Great video ! This was a much needed discussion. The gripe I had with that study is that I wish they also varied dose (i.e. bed depth) because if you don't, and swap to a different geometry, you get a very different bed depth which affects not just brew time and bypass but also that bottom-layer which extracts differently with concentrated water. I would not be surprised if the impact of bed depth on taste was as significant or more significant than dripper geometry, and currently the effect they categorize as dripper geometry includes both geometry and bed depth.

Thank god finally something I might be able to afford to have an opinion on

Lance just picking a topic we ask for randomly and bashing it with testing until he has answers is my favorite kind of video

This is the kind of content pretty much no other creator is making right now. It's fantastic and super interesting. Thank you. Even if it is not one of your most performing videos (I think I saw you post that on Instagram), the content is really good.

Gotta love that roast level was found to be the largest variable in taste, but more and more roasters are neglecting to include it in the description of their coffees.

Flat bottom brewers they make the coffee world go round

Goodness that was a packed video! I appreciate you and your content Lance. I read Gagne’s blog a lot before his book came out, I haven’t read the book, but from his research process and blogs I took away that flat bottom brewers by design allow less bypass and more consistent extractions. He did a lot of research with the stagg and that’s now my daily driver. I think brew technique is hugely important and possibly more important than brewer type, 3 vs 6 pulses is going to have a big impact on bypass because the amount of water above the level of saturation of the bed will vary: if the bed “saturates” at 30g and your pour is 50g then there is minimal available to bypass, but if your pouring 100g+ or always maintaining standing water above the bed then you’re begging for bypass; a lot of drip brewers do this, a steady stream of water that never drops below the level of the bed. Some brew recipes have you stop pouring as soon as you reach a saturated bed, which results in 10+ pours and would surely result in less bypass. Two things I assumed you would hit on (but honestly you covered plenty so maybe there should be a part 2?), were the use of agitation to ensure you don’t have hydrophobic clumps of grounds in your bed before pouring or after your bloom (similar to espresso), and the use of immersion brewing or pseudo-immersion brewing like French press/aero press/next level brewer (which Gagne helped design for this very end). Great video, love the content, keep it up!

I swap same beans between CAFEC Flower and Orea v3 and definitely have developed preferences on different days. Some days I want that coffee via cone, some days I want it via flat. I've been doing this for the last few months and all the observations you made are pretty consistent with what I was intuiting, but your level of detail and ways to think about all those details was massively helpful in continuing to dial in how I use these brewers. Thank you!

I love your callout about recognizing how coarser grounds allow for easier management of channeling; how all beds will have channeling and that finer grind sizes are on a tighter balance beam between relatively even channeling and very unbalanced channeling. There's so much push in the speciality coffee brewing world to go as fine as you can until it's astringent and then go back just a bit more coarse. The study you discussed in another video related to, I think turbo shots, and how the curve showed similar extraction on two sides of a hump of finer and coarser where coarser could allow for same output but with more repeatability... that feels like it rings true here, too. Coarser isn't bad, it can be quite good, with some nuance in that discussion.

Fascinating. My take away: controlling my water level is more important than I realized - I want to have consistency of by-pass so ensuring that the water level stays just at the top of the bed, will maximize my extraction / minimize by-pass. I think really that's probably why various recipes call for different pulse patterns of pours. I'll now swirl aggressively on the first small pour to thoroughly wet the bed then use shorter pours only allowing the water level to reach the top of the bed and then letting it drain sufficiently before doing another pour

I love the Physics of Filter Coffee! Been reading it over the last few weeks. Highly highly recommend for anyone wanting to go even deeper into the coffee rabbit hole.

What a great video. I LOVE the more scientific side of coffee which is, unfortunately, less talked about!

