How-To: Make a cheap portable espresso machine

Thought we'd mix things up this week with a low tech How-To courtesy of Hack A Day editor Jason Striegel:

I spent the weekend trying to design a small espresso machine that you can make from readily available parts. What has a homemade espresso machine got that an $800 Williams Sonoma special doesn't?  $770 dollars in your bank account, high-design PVC tubing, and a caulk gun.  You probably have a caulk gun anyway, so let's just make that $785 in your pocket and a fine piece of caffeinated gagetry that you can impress your friends with.

A caulk gun?  Hey, if it�s good enough for Taco Bell guacamole and sour cream, it�s good enough for a fine and delicate espresso, right?

If you just want a nice strong cup of coffee, you can use the homemade espresso machine sans caulk gun too.  Just force the plunger manually and don�t tamp the grounds as hard.  It�s perfect for backpacking!  There�s nothing like brewing a shot or two of espresso atop your favorite 14er� so I�m told.

Ingredients

• Lengths of 1 1/4-inch and 2-inch PVC tubing

• Various pipe joints shown in the above picture (hereafter reffered to as a, b, and c from left to right).  You�ll need two of the bottom right, and a part that mates two 2 inch pipes together (d, not shown).

• PVC cement, and teflon tape

• Some sort of stopper that will make a sealed fit in a 1 1/4-inch tube

• 2 inch diameter portafilter cup

• Caulk gun

• Hot water and finely ground coffee

Construction

Feel free to skip this section if you want to see the device in action and don�t care about the details of its assembly.  The assembled product is shown above and is comprised of three parts: the plunger, the portafilter attachment (where the coffee goes), and the seal/compression chamber.  Joint b on the portafilter attachment and joint a on the compression chamber screw together to form as seal and can be seperated for cleaning.  The portafilter is sandwiched between joints d and b (which are cemented together with a small length of 2-inch pipe.

The seal is provided by two c joints affixed end to end.  Part c has a small ridge inside of it which exactly accommodates the 1 1/4 inch plunger.  I use two of these end to end so that the dead space between them provides a small buffer for any water that slips past the first seal.  We don�t want anyone getting squirted with pressurised hot water.  The very top of the seal unit is removed and affixed to the bottom of the portafilter unit.  This keeps the length down and prevents the filter basket from striking the end of the caulk gun.

Preparing Your First Cup

Just like any espresso machine, you�ll want to grind your coffee and place the appropriate amount in the filter basket.

 
You can then tamp down the grounds with the plunger unit.  The amount of coffee you use and the pressure with which you tamp it down will determine how much pressure is needed to force the water through the grounds and out of the machine.

To operate, the two halves of the machine are then screwed together and filled with water to just below the bottom seal.  The plunger is inserted and the entire unit is loaded into the caulk gun.

How It Works

A typical espresso machine circulates water past a radiator, heating it to just under boiling temp.   The water is then pumped through the coffee at about 12 atmospheres of pressure.  When the coffee exits the system and depressurizes, small co2 bubbles form and rise to the top, creating a reddish-brown foam.

With this machine, you�ll heat your water seperately and then just pour it in.  I highly suggest you pressure test the unit for leaks with cold water before trying a hot water run.  You are the pump, so you will control the pressure in the system.  It�s all dependent on how hard you tamp the grounds and what rate you force the plunger through.  You probably won�t be producing 12 bar and I double.. no.. triple suggest you pressure test the system if you are even going to attempt that kind of pressure.

It takes about 20 seconds to produce a couple shots of espresso.  It�s black, strong and, surprise, it tastes like an espresso.  You probably wont be winning any taste-test competitions, but the hack value counts for something, doesn�t it?

[Jon Russek @ Dec 19th 2005 2:45AM]

Cool concept, but for $30 you can get a pretty nice steel moka pot which has the advantages of sitting on a stove AND never exploding hot water and coffee grinds (which stick like napalm) all over you.

[barb dybwad @ Dec 19th 2005 2:45AM]

ha! this is awesome. i vote yay for low tech, and yay for as many different vehicles I can use to prepare caffeine as possible. nice work, Jason!

[ernie @ Dec 19th 2005 2:45AM]

For a little less work and $30 more dollars, you could probably retrofit a beef jerky gun

http://www.leeners.com/beefjerky.html

[TAZ427 @ Dec 19th 2005 2:45AM]

Jon, you're going for the expesive stuff. $12 stove top espress machine will make just as good as the $30 chrome finished one you're talking about.

