Tamp once--tamp twice?

[IMAWriter]

I've read so many conflicting theories on this subject, my head feels like Linda Blair's!
I realize there's more than one way to skin this cat (ugh...lousy analogy)...
I've been dosing from my Mazzer SJ, with stock Anita double basket in nekked PF, about half full, gently shaking to more evenly distribute the grind, then dosing till the basket is full, to very slightly overflowing...I then finger level, N-S-E-W,, with no pressure...then I tamp with Espro to 30lbs..i actually cheat just a touch an go just over the click....I twist 360, again very little pressure, and do Chris's maneuver of turning PF over the knock box to rid of loose grind....the grind is maybe a 1/32" under the line in the basket...
get 25 sec 1 1/2 oz pours...they look good, but are still not sweet...could I be over extracting? The pours look pretty even, as I've somewhat cured my slanted tamps with the Espro...I really liked my presso 53mm tamper better, as it had guidelines....
Am I in the ballpark with my technique...all suggestions gratefully accepted!

[HB]

...they look good, but are still not sweet...could I be over extracting?

It certainly sounds like you've read, absorbed, and applied a lot of advice. I find sweetness is the last piece of the espresso puzzle to fit, and the first to fall out. You've described a lot about what you're seeing and doing, but only a little about what you're tasting. Can you give us more information about what coffee you are using and the taste versus your expectations? It may be something as simple as the brew temperature being too hot, but I don't have enough information to hazard a guess.

[IMAWriter]

Can you give us more information about what coffee you are using and the taste versus your expectations? It may be something as simple as the brew temperature being too hot, but I don't have enough information to hazard a guess.

I've tried Ambrosia, Malabar Gold, and my own blend...40% Brazilian, 20 Harar, 20% Guat, 20% Sumatra Triple Pick Iskandar
What I taste is a "sharpness"..not sure if it's acidity (doubt it)...even the 27 sec pours lack what folks call "mouth-feel", even when they're 90% crema...If I used musical terms, I'd say the shots lack "bottom (bass notes), and have a lot of "upper mid-range", even the Malabar Gold..
The pours don't blond till around 23 secs..I stop right then...with a double basket I'm getting around 1 1/2 to 1 3/4 oz including crema
Wish i could put into more coffee specifics, but after all, I AM a home espresso newbie...

[cannonfodder]

When I was learning (and I am still learning) I was in the same boat. I finally made that breakthrough and my shot quality dramatically increased. In fact, I had one blend that was good as a cappa, but almost sick sweet as a shot. What made the difference for me was temp. I was pulling with too low a temp, but there is a narrow line between just right and too hot (which leads to a burnt bitter shot).

I cannot speak for the Ambrosia and Malabar, never used them but I need to. I do, however, have a blend that is surprisingly close to yours. It should produce a sweet shot but that much harar and guat will make for a very bright cup, very possibly what you describe as 'sharpness'. I cut the guat, replaced it with yemmen, increased the brazilian to 50% and used a good Indian instead of the Sumatra. I get much more base note and hardier mouth feel.

Try increasing your temp a couple of degrees while keeping everything else the same and see what happens. IMHO you technique and timing sound just about perfect, the only thing left is temp and brew pressure.

[IMAWriter]

Thanks....shots on Anita are consistantly show 1.1-ish boiler pressure...brew pressure is at around 9.6-9.7...when doing a backflush with blind basket, pressure is slightly higher at 9.8 or so

[cannonfodder]

You pressure is in the sweet spot, try adjusting your flush. Pull a cooling flush of the same volume, time your recovery from the end of the flush to the start of the shot, then increase that recovery time by around 5 second increments and see what happens. Trust me, when it gets to hot you will taste it. You could try tweaking your OPV down just a tad but you should be able to get good results as is, but I have not used an Anita. There could be something particular to that machine and I am sure someone will correct me if I am mistaken.

[IMAWriter]

Not sure if it's relevant, but my machine cycles about every 45 seconds...
I usually do a 6oz flush when pulling the first shot of the day...most likely a "sink" shot....2-3 minutes later I'll pull another, with a 2 oz flush, or when water dance ceases...I've previously loaded PF and basket, so I'm locked in about 6-10 seconds after the flush...I'll can try waiting a bit longer, but the boiler will sometimes recycle(red light on) during the shot...