Tim, can you swivel your steam wand around so it shoots the water back into the reservoir? Mine doesn't reach unfortunately...

Henry

No...

But I tried!

This sounds somewhat similar to what one of the elektra microcasa a leva owners was doing to control the shot temperature for coffees that are best at the lower end of the temp spectrum. I can't remember what post it was, but I believe it was Trish that wrote it. Anyway I plan on trying something similar to this when my pavoni arrives to see if it can be adapted for a lever. I believe that Trish was using the boiler pressure gauge by running the steam to bring the pressure down to around .4 bar. Once it was there she closed the steam off and pulled the shot. Interesting idea. We'll see about the adaptation. Thanks a ton Tim for another really wild thought.
Lynn

Anybody else finding this useful?

I like it most for the simple reason that my machine doesn't have an OPV and too fine of a grind can get... messy... but with one hand on the steam valve I've turned several potential explosions into melted coffee butter ristrettos.

It's also nice to follow the Pressure Profiling thread knowing I at least have the potential to imitate Greg's findings!

I'm going shopping for a pressure gauge next week and also want to put another steam wand upstream from the boiler...

Henry

Tim, great idea. I actually started doing exactly the same thing for a little while with my crazy contraption of an espresso machine, which has a very similar design. I opened the steam valve a little for a few seconds and watched the pressure ramp up on the gauge until I saw the espresso and then I closed it off. I didn't really get a chance to notice a definite improvement but I think the shots were slightly smoother in general. The only issue with this is that more cold water has to be pumped into the boiler which might have an impact on the temperature stability. Great idea though and thanks for sharing.

Good Lord! What did that Frankenpresso machine start life as?

Haha. It used to be a La Pavoni Club Combo, similar to the Gaggia machines. I made my PF naked, added a PID, completely revamped the plumbing to include a pressure gauge and a relief valve, uh.. and it didn't exactly fit under the hood when I was done so I left it off. It served me well until I got my Wega working and now it's just sitting in the garage.
It started life as this:

I put a pressure gauge and a valve on the cold water side of the boiler.

This was the second shot from this set up, I tried to keep it at 9 bar (as shown on the gauge) then let it off towards the end.

12 grams of ~50/50 Brazil + Mandheling

The espresso was full of flavors I've never tasted before, really an experience! The aftertaste was not so nice, however, which could be because of my continuing distribution problems.

Now that's kinda cool. I like it! I see that you too enjoy the challenge of maximizing the capability of a machine regardless of the amount of effort required to do so. It's analogous to porting the heads, replacing the pistons, camshaft, and headers, installing a supercharger, reprogramming the ECU, upgrading the exhaust, adding an intercooler, a hood scoop and a nitrous oxide injection kit to a 1.6L Honda Civic LX.

oofnik wrote:to a 1.6L Honda Civic LX.

sigh... it's true!

I just pulled a great shot with 15g and ~30sec extraction... wow! I've never managed to do that before!

Henry