as someone who fell deep into the espresso hole over the past 8 years (from an $800 saeco to a $3000 profitec with a few in between), i see several problems with this.
First, CO2 -WILL- enter the brew. There is no way to stop it. This will create carbonic acid and elevate the pH. Which absolutely will impact the flavor. Part of the extraction "dialing in" process is determining the dose, temperature, grind, and duration for a new bean (and as it ages). The last thing you want it so add more acidity to the flavor. Some people do like sour espresso, I do not, and I think I'm in the majority.
Second, consistency of pressure. A CO2 canister output pressure changes with temperature and volume. An espresso machine uses a pump (and some a PID) to regulate this.
Third, this thing will probably explode after a few weeks. You can't subject plastics to this type of pressure. But OP did suggest using metal in the next version.
Fourth, health. Plastic + hot water is bad, add extreme pressure and it is even worse. Kick it up a notch using 3D printed plastic, which is a nowhere near food safe. I'm not too far into the "don't eat out of warm plastic" group, but i'm close. This would concern me.
I think it is a cool build. But a Bialeti is sufficient if you don't want to drop thousands on espresso machinery. Also in the running, the early Nespresso designs, not the rotary one. Both will get you into "americano" territory.
> A CO2 canister output pressure changes with temperature and volume
Temperature yes, volume, not really. The CO2 is in liquid state, maintaining its vapour pressure. Although if the starting volume is low, then the liquid could substantially cool down during the extraction and lower the vapour pressure that way.
All of this is irrelevant though, as the pressure is regulated down to espresso extraction levels during the extraction. It looks like it's done by hand by eyeballing the pressure gauge, pretty wild.
Also not much CO2 enters into a hot liquid, CO2 solubility is drastically down at this temp, as the article notes.
>Fourth, health. Plastic + hot water is bad, add extreme pressure and it is even worse. Kick it up a notch using 3D printed plastic, which is a nowhere near food safe. I'm not too far into the "don't eat out of warm plastic" group, but i'm close. This would concern me.
It doesn’t look like the coffee or water touches the plastic, it goes into a metal Cafelat Robot basket then is tamped with a metal screen on top.
The screen in between the filter and the chamber top is to prevent grounds from entering up into the chamber, but boiling pressurized water absolutely does flood the entire chamber including the plastic region. (It's not just a wall of pressurized water in nice straight lines, it's a mixture of solids liquids and gasses.) Eg: When I clean my E61 group head, I have to remove a fine mesh filter to get to the brass outflow fitting, and it is still covered with oils from the coffee.
bummer. it can be dialed out, it just takes tame, and sadly the vast majority of baristas use a computer controlled grinder and machine and just push-shots all day long. if you find a place with someone in their 30's with weird facial hair or tattoos pulling shots, they're likely to invest more of their personality in understanding espresso, which is better for your. tell them to pull the shot "lungo" (longer) so you get more of the bitter tail. or tell them increase the boiler temp.
I would pump up the tank to ~130PSI, getting my morning exercise in. I would exhaust it through the coffee. If I wanted to get fancy, I might have an extra intermediate stage so I can use fresh air, rather than air which has been through my bike pump.
I'd like to be able to buy something like (any) of these. My requirements:
- Cheap
- Reliable
- Makes good coffee
Nice-to-haves:
- Compact
Anti-requirements (which should make this possible):
- Fast to use and practical in a fast-paced environment.
I make one cup of coffee a day, and it's a ritual. I'm okay with this taking a while, needing to work a bike pump, or whatnot. Slow is okay.
It's an espresso machine that's fully manual. You create pressure by using a lever. Water is manually poured in.
Cheapness is hard to have in a product that's big, heavy and involves big chunks of metal, but on the good side a well made one should last forever -- nothing much that can go wrong, and it's a purely mechanical device that can be taken apart.