“Or we just suck at tasting” Had me laughing so hard! 😂 Love the in-depth analytics, thx for another great video 👍🏽

I was exposed to new vocabulary from your videos. So intellectual, fun and educational! Thanks

This was super informational. I waited for this kind of video for long. From a point of view of a BrCC competitor it is very helpful to know that basket geometry makes a bigger difference then the grind size does. As far as I'm concerned most of the baristas including myself would dial in a coffee using grind size as a primary Variable. Also most of us would use a different grind size for flats and cones. Maybe next time when I'll be dialing in I'll use my preferred ratio for the roast I'll be working with and stick to the grind size that allows for a reasonable brewing time and only change in between a V60 and orea to see which one expresses the coffee in the tastiest way. One more thing that I think would be worth checking is where does the choice of a type of filter place on that scale of impact on the taste. I mean different types of paper filters with different pourosities and thicknesses, but also a check against a cloth filter could enrich the data on this matter.

I got the fellow Stagg x on your recommendation and also got a Fellow Smoosher from Etsy. It leaves a small gap when smooshing kalita filters and I get zero clogged or stalled brews. In fact no matter how fine I have ground with the zp6 it usually drains in 30 seconds following your 2min bloom, slow pour recipe.

Another great video Lance. Please don’t stop making videos, we love them!

Great video with fascinating results! I would also say if someone is bothered by the bypass, they can easily just adjust the ratio without probably noticing negative taste effects. It's important to note that also high strength brews without bypass may not always be the best. The preference for bypass is subjective, as it can contribute to a more enjoyable brew or not. In fact, some professionals bring out beautiful flavor notes, such as florals, by reducing the amount of water they would pour through by around let say for example 30% and instead add that portion afterward as bypass. Additionally, you can observe where bypass occurs more through experimentation. It typically happens at points where the filter makes contact (like the veins on a V60) but also where there is airflow. You can see this yourself at home. To illustrate this, imagine camping in a tent with dew on the outside. The water doesn't enter the tent until you touch the side. Similarly, if you brewed with just a filter and no basket, you would still have some bypass, but less than with a brewer that has many contact points and airflow. It's like having 30 people in a small tent, all touching the sides with their hands. Ultimately if you taste buds like it... That's all that really matters 😊. Greater water and coffee will make all the difference. Cheers

Outstanding video! Everyone can start including in their current/existing brewing discussions these mechanics about bed depth and how number of pours is about depth of water above bed creating bypass for most brewers.

I'm not that long on brewing and I'm far from a good taster, but here's my experience: I notice a clear difference in flavor from coffee that I have at home (very light roast) vs my father (medium) - using the same water temperature, basket and filter paper. Recently at home I changed the ratio - 1/17 based on your tips - and again I notice a difference. So I would say that "statistically significant" is correct in my experience. And... you're the GOAT! Cheers

Super interesting that you say channeling is unavoidable. I m so glad someone finally said it, and it’s Lance “burr man” Hedrick to boot. I ve been realizing more and more that the perfect shot doesn’t exist, but it s nice and fun to strive for it, in spite of it being totally subjective. Would love to see a full video of an elaboration on channelling as i feel there’s a big misconception about the difference between reducing channeling and getting rid of it all together. Thanks Lance!!

Six essential elements said 1:17 yielding 1.25% tds is more palatable to most people. True then, true now. Low and slow v60 has always been my preferred method because of the natural agitation increasing extraction. I consistently get a 1.35% tds with a 1:17 ratio, above what the Coffee Control Chart predicts. As long as the coffee is in contact with water, saturated, I don’t care much about bypass. TDS suggests we’re getting plenty of dissolution and diffusion. Allowing water to flow naturally into the coffee particles does something beautiful for me. I think this is often overlooked for the lack of “evenness” in the geometry. I also think the cooking a steak analogy is erroneous because the heat source of a grill comes from beneath whereas water surrounds a coffee particle. Best video I’ve seen so far about the subject. Thanks for creating, researching, and sharing.

Thanks for the tip about using a tea mesh with a flat bottom dripper! I was experiencing issues with inconsistent draw down times using my Orea dripper, and putting the mesh below the filter seems to have eliminated the issue entirely.

I love how you find these studies and share them. Books are easy to find, interesting studies it's a maze. Thank you for your detailed approach to topics. 🙏

I love it. Have been doing pour overs for years! Playing with temp and grind size. When in a hurry I use stagg x and circular pour. That is going to change and I’m going to stick closer to middle! And going to fill slower and keep bed saturated. No more pausing.