Another Added benefit - no PVC residue flavoring.

TAZ

[Chris Gregg @ Dec 19th 2005 2:45AM]

Oh come on -- no crema! I might have actually tried this out if I could see a bit of crema in that cup there. I'm going to be skeptical about the "it tastes like espresso" until someone makes me a cup...

[Plinkerton @ Dec 19th 2005 2:45AM]

Definitely not made with steam. If it is, every espresso machine I used for the few years I worked in coffee shops was broken... :)

Moka pots are great, but if you get a plain aluminum one, it will taste like aluminum. I think it's definitely worth the extra to go with stainless steel, or at least plated.

I love me some espresso...

[John Rose @ Dec 19th 2005 2:45AM]

"It�s perfect for backpacking! There�s nothing like brewing a shot or two of espresso atop your favorite 14er� so I�m told."

I was at 12k last Nov in the Sangre De Cristos here in Colorado hunting...
Not sure what you've been told about life at 14k, but it's darn hard to even light (match or lighter) a cigarette at 12k, let alone 14k. Heating up water would probably take forever.

However, that's a great invention that I'll have to try next time at camp.

-John

[loner @ Dec 19th 2005 2:45AM]

#4: "Let's not forget the value of the time that you spend hunting down the parts and piecing the whole thing together. Labor costs always seem to get missed out, don't they?"

Carmi, Carmi, Carmi. Please look up the terms "DIY", "hobby", and "leisure time". Most people don't get paid during their leisure time, even if they wanted to. By doing these projects during your leisure time, you don't lose any revenue, therefore the project carries no "labor cost".

[Christian Cantrell @ Dec 19th 2005 2:45AM]

What miserable timing. Today is my first day of giving up espresso, and now I run into this. How long do the headaches last?

[Thayer @ Dec 19th 2005 2:45AM]

Personally I'm a tad reluctant to drink a liquid which has been passed at high temperature over plastic and sealant but maybe I'm funny that way.

[Bear @ Dec 19th 2005 2:45AM]

notwithstanding the horrid looking liquid in the cup, i applaud the ingenuity used to create the brewing device.

[JMM @ Dec 19th 2005 2:45AM]

Another vote for the stove top Moka in stainless - no alumimum taste. And, yes they do make a similar one for backpacking also. I also prefer it to the french press. The only person I know who would like this Caulkolatte is a buddy who thinks everything should be made with PVC & duct tape.

BTW - What idiot designed the big, expensive machines anyway? Obviously they never tried to work one when caffiene deficient in the morning.

[charlie @ Dec 19th 2005 2:45AM]

Why not just buy one of these?

http://www.edirectory.co.uk/pf/pages/moreinfoa.asp?recordid=1760103&cid=880&afid=88888

[jason striegel @ Dec 19th 2005 2:45AM]

hah! sherwin, thanks for spreading the love. it's always touching to hear from you :)

in case anyone is thinking of making something like this, it's a proof of concept and there is definately room for coffee loving hackers to improve on the design.

things to improve:
- looks: can you think of a prettier way to pressurize water than the caulk gun method?
- materials: pvc was easy to find and work with, but perhaps there is a better material suited to the task.
- function: higher pressure would be desirable.
- efficiency: something a bit easier to use and that required less water per pull would be desireable.

so consider it an assignment. come up with a cheap way to make your own espresso machine, attack one or more of the issues above, send it in to hackaday, and i'll make sure to post it.

...and if you are successful, someone will call you an idiot for making cool-ass crap :)

hack on!

[jason @ Dec 19th 2005 2:45AM]

Poly Vinyl Chloride? You've got to be kidding. Left alone, it will leach toxic chemicals. But you're heating it up. And when PVC burns it emits dioxin and heavy metals.
Ick.

[HardwareLust @ Dec 19th 2005 2:45AM]

While I applaud the OP's obvious energy and inventiveness, I just don't see the point when a pefectly good Bialetti stove-top espresso maker that can make a perfect shot is ~$15 + shipping.

But, if I'm ever stuck in a warehouse full of PVC pipe, and I have some espresso grind in my pocket, I know what I can do for entertainment in the mean time!

[CrystalGeyser @ Dec 19th 2005 2:45AM]

At my local bank, Bank of America, they give a free espresso machine for opening new checking accounts. Opening accounts are free and theres not minimum amount you need to deposit.

[Carmi @ Dec 19th 2005 2:45AM]

Let's not forget the value of the time that you spend hunting down the parts and piecing the whole thing together. Labor costs always seem to get missed out, don't they?