+1 for a lever! I found a busted up old La Pavoni years ago, replaced all the seals and it’s been good to me ever since. There’s a bit of art to pulling a shot on a lever but once you get used to it, it’s a really fun way to make your coffee every day.
Love levers! I have three going on four, they're pretty addictive.
These days you can get a very good one (Flair Flex) for $99! That, some good beans and a bit of knowledge and you'll make coffee on par with any shop out there.
I got a pico around a year ago. It is the best product easily made by them the others are watery sort of thicker normal black drip coffee. Pico when the grounds are grinded to the correct diameter(very small) makes espresso shots almost or in comparison to a cafe shot! It's one of my favorite purchases for 129 on amazon. Needs a scale for sure, I also got an extra Normcore 51mm puck screen to use in it as well. I would say this or the base flair is the best at home espresso that isn't a "machine" Also I can travel with the pico. It's really amazing!
I don't know if the reservoir is big enough but some pumps for tubeless tires do come with an integral tank for an initial rush of air to pop the bead in place.
A gotcha that hits me here is that, by using a pressure tank, you will likely run into a cleaning/humidity problem. You need that air to be flawlessly clean and the act of pressurizing and depressurizing the tank would make that difficult.
Additionally, you need to pressurize near-boiling water as well so you'll need a boiler/water mixing tank. Finally, the temperature of the actual brewing environment is important, otherwise the outer edges will be lesser extracted.
You’re ignoring the grinder, which in my opinion is the most important part of home espresso making. Add at least 200USD for a good quality manual burr grinder.
You can find a Baratza Encore used for ~$100. Gives a surprisingly uniform fine grind (not as good for coarser grinds like french press, though).
Out of the box it's not perfect for espresso because the grind level is in steps that aren't short enough to easily dial in. There's a "stepless" mod and that makes it much easier to work with.
You can find the Timemore C2 for 50 to 60 euros and it is a pretty decent manual burr grinder. And for around ~100 euros you can find decent burr grinder from more known brand. If you are going to spend more than 200USD, you might as well buy an electric one.
If you live in a city it's relatively trivial to buy pre-ground from a good roaster. Not the same as grinding in the moment of course but for a week's worth it's generally ok. Especially for the first coffee of the day.
You may also like the Espresso Forge, which manages to go even more reductive than what you propose, forgoing the pumping, or any sort of leverage, in favour of a piston for you to push on with a basket on the end.
There's an important extra ingredient that you didn't specify: FEA. He did a proper finite element analysis, which is the only way that I would be willing to be in the same room as a 3D printed pressure vessel.
Temperature was interesting though. I assume it partially because the hot water was mostly in contact with metal rather than plastic. I don't know what he printed it from but ABS's melting point[1] is only just above water boiling point. We've got a UV cured 3D printer at work (projet) which has some much better temperature properties.
[1] Technically "glass transition temperature" if you want be all materials-science about it
Modeling with FEA is great but I wonder if he also did a fatigue analysis. It might not blow up the first time, but will it blow up three years later after the parts have been pressurized and thermally cycled 1000 times?
Similar topic which might be of interest to HN readers is the [Gaggiuino](https://gaggiuino.github.io/#/), an open source project that adds a microcontroller to fairly affordable and mechanically simple domestic espresso machines, bringing them (almost) up to par with machines that cost 5x as much
The site would definitely need a rework based on the input from someone totally unfamiliar with the project.
I cannot know from the opening page, what coffee machines the mod is for, but I can see that an STM32 or an arduino nano and some other parts would be needed.
Not really informative, no pictures on the opening page to show something like before/after, to showcase the benefits, etc.
Yet there is a rickroll...
This is not really sympathetic, but yeah, I can see the begging icon (support paying for a professional technical writer)... but this is also really backwards in my opinion. First you should sell the project to me, then ask for donation.
While the engineering contents might be great, the presentation is very low quality, to put it politely.
