For those of us that would like a good cup of coffee but don’t want to put up with the ‘burnt butt’ taste of Starbucks and don’t have a decent coffee shop nearby, we’ve had very few options. Most of us have been made to suffer with an el-cheapo espresso machine. [Joe] sent in a great build that improves these el-cheapo models and brings them up to the quality we would expect from their more expensive brethren.
For the best pull from an espresso machine, the great [Alton Brown] says 200° F water must be forced through the grind at around 10 PSI atm. [Joe]’s espresso machine can’t build up pressure because the heating element is only active when the lever is in the ‘brew’ or ‘froth’ position. To build up pressure in the water reservoir, [Joe] simply added a pressure gauge to the frothing attachment. When the gauge reads the necessary 10 atmospheres, just move the lever over to the ‘brew’ position and enjoy a nice cup of espresso.
[Joe] has already tested the pressure relief valve of his espresso machine. With the gauge in the way, [Joe] can’t make use of his frother, but a secondary valve could easily remedy that. [Joe] hasn’t published his espresso hack anywhere, but he did email us some pics of his build. We’ve embedded them as a slideshow after the break. Check out the pressure gauge on the frothing attachment and the pressure relief valve below.
[slideshow]
man those espresso machines are still so darn expensive.
nice hack, I’d do almost anything to get a good affordable espresso machine.
Ahem… not 9 psi, 9 bar. There’s a small difference of around an order of magnitude. :)
It’s not going to happen. That machine is what is derisively referred to as a “steam toy”; the pressure is going to wildly fluctuate throughout the extraction.
In addition, the desired pressure is 9 atm (gauge; 10 atm absolute), not 10 psi, so it should be at 130psi (gauge).
You’re not going to be able to extract reasonable espresso with that machine without adding a pump.
EXACTLY. This sadly ubiquitous piece of garbage is an espresso machine in name only and cannot be modified into a proper espresso machine without a pump as well. Are there any extraction videos or shots showing the pressure gauge at 10 bar? Of couse not– the pressure will drop right away when brewing, when a good machines’s pump would start running.
People looking for inexpensive machines should keep their eyes out for used Brevilles or Starbucks Barista models– there are a lot out there, but many people who buy them don’t realize the work required to extract a good shot, so a lot of them go unused. They’re actually very capable little machines! Also any used Gaggia should be fairly cheap and reliable, though there just aren’t as many out there.
pressure relief valve in cap opens at 55psi. as pressure drops when brewing, more water boils to make up pressure until temperature drops back to 212F. still not official espresso, but much better than the 2$at goodwill machine did before.
pressure relief valve on cap opens at 55 psi. i bought it for 3$ used at goodwill.
Aeropress! It’s cheap and brews the best coffee ever. No gauges, no fancy steam, just great coffee.
Or it’s old-skool cousin, the french press. freshly roasted, freshly ground beans. 200 degree water. four minute steep. That’s all you need for an excellent cup of coffee.
Personally, I grind my beans fine, because that maximizes flavor and I don’t mind the sludge. Actually, sludge (with a little extra sugar) is my favorite part.
If you like the sludge you should definitely go for mocha/Turkish coffee.[WP] I drink mine during midday break. Takes 2-3 min to prepare, tastes great and gives you the biggest whack of caffeine you can get :D
I pop coarse grounds in my french press and let it sit for 3 min and like the results, so I wonder how fine your grounds are. I can’t really imagine that would get great results, but I will try that.
Mmmmmm tasty lead filled brass fittings.
I have almost identical model. This is how I like my coffee @ YouTube
I’d bet the brewing temperature and pressure are about the same. There’s just no way to get decent crema with the thing. I am planning on improving mine or building a new one. I wonder if that modification produces decent crema.
‘burnt butt’ taste of Starbucks
Why I call them “Charbucks”
9 BAR!
My understanding is that 4 was generally considered best.
Also 9 bar contained in a cheap coffee machine… careful, steam is INCREDIBLY powerful.
at 10 bar, wouldn’t the water temperature be 180 C, almost double than recommended, effectively burning the coffee?
so 9 bar ar 210F is what we want. household water psi is usually around 6 bar so that is getting close.. we could force the hot water through with hot tap water with a faucet adapter… or we could use compressed air at 130 psi (9 bar) to push through the coffee ground’s puck. water cooler refrigeration pumps are fairly small.. just need a regulator and a releif valve and a new port into el cheapo water tank…..