Buyer's Guide to the Gaggia Achille - Page 7

[cannonfodder]

I started with Dave's posted routine. Although the pressurestat setting is lower than Dave's (1.25 bar? I didn't write it down), the flush routine was nearly the same: About two full strokes

My original pstat setting was 1.45 and it took 3 pulls to flush. I lowered the pstat down to 1.2 bar and went to a two pull flush. I think the key is that you need one full pull of the lever with no flash boil during any part of the pull.

[cannonfodder]

The Achille does not have a 3 way valve and hence suffers from the dreaded portafilter sneeze. If you have never had the pleasure of painting your kitchen with coffee you are lucky, it truly is a mess.

The Achille appears to hold pressure longer than my Factory after a shot is pulled. One of the interesting things about the group design (be it intentional of accidental) is that you can loosen the portafilter while it is still under pressure. A quarter rotation and the pressure will vent. Any water and coffee grounds will flow around and down the portafilter and drop in the drip tray.

[another_jim]

That's rather neat. It looks like they widen the PF groove just ahead of the point where the PF ears drop out of the slots so that the pressure seal is broken while the PF is still locked in, and the water leaks out without blowing the grinds all over. Given the problems of creating an exhaust valve on a lever machine (one would have to mount a manually operated valve), this seems like a good low cost solution.

[cannonfodder]

That shot had sat in the machine for a bit and it was still under pressure. The down side, if you use the same trick right after a shot, it pushes grounds into the group lugs. You really need a group brush to scrub it out after each session but that is a small price to pay to keep from blowing espresso grounds up your nose.

[cpl593h]

That's pretty well thought-out.

I noticed in the last video that the portafilter seems much deeper than a typical OEM 58mm PF. Can it accommodate a triple basket?

[cannonfodder]

I do not have a triple to try. If someone wants to volunteer one up for the test I will sure give it a go.

[cannonfodder]

Shot of Espresso Havana from Paradise Roasters

[cannonfodder]

Shot of Espresso Classico from Paradise Roasters

[HB]

I noticed in the last video that the portafilter seems much deeper than a typical OEM 58mm PF. Can it accommodate a triple basket?

I do not have a triple to try. If someone wants to volunteer one up for the test I will sure give it a go.

Just tried it... a triple basket fits in the stock Gaggia portafilter (barely).

[cannonfodder]

Just tried it... a triple basket fits in the stock Gaggia portafilter (barely).

Darn, I was hoping someone would send me a freebie

[cannonfodder]

In case no one noticed, I spun off the double spouts on the portafilter and put my single spout from my Faema on for the above videos.

[peacecup]

Dave, when you get a chance to post another video can you leave the shot sit for ~1 min the end of the pour to see how the crema develops and settles?

PC

[cannonfodder]

Dave, when you get a chance to post another video can you leave the shot sit for ~1 min the end of the pour to see how the crema develops and settles?

PC

One min, my shots usually last about 30 seconds then I am left the lingering reminder of the visit and wonderful aroma that fills the house. Sure, I can let it sit and stale

I noticed in the last video that the portafilter seems much deeper than a typical OEM 58mm PF. Can it accommodate a triple basket?

I measured the portafilter. My calipers are too wide to measure the inside so I had to go with an external portafilter measurement and guess at the base thickness. I get 1.02 inch give or take .01

[HB]

The discussion of the measured brew pressure results in First ever lever pull pressure mod has been interesting and enlightening. I was surprised to see how difficult it is to maintain a consistent pressure! I've never claimed to be a lever maestro, but since the Achille has a 58mm portafilter and I have a pressure transducer hookup for the thermofilter, tonight I decided to calibrate the old arm with the help of some high-tech toys.

Pushing down the lever against the even flow of the thermofilter doesn't give the same realtime extraction data as the above modification, but it does give valuable feedback about the resulting brew pressure for a given lever pressure. The first of the series is a "blooper" because I was watching the display while I pushed down:


Not looking at the pull = brew pressure all over the map

Lesson #1: Pay attention.

The best angle of attack required that I move the machine down to table height, otherwise my lever pressure shifted as the angle of my arm changed, as demonstrated below:


Starts high and ends low as I shifted gears

Lesson #2: If you're short, consider moving the machine off the countertop.

I noted that the pressure profile was most constant when I used my shoulder weight and didn't exert myself too much. Instead I adopted a fixed arm angle and used upper body weight to supply pressure. The profile below is after more than a dozen attempts and was the flattest of the series:


Closer to 8 bar than 9 bar

Lesson #3: If you want high brew pressure lever shots, upper body strength isn't the issue, it's height and upper body weight.

PS: I don't have an analog bathroom scale, but I would estimate my downward pressure at around 30-40 pounds.

[mogogear]

Lots of reporting and tons of great questions..... my hat is off to you Dave for a really comprehensive and detailed report. Your accommodation and anticipation of many questions is really appreciated. I merely sat back and read and had all my wonders answered. Your help is appreciated too Dan.

Thanks for all your effort.

[cannonfodder]

Glad you are enjoying it.

I did a video a couple of days ago that I have not posted yet just to show I apply pressure to the lever. I start with some arm pull pressure and quickly lock my arm and roll my shoulder and bend letting gravity instead of muscle do the extraction. When I am home I will upload it.

I also did an Achille shot and let it sit and stale for a minute so the crema has totally settled. Just for comparison I did another shot, same grind/dose/basket in my Faema and let it sit and die a slow death. The two are very similar but the Faema had a little more persistence in the crema at first but eventually went as flat as the Achille.

Watching those two shots die a slow death was heartbreaking because they looked good.

Dan has more of the tech toys so the thermometry will be coming from him. I may go ahead and invest in a couple of gadgets myself once we have completed this. I always wanted to be able to say 'Let me whip out my pressure transducer and we will test it'.

[peacecup]

Dan's pressure profiles are great. I've found that I really like having my spring lever on a relatively low surface as well. Rather than pulling the lever down I push it down with body weight. I've also found that a lower surface makes tamping much more consistent.

Commercial spring levers are sometimes mounted relatively higher. I guess that once the barista pulls the lever, which can be done with arm strength, the spring takes over and provides more consistent pressure.

PC

[hperry]

On my commercial lever the spring does the job and it is a little easier to pull the shot if the machine is somewhat higher up. While with some commercial levers (mine and the Conti come to mind) it's possible to accelerate and retard the flow, I seldom do. I prefer to control with distribution and grind.

[cannonfodder]

Dave, when you get a chance to post another video can you leave the shot sit for ~1 min the end of the pour to see how the crema develops and settles?

PC

As requested, here are two videos of two perfectly good shots dying a slow staling death. The first is from the Achille. For comparison, the second shot (from my Faema two group) was moments after the first using the same bean, the same grind, the same dose and the same tamp.

Achille


Faema

[cannonfodder]

I have talked about the Achilles steaming abilities in previous posts. I have shot video for everything else so why not froth up a 6oz pitcher of milk and then watch the microfoam separate out of the milk. This was using the frothing extension that Todd from Whole Latte Love sent me to try out. Full sized video is clearer but also 13 meg.