IN General, I wait 1 minute before removing the P/F. Minimal pressure left in the group at that point... My Factory runs at about 0.8 bar up to 0.95+ (the needle sits in between 0.95 and 1.0). One thing I've found is that, with the pressurestat setting that I have, my standard "Flush 3 seconds, wait a bit and then flush 2 seconds before pulling the shot" gives me a FIRST shot that's a bit overheated (not much, but a bit). What I'm CURRENTLY doing is "3 second flush, remove the P/F and 'cool' it under hot tap water" then pull a second short flush without the P/F in the group. THEN I lock-n-load and pull the shot. (This is always for the first shot of the session). When I do that, I'm getting a pretty good shot, first pull. The previous Factory cycled between 0.7 bar and 0.9 bar and would always do a sour first shot (not a lot, but sour). I'm able to pull a pair of doubles this way and they both taste the same (to my poorly trained palate).

yeah, i was thinking i might go a little higher...but i hit a tight spot on the pstat and decided to leave it there for now to see how it works...
while reading the forums i thought i read that most of the other lever machines run close to a full bar of pressure...alot higher than what mine was running.
mine is definitely better now than when the boiler idles around .5-.6 bar...yuck. i just waited to makes sure i got used to pulling nice shots with it before i started making fine tuning adjustments.

piwonka wrote:yeah, i was thinking i might go a little higher...but i hit a tight spot on the pstat and decided to leave it there for now to see how it works...
while reading the forums i thought i read that most of the other lever machines run close to a full bar of pressure...alot higher than what mine was running.
mine is definitely better now than when the boiler idles around .5-.6 bar...yuck. i just waited to makes sure i got used to pulling nice shots with it before i started making fine tuning adjustments.

Agree wholeheartedly! I've not yet modified my PStat setting (was thinking of going a touch lower, but it's drifted down just a small amount with use). I'm still working on understanding this beast! VERY nice espresso coming out (currently using some Sumatran from CCC with a roast date of 22 Feb) but I AM a "tinkerer" ! SO I'm sure I'll be "tweaking" it at some point!

i'm using some italian espresso roast from anderson's coffee here in austin. it makes a pretty good shot. but the beans got old as i was sick for a week and wasn't even drinking coffee...they are maybe 2-3 weeks old i guess. i also ran out of good water so i have used tap water a few times. that may have contributed to the sourness i guess...i don't know. but i have noticed the bitterness with almost all the beans i've used. all from local roasters.

i may have gotten lucky with my pstat, i don't know.
what i did after i opened it up, was take an old toothbrush with the bristles cut a little shorter to amke them stiffer (used to clean older bike parts usually ), well that brush dipped in a little simple green then shook off to keep from dripping it on the wires and stuff, was used to try to clean the loctite off.
it didn't look like it made any kind of difference, so i took a rag in my fingers and then turned the adjuster kind of firmly. it broke free but would only loosen up. so i took the brush with just a bit of wd40 instead (again shook off), and brushed the loctite again. then i tightened the adjuster down on the loctite and it went a little further down...so i backed it off some and then tightened it back down again...it went further down still. i managed to get about 1/3 to 1/2 of a full turn out of it and left it there to see what it did. so i guess about 1/3 or a little more of a turn equals about .25 bar or so...

Bitterness CAN be caused by EITHER a grind that's a bit "loose" (which causes a fast extraction) or, as I discovered, can be caused by a tad warm group (I was getting not the ashy taste of a typical over-temp pull, but a bit of a stronger extraction of some of the bitter tastes. Extraction was not "quick", but I was still seeing some increased bitterness). Cooled the P/F by running it under hot water from the tap and the extraction hit the sweet spot right away! The sour taste is USUALLY a cool group, but what you're interpreting as sour COULD be the acidity of the bean/blend. I found that with a very light roast that I was having problems with... Went a bit warmer and it was a great shot! Only talking from my experiences (and my very limited palate training)... YMMV.

EDIT: when I say a bit warmer, I'm talking of increasing the warming flush before making the shot. I've not yet had a chance to "instrument" the group on the Tin Man! Am THINKING of ways to do that! but not there yet!

thanks for that info.
i almost always run the pf under water to clean it out between shots but haven't really messed around with varying the time i warm the pf before each shot...hmm. more stuff to try huh?

as far as temping the group. how accurate are those electronic temp readers that you can just point at stuff and it reads the temps. i know car people use them to gauge how hot their tires are getting...