Carmi
http://writteninc.blogspot.com

[J @ Dec 19th 2005 2:45AM]

Espresso is not made with hot water. It is steam that is forced through the grounds.

[Kwang @ Dec 19th 2005 2:45AM]

Next time on How-To: How to make a bong.

[alex koesen @ Dec 19th 2005 2:45AM]

This is by far the best way to impress your friends on a birthday party.
Make sure you are wearing full protection gear and give all the coffee away~!

[lizocka @ Dec 19th 2005 2:45AM]

I can't stand beer in cans, partly because of the alum. aftertaste. The same goes for pies that you can buy in the alum. tray. And I also don't drink bottled water - once it warms up to room temperature I taste plastic. This qualifies for a Darwin Award.

[Snoboy @ Dec 19th 2005 2:45AM]

Espresso is not made with steam J. It is made with water that is just below the boiling point.

Also, most espresso fanatics concur that a pressure closer to 9-10 atm is ideal. Most pumps produce 14-15, but they are regulated down to make better coffee. I wonder if maybe you can get that kind of pressure with a caulking gun...

[Ugh @ Dec 19th 2005 2:45AM]

Oh please, this isn't espresso, where's the crema?

Gosh, just halve the water in a french press and you'll accomplish the same thing.

I can't believe somebody wasted their time with this.. two thumbs down.

[Sherwin @ Dec 19th 2005 2:45AM]

If you pull that out at a party your friends will think you are a fucking idiot for making that crap. Which you are.

[eucalyptus @ Dec 19th 2005 2:45AM]

how about very very strong coffee made anyway you know how?? very strong. very small amount.very very strong?

[Phungus @ Dec 19th 2005 2:45AM]

Crap....I just ordered a $1500.00 machine. I could cancel my order and make 50 of these!

[richard @ Dec 19th 2005 2:45AM]

Portability? Doesn't get any better than this:

http://www.quickspice.com/cgi-bin/SoftCart.exe/scstore/cookwarecoffeemaker.shtml?E+scstore

Let's not even think about the excellent taste that PVC would impart on coffee... or whether boiling water could cause PVC to release anything dangerous into the mix. MMM.... Dioxyns....

[John @ Dec 19th 2005 2:45AM]

Pretty neat idea, I'll have to try this. The caulking gun is very inventive. I wonder if you could actuate the piston via a ram driven by a paint guns CO2 valve and tank. You might not want to be near it when your testing it but it would make for one hell of a fast cup of coffee.

[Nick @ Dec 19th 2005 2:45AM]

Mmmm... I personally would not be putting such instructions on my website, as people have died from drinking hot water from PVC piping, it can be that toxic (well the glue commonly used can be). This is just not a good idea IMHO - white PVC is not rated for hot water. The legal implications of this page are a bit frightening.

[David @ Dec 19th 2005 2:45AM]

PVC is well known to cause carcer thats why its only used for waste water pipes.

[jason striegel @ Dec 19th 2005 2:45AM]

i'm not a chemist or a plumber, so take my advice with a grain of salt.

david, i believe pvc is approved and commonly used for potable cold water, though i believe it is not approved for hot water due to joint failure problems. cpvc is probably the correct 'similar' material to use for this application. you can find it just as easily and it has the same specs (looks like pvc but beige).

the manufacturing of both products is extremely nasty and not a 'green' process and it's disposal poses an environmental hazard, so that's a really big downside. i'd like to see someone come up with a better solution that involves a more eco-friendly and easy to obtain material.

oh, and you absolutely do not want to burn either product.

[Keller @ Dec 19th 2005 2:45AM]

Next up: How to make a blender out of a coffee can, a fork, 3 rubber bands, and an exercise bike!

[fran liscio @ Dec 19th 2005 2:45AM]

i just like the idea of a product made with a caulk gun and a co2 cartridge. you could probably make seltzer with it too.

[Mark Lauzon @ Dec 19th 2005 2:45AM]

Its is kinda of a joke...its funny...what is wrong with half of you people. It is funny!

Dorks!
"umm you know that poly cloride leaches heavy metal"
"the manufacturing of the stuff is not a green process"
"i'd like to see someone come up with a better solution that involves a more eco-friendly and easy to obtain material."

Dude: Heavy metal is a style of rock music...if he can make that thing play some sammy haggar...more power to 'em

now go shoot yourself

[koz @ Dec 19th 2005 2:45AM]

Try using CPVC, chlorinated PVC pipe. That's typically used for pressurized water supply lines, maybe it doesn't leach stuff into the water like standard PVC.