Another top video Lance. Changing ratio instead of grind size is something I’ve been doing more and more lately so it’s nice to get some confirmation of that here.

Just wanted to say that this was a great video and very thorough, I appreciate the time and effort put into this.

Very interesting, never thought of geometry as a major factor before. I usually go for light roasts but that being said, I have noticed that when I try darker roasts, I enjoy darker roasts more when I use a Clever Dripper (which is kind of a cross between cone and flat) than when I use my conical dripper. This is pretty consistent even though I use basically the same recipe in both brewers. I'm sure brewing method has a lot to do with it since the Clever is hybrid emersion/perc brewer, while the cone is pure percolation but maybe the different geometry also plays a part.

Asking to like a video before I've watched the video is a pet peeve mine. But I love Hendrick's singing so much I truly feel I instantly like the video.

This was not only Awesome but also an eye opener as well.

I share your dislike of frilly filters. After trying a lot of drippers, I settled for two - Hario Switch (sometimes I use it just open like a regular V60) and April dripper. I actually use Cafec V60 papers in both, you can fold one so it fits a flat bottom dripper and I'm still able to do it and rinse the paper well before my water boils, so the extra operation doesn't result in any time lost. Great job as usual.

ONCE I WENT FLAT, I DONT WANNA GO BACK TO CONE.

This is why I started watching these videos!

Commenting for the algorithms but also to thank you for saving me some cash. I'll stick to my stove top goose-neck and disregard the Stagg EKG. This hobby really needs a realty check in regards to how much gear we accumulate. Maybe that can be a quick and easy video for you to make - Essential and non-essential gear a home barista should have.

I use water from the coffee shop. Its ro then remineralized with 80 calcium, and the owner may or may not add 20 magnesium. Once I got my water jugs from the cafe, I could taste the quality beans again. Now, I focus on similar factors noted in your video. I wasted a lot of good beans trying spring waters, packets to add to distilled, etc. Even better, there is no charge for a jug of water, but I add a tip for the favor.

You are absolutely Stevie T’s brother, My KZfaq number one favourite. I use flat bottom as these filter papers are readily available in the UK.

Best video explaning the topic, everyone who brews coffee should watch this

Very nice video and very informative....but Dracy's law is the equation of a liquids flow through a porous media. It doesn't take any account of the 'restriction' presented by a filter, so as we use 'filters' to brew coffee this has to play its part in the end result i.e a good brew. I do a lot of experimenting as I have V-cone filters unbleached, Flat bottom cone filters bleached & unbleached, No.2 basket filter unbleached 'all' of these are 0.006" thick. I also buy and use the 8-10 cup basket filters form the $ store bleached, these are thin only 0.002" thick, I fold these up into a No.2 cone, mainly for camping as they are very cheap and light. So my question is 'obvious' the filters thickness along with its 'porosity' will have a great effect on the end result. And those using non-paper filters such as all the stainless steel or plastic mesh filters out there, I have tried these, and they do not make a 'smooth' cup of coffee.

The Ergun equation is the more appropriate equation when it comes to flow through a packed bed (like a bed of coffee) compared to Darcys law. Theres also an extraction (mass transfer) equation at play here. In something like a french press or aeropress where the coffee is mixed in a fixed volume of water, the system will be more uniform in extraction across the bed - similar to a CSTR in reaction kinetics modeling. In a pour-over the solvent flows in a more plug flow manner. Cones yield higher bed heights for the same mass typically so it approaches more closely to true plug flow and would be modeled similar to a plug flow reactor in reaction kinetics.

Lance thanks for the video. I have moved back and forth though cone vs flat through the years. Currently I am team flat (Orea V3) but I enjoy brewing on the Chemex for larger batches. Keep up the great work!

I use both and I can say that flat bottom is more forgiving, produces more rounded cups, while V60 consistently produces more vibrant cups. It's like RGB vs sRGB. Since V60 is more vibrant, any error or mistake will be more pronounced.

This was a great explanation of by-pass. Thanks.

I love my little glass Kalita 155. It never stalls and makes a very good, consistent cup. The convex bottom holds the filter up over the holes. Also, it requires no faffing around with stirring, swirling, or other forms of manual agitation. Very rarely do I find the need to use anything else.