A good one can be quite good and accurate (but not to 1c or so, that's asking a bit much). Also, you're measuring the outside, radiating surface where the temperature you're really interested in is INTERNAL (and flowing!). I've got one of those and use it often looking for hot spots on "things", but I've never used it in the espresso making process. It's good at what it does, but I can't point it at what I'm interested in!

piwonka wrote:as far as temping the group. how accurate are those electronic temp readers that you can just point at stuff and it reads the temps.

I have done a bit of experimenting with this recently.

Most infrared thermometers only work on non reflective surfaces, so getting a measurement straight off the chrome is not an option. I place a strip of blue painter's masking tape on my grouphead and take measurements off of that. I have always removed the tape right after finishing my session, and it comes off cleanly with no residue left behind.

I have two infrared thermometers, both inexpensive models: a Thermoworks TN-1 with 1:1 optics for short range measurements, and another with 12:1 optics and a laser pointer, intended for longer ranges. The TN-1 works well, as I can easily hold it just fractions of an inch from the tape. My other thermometer with the laser does not work as well, as the laser is not aligned precisely enough to point to exactly the same spot that the reading is being taken from. I can eventually get the reading by moving the laser off the tape, but it's trial and error. So, YMMV depending on the thermometer model.

I have found it useful as a learning tool to measure the grouphead temperature before my shot and then correlate the temperature reading to the shot taste. I have no idea what the absolute accuracy of the thermometer is, or how the surface reading relates to the water temperature -- I am only assuming there is some correlation between the reading and the actual water temperature, and that shots taken at a given reading on different occasions are at least more likely to have similar temperature properties than two shots taken with different grouphead temperatures. My tasting results seem to bear out this correlation -- at least at a gross level -- but other than that I have no independent method of determining the relationship between the grouphead surface temp and the actual shot temp.

One useful technique I discovered during my experimentation was that I can raise the grouphead temp without flushing any water, simply by raising the lever up half way and then pushing it down again. I have found I get more predictable results (i.e. I can raise the grouphead temp to a target range with some consistency) by using N lever half pumps, than I was able to by doing a water flush for N seconds (I found it very easy to overshoot when using the water flush approach). I'm currently using 4 half pumps, which gives me a grouphead surface reading of 195-200 before the shot.

My spare portafilter came back today after being cut into a bottomless by John Weiss' friend, Brett Wilsey (if-god-wanted-us-to-go-naked-we-d-have-been-born-that-way-t6000.html). Brett did a wonderful job - absolutely flawless. Had it been done at the Gaggia factory (small "f" ), it couldn't possibly look any better!

Next will come actually trying it out on my Gaggia Factory G106. Unfortunately, this will have to wait until the weekend after next, as we're not going to be back out to the beach house until then - and that's where the lever machine "lives". (We just came back from there last night - oh well - as with so many things in life, timing is everything...)

But in the meantime, I highly recommend Brett's services for anyone who wants to have a portafilter cut!

r-gordon-7

Well, now (following our trip out to the beach house this weekend) I can officially confirm that the replacement Gaggia pf WLL sells - and which John's friend Brett so nicely machined into a bottomless - fits and works just perfectly in the Gaggia Factory. Of course, by "perfectly" I'm referring to its fit and functionality - e.g. to its utility as a learning tool - and not to the quality of my pull using it! I can tell that with the bottomless, my pulls will improve much faster than they otherwise would have, but I've still got a long way to go before they are anything to brag about...

So, in short WLL looks like a great place to find a reasonably priced spare pf for the Gaggia Factory to have made into a bottomless - and Brett is a great craftsman for a performing the "surgery" in a quality way...

(As an aside, even when not actually using the bottomless pf for the pull, the bottomless also makes dosing into the basket from the Ascaso i-Mini grinder quite a bit easier, with no pf spout to protrude into the front of the grinder while trying to hold the pf flush against the i-mini's "slippery" on/off button and simultaneously trying to "hold steady" under the chute... Even when not using the bottomless for the pull, it's nice to use the bottomless as the "basket holder" while dosing - with one hand on the pf handle, hold the pf against the i-Mini's button & with the other hand, slowly rotate the basket w/in the pf as the grinds drop out of the chute. The bottomless pf also works much better than the spouted for holding the basket while tamping. Then, when finished dosing & tamping, switch the basket back into the spouted pf for the pull, if that's the pf you want to use for the pull...)

r-gordon-7