I've built one of these based on the instructions and use it daily (and love it!), but the tone of the site is pretty reflective of the project overall. It's definitely a really impressive hack and I appreciate all the hard work that's gone into it, but could really use a little more user-facing empathy.
I'm not sure if I'd recommend it to someone else - and if I was doing it again I'd probably spend a few hundred more (than the gaggia + parts cost) and just buy an off-the-shelf machine with the same feature set.
I feel the same, as someone who has a Gaggia Classic collecting dust and has long considered splurging on a near-$1000 option because I want all these features...
This is so vaguely written as to seem far more daunting than it probably should, it's unclear how much money or time it would cost me, I don't even know where to start with it. Cool idea, but totally unapproachable to someone without extensive related background.
A bit less DIY but similar functionally is the kit Shades of Coffee sells that also adds PID to the Gaggia classic.
If you're just after the functionality of a cheap espresso machine with PID that takes a lot less effort.
If anybody's interested in a packaged solution, Auber Instruments has been making PIDs and timers for Gaggia and Rancilio machines for a looong time. Their support is also top notch. (I use their PID with my Silvia)
That might be one of the reasons they're trying to fundraise for a technical writer! I think the docs currently serve more as an installation & troubleshooting manual, and assumes some kind of familiarity.
Lance Hedrick in his latest video (review of Decent XL) mentions that he got the Gaggiuino parts, but haven't got around to building it. I look forward to that video, whenever it comes out.
Yeah, I’m looking forward to his experience. I’ve been on the fence about whether to build a Gaggiuino myself, or sell the GCP and upgrade to a dual boiler machine. I don’t really care for flow profiling, but more stable temps and auto shot timing would be nice to have. And I make a lot of milk drinks so a DB would eliminate some of the wait time and need to flush the boiler.
I've been buying cups of coffee on and off from coffee shops for years. Each cup was 2-4USD. Sometimes i also did pourovers but that shit took forever.
Finally got a used Delongi bean to cup for less than $200 and my god what I've been missing. I also discovered that, for me, reducing the amount of water that passes through the coffee puck for each shot makes the coffee so creamy and less acidic.
This is call a 'ristretto shot'. In some of the starbucks reserve locations you can get a large volume of ground coffee and a ristretto shot, and it is very creamy without as much acid/tannins.
Also, the ristretto shot is often used in flat whites - one of the main differences (the other lesser one being milk texture)
Starbucks is rather bad coffee though, without all the syrups you will notice it more. Honestly I have a bean to cup (Krups, previously also had DeLonghi) and prefer to take a small thermos along for decent lukewarm coffee all day rather than to pay outrageous amounts for mediocre coffee and a throwaway cup. Living in Italy or Portugal I'd probably not need that as there is excellent espresso at every corner, but most other countries it's hit and miss and the Anglosphere generally just bad coffee.
> Sometimes i also did pourovers but that shit took forever.
Really? I use the hario switch for my medium roasts and I brew 2 min tops, usually a hybrid immersion/pourover, but I can do just straight pourover in that time.
Firstly I would say that the grinder makes an outsize difference relative to cost so I would strongly recommend you first invest in something like a Mahlkohning Vario (this is what I have as a present from my lovely wife who just by pure coincidence also likes nice coffee).
Then I have a friend who is an ex-high-end-barista and gigantic coffee snob (like coffee snob's coffee snob) and insists that once you have a good grinder it's more important to get a reverse osmosis filter than a high-end espresso machine. Make of that what you will, but if you want to investigate that he swears by this book[1] and having drunk coffee at Colonna and Smalls in Bath (owned by one of the guys who wrote the book) I can say he might be on to something. Certainly every cafe that does amazing coffee has an RO filter.
I have an ECM entry-level machine and it's great. I dont' need (or ever use) the frothing parts unless we have guests but they do the thing they are supposed to and the main coffee bit works great. I wish it could get a bit more pressure but it makes a good cup of espresso if I tamp well and use nice beans (which, you should always use nice beans. There's really no excuse for that one).