Gonna just FLAT out say it... That intro slaps! Great video man!

Hey Lance, where would you say water chemistry falls in this list? It’s one factor I’m always trying to convince people about… I put it right up there with roast and ratio! Fantastic video as always! Makes me want to pull out my cone drippers - it’s been a while!

This video should be titled "Coffee Brewing Theory 101". Holy cow did I learn a lot.

Thanks Lance for summarizing this paper for us!

Although its dense for naive brewers, but you made Complex into Easy... much appreciated

Great video! I’ll definitely take this info and put it into my brewing. Looks like that tattoo sleeve is coming along, maybe a tattoo tour video in the future? The algorithm probably wouldn’t like that ;)

I started my coffee journey with a Melita and still enjoy it periodically

Excellent video Lance!!

Where is the B75? With the enormous drop area, I would’ve liked it to be compared to other flat drippers!!

I eagerly await part 3: flat bottomed vs conical paper cups!

Best Lance video ever!

This video reminded me how I fell in love with this channel❤

The problem with changing recipe before grind size is that most people, me included, have no idea how to change a recipe to change the properties of the coffee produced, while with grind size it is much more straightforward…. I know the vid is old but yea.

Thanks for the super informative video! Would love to see a workflow guide from you on flat bottom brewers! Thanks!

Really interesting, great video! Thanks very much.

great video, thanks for the insights, Lance!

Great video, Lance! Thanks man!

One style of brewing to rule them all 😂 made my day

Love the yellow - well done Hugo!

Useful and interesting video. 👍🏻 Cheers Lance. 🙏🏻

Vibing with the intro and editing Lance!

Would love to see the Soto Helix reviewed. It should give a good idea if the bypass theory holds water.

I just ordered the Orea V3 an hour before watching this lol. As a current V60 user, it will be interesting to see if it makes for a different type of cup.

The Orea is easily my favorite brewer. I prefer the flat filters that Orea provides, but buying them kinda hurts my head and wallet. I've been using the Kalita 185's and using the negotiator to get around this.

I wonder how an Origami with Kalita filters would compare to flat bottom brewers.

Lance's new catch phrase: "Thats valid".

like this a lot! almost as much as the stone ground satire!

Im excited for the vid (pre watching)! Ill give my feedback after but I always love the vids! And i brew v60 usually

Nice one. Like that you missed the second triangulation. Will definitely give this a go at home between a v60 and an orea. I can refold my v60 paper to fit the orea. So far from notes, not a test, indeed I find a cone to give more highs (or lows😅) and a flat is more even. For carbonic maceration is actually prefer a flat right now because it balances that extra flavour and makes me like it. On a v60 and CM I get way too much.

Informative and charming, as always. This made me wonder, though, why there is all this talk about the evenness of extraction, but no one seems to be systematically testing methods of controlled stirring, like, e.g., 1 full rotation per second (maybe with a plastic spoon to minimize heat loss). After grind size consistency, stirring could be the best extraction equalizer, right?

I’m here for the Ron Jeremy of coffee🤣🤣

The world needs a lance hedrick origami recipe! Preferably Air S.

Not that it matters much for this video, but it should be noted that the aforementioned study was done with melitta style cones and not v60 style cones. Which I'd honestly love to see a video on. I love my beehouse. It was my first dripper, and I enjoy it just as much now as I did years ago.

Loved this.

This is another great video. I would like to see you dial in a coffee keeping everything the same except for the brewer. So, same coffee but with April and Flower for example

I drink medium roast, but I had the best dark sweet chocolate beans as gift.. it turned out to be 100% Thai robusta One of the best beans I ever tried 🤯

Amazing video!!

I really enjoy these videos. Thanks for taking such a curious and scientific approach to making coffee. I am curious though: how do you feel about cloth filters? I feel like they are very polarizing and I personally love them.

Anyone picking else Jonathan Gangne man crush vibes? Great work Lance!

How does this compare to a french press, which I guess if done properly will be a full extraction of all the grounds?

great great great video as usual my friend

Sorry im distracted so much by those unsolved cube back there lol. Wonderful insight. You made me want to convert to pour over.

