Brew Pressure in a Spring Lever

[SJM]

I'm wondering what you know about the pressure profile generated by a spring lever, hopefully by a SAMA, but that might be getting too picky.

I have this suspicion that it is lower than the 9 bar that I've set my Classic to, and I've been wondering what effect it would have if I were to lower the pressure on the Classic even more...

Susan

[JojoS]

AFAIK, 9 Bar brew pressure is optimal for vibe pumps. Rotary pumps can go as low as 8 or 8.5 but it will be fun to play around with it. Who knows if a particular roast profile will taste better when pulled on a Gaggia Classic at lower than 9 Bars unless we try. 

[John F]

The tires on a truck are bigger than tires on a motorcycle.

 

[milowebailey]

The tires on a truck are bigger than tires on a motorcycle.

 

e
+1


And an IPA is hoppier than a pale ale.  Totally different animals.

[ecc]

Please don't ask me why I have this Slayer link bookmarked, but it does have a neat graph.
http://www.slayerespresso.com/2007/12/10/lever-espresso-extraction/

[SJM]

So, are you telling me that all the modding in the world isn't gonna make the Classic produce as well as the SAMA?   

Well.....I'm probably going to keep trying anyway.

[SJM]

Please don't ask me why I have this Slayer link bookmarked, but it does have a neat graph.
http://www.slayerespresso.com/2007/12/10/lever-espresso-extraction/

Thanks Todd.
I will read that ......after a latte :-)))))

You posted it just as I was posting above.

[John F]

They are different shots.

You could remove the pump...

[milowebailey]

This quote from the Slayer blog pretty much sums it up.


So, to summarize, we have hotter water hitting the coffee at a lower pressure for pre-infusion. Following by a slightly higher brew pressure to start which gradually and consistently decreases, along with the brew temperature over the shot extraction all with water that is on 100% contact consistently & evenly over the shot. Easy to see why a lever shot tastes nothing like a shot from a pump machine.


But don't ever give up trying Susan.... You can only improve the Gaggia.... Just as the OPV and Silvia steam wands did..... I applaud you for trying!!

[SJM]

Nah, I'm not going to stop trying.
I think my next thing is going to be to install a dimmer on the pump....

Stay tuned....
Today I am going to roast, however -- three batches on the Behmor -- with only a trip to take the cat to the vet to interfere....

Susan

[John F]

Dimmer on the pump...wow!

I predict some wild fluctuations with no ability for ANY stability. It should make for a very fun test.  Frustrating but fun.

[SJM]

This guy, AndyPanda, has done some very interesting work, and he seems to have gotten very good results trying to emulate a lever with a dimmer. 

http://coffeegeek.com/forums/espresso/machines/580293

Susan