Stove-top bike-pump modification

#1: Post by **vtspresso** » September 8th, 2013, 10:25 am

Hi all,
For picture/video, check out:

I'm new to the homemade espresso world, but after learning to enjoy really good espresso made by others, I realized how dissatisfied I was with my cheap stove-top maker. I did some research and found the ideal temperatures and pressures for espresso, and realized that the stove-top maker was failing miserably on both those fronts (way too hot, far too little pressure).

So, first I got rid of the stove part and attached my own pressure source (a Coke bottle with a bike-pump hookup). Now I can precisely control the temperature & pressure to the degree/psi. All I can say is that it makes an incredible cup of espresso.

Cheers!
Taylor

#2: Post by **Beenbag** » September 8th, 2013, 6:04 pm

..I think you are pushing your luck if you are putting 7 bar pressure into that coke bottle !

#3: Post by **TomC** » September 8th, 2013, 7:39 pm

I think you should be commended for your ingenuity! Especially if it makes a beverage you enjoy. I just hope you're allowing your home roasts to rest before using them.

September 8th, 2013, 9:09 pm

I was worried about that initially, but all the sources I could find indicate that Coca-Cola representatives say all their bottles are rated to at least 150 psi (a little more than 10 bar) - an industry standard. There is also evidence that the smaller bottles can hold higher pressure still with some sources saying up to 200+ psi.

Thanks for your concern though!

#5: Post by **Beenbag** » September 9th, 2013, 2:31 am

As an "industry " technical guy i can tell you the pressure requirement for those bottles is 6 bar (minimum).
They will hold beyond that , but remember that is for a fresh made , unused, undamaged, bottle.
just be careful, when they let go at that pressure, it can do damage !

#6: Post by **tamarian** » September 9th, 2013, 3:36 am

This is so simple, it is beautiful.

#7: Post by **Randy G.** » September 9th, 2013, 11:43 am

Why not use a PID-controlled small, portable electric air pump?

Seriously, trade out the coke bottle for a paintball gun bottle.

#8: Post by **Aaron** » September 12th, 2013, 2:21 pm

Besides your homemade bomb Coke bottle that was already commented on, that is a cool setup!! Cheap and ingenious!

#9: Post by **Godshot+1** » September 13th, 2013, 10:45 am

Great stuff, love it!
Could you post the exact parts you used, besides the bialetti and coke can?

September 13th, 2013, 12:08 pm

Moka pots aren't designed to see 9-10 bar.

Surely, once fatigue sets in you WILL blow that plastic bottle, but I would also be cautious with that moka pot.

You are pressurizing it through the pressure release valve....
Surely that should raise a few yellow or red flags.