In the UK you can get great home coffee equipment as well as advice from Bella Barista[2]. Probably most countries have a place like that but even if you're not in the UK I would look at what they have as being a good starting point.
I’ll check out the book but while I wait for shipping, could you share what you do with the RO water? Do you put your own mineral and salt profile into it, or just use it as pure H2O? I have an RO filter and build my own water profile for my homebrew beer, hadn’t started down that road for coffee yet.
RO is really important (along with remineralization), but you can buy RO water without a filter, so if you're not making several coffees a day, maybe it isn't worth it. If your supermarket has available RO water to fill jugs even better.
I would agree with your friend. I typically do pour over, and getting a nice grinder was a huge upgrade for the coffee flavor. I also only use filtered water. Next is fresher beans.
Frowned upon I'm sure, but for espresso a machine like Nespresso or L'Or has worked fine in a pinch.
I have a Mazzer Mini grinder that's pretty old and I suspect it is the weak link in the chain (paired with Rocket espresso machine). Is there an easy way to tell if the grinder is doing its job well, e.g., some reliable way to examine the grain size?
In that segment, Flair is the right answer. It’s simple, durable and capable of delivering 100% real espresso, on par with high end machines. It’s also not weird, you can actually use it every day and prep the drink in just a few minutes.
Also note that Flair 58 is compatible with regular-sized generic espresso accessories.
The Robot made great espresso, and I was just about to buy one for myself but then the Meticulous Espresso machine (https://meticuloushome.com/) was announced on kickstarter and I splurged on that instead (deliver by end of year, or so they say.)
If for some reason that doesn't work out, I'll get the robot
Think about budget and if your budget is high enough, if you make several milk drinks back to back and need more than a single boiler machine. At different price points, I'd look at Gaggia classic pro, profitec go, profitec pro 300. You'll also have to budget for a proper espresso grinder. Check out https://www.espressocoffeeshop.com/ for the best prices on grinders.
The Kamira appears to be a moka pot, not an espresso machine.
Jura E8 here. Single button cappuccino box, competently engineered. Milk goes through a small subset of the machine which disassembles easily and there's a cleaning tablet option for not taking it apart. I think it could be wifi attached and persuaded to make one as an alarm clock but that's more bother than I've gone to.
That one optimises for minimum hassle per cup of coffee at the expense of up front and running costs. No regrets.
At home I use a Bialetti Venus (moka pot), which makes a pseudo-espresso (longer, with poor crema). Nonetheless I prize this and look forward to it each day. It's about $40.
I find it somewhat cute that according to this article, $500 is "grows on trees" kind of money. In the espresso hobby, $500 is barely enough to get a decent grinder.
For anyone who is discouraged by this (accurate) comment, don't discount the utility of a manual grinder. You can get a 1Zpresso which is a beautiful, durable piece of equipment for a fraction of the cost of an automatic grinder and it takes all of 30 seconds to grind your own beans to perfection.
1Z just issued a recall for the chipping burrs affair on their X-Ultra line. They went for cheaper alloys and people ended up with metal shavings in their cup. Old grinders seem to be fine. I’d wait a hot second before getting a 1Z right now
Although I would like to discourage anyone from getting a Eureka (Silenzio). grind retention is insane on those, and the higher priced models are the same flawed grinder with more LCD screens.
I love my DF64. I found it on sale, and informed my wife that it'd be her Christmas and birthday present to me: totally worth it. Even with a $100 DeLonghi EC155, the difference from the grinder is incredible.
Hmmm. I was a teen in the late 1980’s and I recall vividly a Steam Punk espresso machine I saw at a SOMA art gallery in San Francisco.
It had a volleyball size spherical steam chamber heated by a propane wok burner. I’m fuzzy about the connection to a smallish brew chamber with a foot long lever arm. It was all a play on scale. The whole setup was somehow a unified whole out of a Miyazaki anime.
DIY meets art. Would be thrilled to see that device again compared to my memory palace.