So excited to watch the rest of this! As a noisy person myself I love your singing and general noise making, I was just wondering if it might be possible to turn the gain down in the edit for those sections where you go all the way to 11? I'd never want you to stop you from getting your Madcon on, it just blew my head as I had the volume set to your speaking volume 🤯 Hope that's an okay request!

Hi Lance, how would you label Aeropress when compared to those flat/conical? Have you ever measured extraction and taste against classic pour over? We are waiting you to visit Brazil and taste our special coffees. ✨☕ Regards!

Temperature for espresso brewing I think should have more of an impact, correct? I think it's safe to assume that more bypass will happen if you fill higher above the coffee bed, there's more area where water can escape without touching the coffee as much, but also I think part of it might be that there's more pressure / weight ontop of the coffee so that might push the water through on the bottom quicker too? Surprised grind size actually made less of a difference than the basket shape, that's interesting. I think I'm more used to the espresso world where grind size (dialing in) will make a pretty huge impact usually. Brew Recipe/Ratio and Roast level is no surprise that's going to contribute even more so.

I think you should contact them to revisit the study with your help and knowledge about the nuances of coffees. Great info. thnx! Love my fellows, I've had it since its launch. I think I need to get a V60 and branch out a bit.

Does anyone still have access to the data from the UC Davis, basket geometry study? I seem to recall EY's were not typical, nor comparable across basket types? (Maybe I remember incorrectly, it was some time ago now). What about practical attributes? Basket filter papers take up more space to store, are frequently unavailable where I live, less practical to travel with, more fiddly generally - hence the ones I use least commonly. If I couldn't get Hario papers with my grocery shop, I'd be 95% Melitta/Clever brews.

Thank you for this awesome vid! I have “the physics of filter coffee” at home and I read through it regularly. A great book, but the way you are able to communicate the major findings really help in understanding it better. And as always, you drop some really cool findings as side notes throughout the video that would be worth making a video on their own. Such valuable information. For example, I have tried to blind taste “papery” taste in filter brews side by side, but that was nearly impossible. One Question: Since brew temp is not statistically significant, would that mean using hot/boiling water to rinse the filter and preheat the brewer is pointless? If using cold tap water to rinse yields the same results, then my workflow would be quite a bit easier and at the same time consumes less energy.

Hmm, then the Hario Switch in immersion gonna let a lot of water bypass the bed. And you want to immerse longer if you really want to make sure the bypassed liquids are well extracted (coffee).

My guess for the reason the water doesn't bypass as much at the bed level is because of the capillary action of the coffee grounds (and the water can't apply as much static force on the filter wall at that level).

Very good video. As roast level is outside the scope of flat v conical, I'd say water quality is a biggie too.

Maybe I should look at my Kalita Wave again... it's been sitting on my shelf gathering dust for years because I've been using my conical brewer and I JUST got a Hario Switch. I think I found it tough to find a recipe that I liked way back then, but there are way more resources now ever since coffee became more of a hobby over the pandemic. I know brewers like the Orea are all hip right now, but I can't justify getting ANOTHER brewer if the Wave works just as well (with a little bit of tweaking). Maybe I need to widen the holes with a drill to increase flowrate and minimize stalling?

Good stuff Lance. If nothing else, it made me want to bust out my Kalita Wave again as ive driftes FAR toward v60 recently.

Hey Lance, great video but what we really need is a comparison of brews made using flat dropper and flat burr grinder vs flat dripper and conical burr grinder vs conical dripper and conical grinder vs conical dripper and flat burr grinder! 😂

everything nice explained 👍also it confirms why aeropress is "better". No bypass, extremely even extraction, really small drop in water temperature...

I wonder if a flat bottomed brewer is just providing the profile of a pourover closer to immersion brewing

I lost focus once I noticed the scumbag 🐷 blower in the background, I simply couldn’t focus on all the other so thank you for that @Emilee Bryant. But Yeah I use both and have done the same brew with both cone and flat. I don’t really think I change much grind settings, I mainly just change recipes to alter taste of a given coffee, also Agree with Gagne point regarding bed dept.