping too. Thanks for the knowledge as always, Lance!
James Hoffman says that you might loose some body but its almost not noticeable.
I don't think you really lose any. The theory that oils are held back by that tiny paper filter under that much pressure is unfounded, imo. Have not noticed that with shots over .5 bar.
Will try this tomorrow on my cafelat robot...
Do it!
What effect does using a bottom filter have on a Flair 58 pressure?
These guys always test with top tier equipment, I'd be curious to see them test with lower tier machines that have subpar shower screens or other imperfections
This is a good point! Though, if someone can pony up for a mesh filter, they could pony up for a shower screen first haha!
So this May be a stupid question. But does a paperfilter on the bottom tolerate (deep) wdt
Yep, I use a dry paper and no issues. I have noticed that there IS a difference in taste between a pre-wet and dry paper...
So @lance .. Unfilter review soon? 😀
I would think that if you put the puck screen inside the portafilter basket, and pulled a little water through (like when you preheat the basket/clean it out), then that would also help to “pre-wet” the puck screen as well. ((I do this when I preheat my Picopresso- I put the puck screen in the empty basket so that I preheat/wet everything))
Where do we buy the espresso paper filters? Any good companies/sources
Very interesting! I would love some more content like that, with this kind of guests. Two questions:
Does a filter up of the pack make any difference? Does it work like a puck screen or its useless?
Do you have to wet your filter before putting in on your basket? Is it necessary or harmful for your extraction?
I am not sure I understand "does a filter up of the pack" means. Let me know! And I do wet the paper filter with the steam wand and then wipe the sides of the basket dry
@@LanceHedrick yeah sorry, i meant putting the filter on the top of the puck like you would put your puck screen.
@@ElectTheChopStick I'd like to know this as well! I'm using filter paper both under and on coffee puck - latter mainly because it's easier to remove puck screen after the brew and I guess water could spread more evenly on the puck. Anyway, I get really dry pucks and clean filter basket after each brew and I'm using low end machine (BBE) so it's matter of workflow as well.
Oh! I'd imagine it might, but would be small like the screen.
Bbe is a great machine! Don't under sell that beast!
It would be awesome if you did a video on putting the filter paper on top of the puck verses on the bottom of the portafilter. I would love to know the difference it makes in extraction, If any. Also, would it be redundant to do both?
So is the idea to grind similar with paper and pull faster I.e. turbo, or to grind finer with the paper to stay within 25-30 second range???
I don't care that puck screens don't improve extractions.
The most important thing to me in home espresso when considering a new product after flavor is workflow and maintenance. As mentioned in the vifro, this screen has extended the time in between cleaning my shower screen by so much that I don't even worry about a dirty screen anymore affecting flavor and flow rate.
Exactly what Gagne and I said in the video. We both use them. There has been a lot of speculation as to some sort of majestic quality they hold that hasn't been noticed in Data collection.
I am wandering, can a paper filter on top of the puck replace the mesh screen in the same way ?
Since I added a spacer to my DE1, I can’t use a mesh screen on top anymore…
To hit that 100K mark you need to come to Montreal, and make your show at the Planetarium with Jonathan Gagné. That would be really special.
That would rock
If the sides don't extract as much as the center, doesn't this mean that having a non-WDT or distributed shot, where the center of the puck is more dense than the side, can help counter this difference in extraction?
All this is interesting, but is there any difference in cup?
I believe we hit the purpose in the video, but I'll reiterate here. The biggest thing is consistency. There is an increase and improvement in extraction, which directly correlates with flavors a la balance and depth of flavors, but you'll have less waste with more consistency
My wife has been using hand cut paper filters on the bottom of the filter basket for years and years, but hasn’t communicated this to anyone but me. She now says she deserves to get the Nobel price for that, LOL.
One thing about the bending of the bottom of the filter basket due to the pressure exerted during extraction that seems rather positive to me, is the fact that coalescence of the stream prevents unnecessary temperature drop of the espresso on its way to the coffee cup. Would you agree on that, Lance?
Does the water flow resistance discussion apply to pre wetting the paper filter as well? It seems like pre wetting could help it stick when using a dosing cup?
Yep! I prewet the bottom filter with the steam wand
I've been using a puck screen for over a year with my Flair 58. I do notice a faster flow after a deep clean, so how do the oils that remain inside the puck screen influence things? It's fairly stable shot-to-shot so it feels like the amount of 'stuff' gets exchanged with every shot. Maybe that's why wetting makes a difference ?
Since the exact size is important, is there a way to get regular paper filters to be that size? Not sure how to cut exactly sized circles
Using a 1.5 inch hole puncher to make perfectly sized filters for my 54mm basket rn. Also thought about using a compass and cutting manually but thats too much work.
Does the unifilter still need a bottom paper filter?
Yep!
Hi Lance,
I commented on one of your other videos that was more relevant to this topic. But I am wondering if you have any recommendations for steam pitchers, specifically just for steaming. (I am using the Slow Pour round tip pitcher for latte art.) It would be nice to have a small and large steam pitcher for different size drinks, but it is not necessary. I was not sure which pitcher you would recommend and if you would recommend using a glass steam pitcher.
I would really appreciate your guidance.
Thank you!
If you do decide on making a podcast, it’d be cool if you upload this as one of the episodes!
Oh for sure! Good idea
So one question remains. Wet or dry paper filter? I'm assuming dry but I'm very curious about this.
We both wet with steam wand. This helps set it so there aren't folds water could get to
Very interesting video!
Thank you!
Good brothers coffee sells the the papers for the portafilter
Oh nice! Good call
PP papers for the win!
Ss v60 filter paper too thick for using as a bottom paper filter? Would chemex paper be better?
I think chemex are better but any filter will so the job.
I prefer chemex between the two
Please analyze Nanopresso and Picopresso ... THANKS