Readit News
First, CO2 -WILL- enter the brew. There is no way to stop it. This will create carbonic acid and elevate the pH. Which absolutely will impact the flavor. Part of the extraction "dialing in" process is determining the dose, temperature, grind, and duration for a new bean (and as it ages). The last thing you want it so add more acidity to the flavor. Some people do like sour espresso, I do not, and I think I'm in the majority.
Second, consistency of pressure. A CO2 canister output pressure changes with temperature and volume. An espresso machine uses a pump (and some a PID) to regulate this.
Third, this thing will probably explode after a few weeks. You can't subject plastics to this type of pressure. But OP did suggest using metal in the next version.
Fourth, health. Plastic + hot water is bad, add extreme pressure and it is even worse. Kick it up a notch using 3D printed plastic, which is a nowhere near food safe. I'm not too far into the "don't eat out of warm plastic" group, but i'm close. This would concern me.
I think it is a cool build. But a Bialeti is sufficient if you don't want to drop thousands on espresso machinery. Also in the running, the early Nespresso designs, not the rotary one. Both will get you into "americano" territory.
Temperature yes, volume, not really. The CO2 is in liquid state, maintaining its vapour pressure. Although if the starting volume is low, then the liquid could substantially cool down during the extraction and lower the vapour pressure that way.
All of this is irrelevant though, as the pressure is regulated down to espresso extraction levels during the extraction. It looks like it's done by hand by eyeballing the pressure gauge, pretty wild.
Also not much CO2 enters into a hot liquid, CO2 solubility is drastically down at this temp, as the article notes.
It doesn’t look like the coffee or water touches the plastic, it goes into a metal Cafelat Robot basket then is tamped with a metal screen on top.
It's very hard to find a non-sour coffee where I live, and not much easier to find a non-sour espresso.
Or 9barista/cafelat robot
If I were doing it, my design would consist of:
(1) A bike pump (goes up to >200 PSI)
(2) A pressure tank
(3) Two valves
I would pump up the tank to ~130PSI, getting my morning exercise in. I would exhaust it through the coffee. If I wanted to get fancy, I might have an extra intermediate stage so I can use fresh air, rather than air which has been through my bike pump.
I'd like to be able to buy something like (any) of these. My requirements:
- Cheap
- Reliable
- Makes good coffee
Nice-to-haves:
- Compact
Anti-requirements (which should make this possible):
- Fast to use and practical in a fast-paced environment.
I make one cup of coffee a day, and it's a ritual. I'm okay with this taking a while, needing to work a bike pump, or whatnot. Slow is okay.
It's an espresso machine that's fully manual. You create pressure by using a lever. Water is manually poured in.
Cheapness is hard to have in a product that's big, heavy and involves big chunks of metal, but on the good side a well made one should last forever -- nothing much that can go wrong, and it's a purely mechanical device that can be taken apart.
These days you can get a very good one (Flair Flex) for $99! That, some good beans and a bit of knowledge and you'll make coffee on par with any shop out there.
https://www.wacaco.com/collections/picopresso
https://www.handpresso.com/en/handpresso-pump-black-351.html
Still hand pumped, looks a bit less like a bike pump though!
On the other hand, a Flair Neo works fine
You’re ignoring the grinder, which in my opinion is the most important part of home espresso making. Add at least 200USD for a good quality manual burr grinder.
Out of the box it's not perfect for espresso because the grind level is in steps that aren't short enough to easily dial in. There's a "stepless" mod and that makes it much easier to work with.
You may also like the Espresso Forge, which manages to go even more reductive than what you propose, forgoing the pumping, or any sort of leverage, in favour of a piston for you to push on with a basket on the end.
Temperature was interesting though. I assume it partially because the hot water was mostly in contact with metal rather than plastic. I don't know what he printed it from but ABS's melting point[1] is only just above water boiling point. We've got a UV cured 3D printer at work (projet) which has some much better temperature properties.