[doug the chemical engineer @ Dec 19th 2005 2:45AM]

Hey, be extra sure to flush out all the PVC Cement with, like, really really hot water...the solvent in that stuff is, like, toadally double ungood for your liver and kidneys...and for your chances of having, like, normal offspring, dude. Read the label. Just breathing the fumes that rise while you'r gluing the PVC together can be hazardous to yer health. Thats one reason the white pipe with cemented joints is used for sewage and drain pipes, not for drinking water.

[CrystalGeyser @ Dec 19th 2005 2:45AM]

Hey I didn't know we went back to a time where electricity isn't avaiable!
Theres one device this guy forgot to invent, a coffee grinder.

[Jason Green @ Dec 19th 2005 2:45AM]

I'm sorry, but this is just stupid. When exactly are you going to bust out the caulking gun and make some coffee? He even states that you wont win any taste tests. In other words: it tastes like shiat.
Sure, there's the DIY "I made this" factor, but I think you realistically just need to shut up and go get a proper cup of coffee.
Or... sit there and drink your stank brew while sitting proudly next to your CAULKING GUN. The choice is yours :-)

[A @ Dec 19th 2005 2:45AM]

Lemme get this straight... I spent years learning how to make my backpack lighter, and now I'm a gonna carry a caulking gun? Little hint folks - Media de Oro, best instant espresso ever. Good, dark, STRONG. Only instant I will touch.

I'll give you a point for originality though. Find me some food grade PVC and I might just put this in my car for road trips and the wierdness factor, but not in my pack.

[Sherwin @ Dec 19th 2005 2:45AM]

I wasn't calling you an idiot. I was talking about anyone who whips that out at a party in hopes of impressing everyone.

[Wasim @ Dec 19th 2005 2:45AM]

I'm not really a coffee person I guess it is an acquired taste. But strangely I do like the smell of coffee.

Why am I posting?

Just wondering do any of you guys need coffee in the morning to get yourselves going? Not taking the piss - I find it interesting that some people need that caffeine fix. That 'I couldn't live without coffee' feeling.

I guess not being a coffee person I wouldn't understand - so I'll go away now...

[Lagart0 @ Dec 19th 2005 2:45AM]

Hey guys, I have a better idea, we can use the PVC and CAULKING GUN for making just everything, from IceCream to Ketchup... anyone else with some "nice" ideas like mine?

[kate4114 @ Dec 19th 2005 2:45AM]

Whatever you say, guys, i still think that this is a really really cool idea. Even though i'm not a coffee drinker, from a college kid's perspective, it's a really cheap, really easy way of getting a caffine fix in the morning, and in the end, isn't that really why people drink coffee?

[Too funny @ Dec 19th 2005 2:45AM]

You've almost made an old fashioned manual, piston powered espresso machine, all that's needed is a water line to feed into it and you have just recreated the original espresso machine.....

Where's the crema....come on folks, this is some guy tinkering in his shop, should he have added a frother and hot water spicot as well as made it do one of those cool patterns in the top of the cup??? Give me a break....

I hope to see you create a new generation, this time use only metal parts, the pvc has a tendacy to ommit bad tastes until it's been broken in.

[Trueman @ Dec 19th 2005 2:45AM]

It is my diy espresso machine, aka Truesso.
Check it out.
http://ssel5.phys.nthu.edu.tw/~trueman/photos/Truesso/

[ashby @ Dec 19th 2005 2:45AM]

cpvc is better...and way less toxic, but if you're doing this much, why not wrap a little bit of copper pipe with foam insulation and have yourself a mobile hammecher-schlemmer?

Or however the hell you spell that.

[PatboyX @ Dec 19th 2005 2:45AM]

people seem to be missing the point: obviously, we could get an esspresso machine that was decent for about the same price as making this and it would take less time.
but wheres the fun in that?
who doesnt want an esspresso gun to show off...and be able to say they made it?!

[light @ Dec 19th 2005 2:45AM]

Thankfully I am not the only person who realizes the health risks of passing pressurized hot water through pvc pipe. As someone else pointed out also that the glue it self is enough to partially destroy liver. this is the reason that no one uses PVC for potable water. I will say though that the concept is very good and as 47 said, that it might be a good idea to try to mimic this in copper.

[knewman @ Dec 19th 2005 2:45AM]

That espresso looked terrible, and PVC is poison. This is a terrible idea.