[1] Technically "glass transition temperature" if you want be all materials-science about it
I cannot know from the opening page, what coffee machines the mod is for, but I can see that an STM32 or an arduino nano and some other parts would be needed.
Not really informative, no pictures on the opening page to show something like before/after, to showcase the benefits, etc.
Yet there is a rickroll...
This is not really sympathetic, but yeah, I can see the begging icon (support paying for a professional technical writer)... but this is also really backwards in my opinion. First you should sell the project to me, then ask for donation.
While the engineering contents might be great, the presentation is very low quality, to put it politely.
I'm not sure if I'd recommend it to someone else - and if I was doing it again I'd probably spend a few hundred more (than the gaggia + parts cost) and just buy an off-the-shelf machine with the same feature set.
This is so vaguely written as to seem far more daunting than it probably should, it's unclear how much money or time it would cost me, I don't even know where to start with it. Cool idea, but totally unapproachable to someone without extensive related background.
https://www.auberins.com/index.php?main_page=index&cPath=6&s...
Finally got a used Delongi bean to cup for less than $200 and my god what I've been missing. I also discovered that, for me, reducing the amount of water that passes through the coffee puck for each shot makes the coffee so creamy and less acidic.
Also, the ristretto shot is often used in flat whites - one of the main differences (the other lesser one being milk texture)
Really? I use the hario switch for my medium roasts and I brew 2 min tops, usually a hybrid immersion/pourover, but I can do just straight pourover in that time.
Then I have a friend who is an ex-high-end-barista and gigantic coffee snob (like coffee snob's coffee snob) and insists that once you have a good grinder it's more important to get a reverse osmosis filter than a high-end espresso machine. Make of that what you will, but if you want to investigate that he swears by this book[1] and having drunk coffee at Colonna and Smalls in Bath (owned by one of the guys who wrote the book) I can say he might be on to something. Certainly every cafe that does amazing coffee has an RO filter.
I have an ECM entry-level machine and it's great. I dont' need (or ever use) the frothing parts unless we have guests but they do the thing they are supposed to and the main coffee bit works great. I wish it could get a bit more pressure but it makes a good cup of espresso if I tamp well and use nice beans (which, you should always use nice beans. There's really no excuse for that one).
In the UK you can get great home coffee equipment as well as advice from Bella Barista[2]. Probably most countries have a place like that but even if you're not in the UK I would look at what they have as being a good starting point.
[1] https://www.waterstones.com/book/water-for-coffee/maxwell-co...
[2] https://bellabarista.co.uk/
Frowned upon I'm sure, but for espresso a machine like Nespresso or L'Or has worked fine in a pinch.
Also note that Flair 58 is compatible with regular-sized generic espresso accessories.
The Robot made great espresso, and I was just about to buy one for myself but then the Meticulous Espresso machine (https://meticuloushome.com/) was announced on kickstarter and I splurged on that instead (deliver by end of year, or so they say.)
If for some reason that doesn't work out, I'll get the robot
The Kamira appears to be a moka pot, not an espresso machine.
That one optimises for minimum hassle per cup of coffee at the expense of up front and running costs. No regrets.
I’ve had a ROK manual for 10 years and have given several as gifts. Upgraded/replaced most of the parts outside the frame.
I had a part break earlier this year and they sent me new ones for free.
But yeah, definitely don't discount manual grinders. But note grinding for espresso with a handgrinder is... an exercise. lol.
Although I would like to discourage anyone from getting a Eureka (Silenzio). grind retention is insane on those, and the higher priced models are the same flawed grinder with more LCD screens.
It had a volleyball size spherical steam chamber heated by a propane wok burner. I’m fuzzy about the connection to a smallish brew chamber with a foot long lever arm. It was all a play on scale. The whole setup was somehow a unified whole out of a Miyazaki anime.
DIY meets art. Would be thrilled to see that device again compared to my memory palace.