Hi all. It's been about 2 weeks with my new stock silvia. Using a stock rocky grinder and freshly roasted espresso blend (allowed to degass) from Coffee Lab Roasters in Tarrytown, NY. I have ordered some black cat for a better baseline to eliminate some variables.

Here's my problem. I am consistently getting either sour and fast extractions or slow and bitter ones. I am using the stock ridged silvia double basket in a 1-st line bottomless portafilter. I overfill the basket, level with finger and tamp. Sometimes it seems as though the ridge in the basket is interfering with tamping. Fast extractions are running around 20 secs and slow extractions are running around 30 seconds (for the pour to 2 ounces or as soon as I think it's blonding). This is usually happens between only 2 adjacent settings on the rocky grinder. Am I hitting the limitations of my grinder?

Any advice on other variables I should be careful with? It's very frustrating, if I go by pour time and crema indication (28-30 sec shot with good looking crema, right volume, etc) it seems to still taste too bitter. Is it true that espresso will not be bitter at all if made correctly? I have yet to visit a cafe where it is not, although my shots at home are not measuring up to near a cafe standards.

Also, can someone recommend a shop with a good example of an excellent espresso in the Southern Connecticut Area?

The ridged basket I received with my Silvia was also too small for my 58mm tamper.
After convincing the guy at the store, he gave me a new basket (same model number). The new basket fits like a glove. Looks like Rancilio has some issues with the production of these things. I've heard more people complain about this.

Also, I just adjusted my OPV 1/2 CCW and it has made an enormous difference in taste. Good bye bitter espresso!

Sean, can you get any repeatability at all?
I bought a 'ridgeless' years ago that the tamper would bottom out on. The stock Rancilio double basket isn't bad.
Try to remove some of the variables:
1. Revert back to stock double basket. See if you can get any repeatability in shots. 3 sour shots in a row, roughly same extraction time, or 3 bitter shots in a row. We're trying to take variables out of the equation.
2. Is your dosing routine the same each time? Tapping the portafilter can effect the density of grounds in the basket, and can add a surprising amount of time to the extraction. Try dosing with no manipulation of the grounds until you have a full basket. One key is how high the tamper is sitting after you tamp. It should be the same height each time.
3. If the tamper is bottoming out, you'll need to replace it. If you can afford it, I like the Reg Barber 58. There's quite a few good ones, and this thread http://www.home-barista.com/knockbox/hb-roadshow-espresso-tamper-reviews-t1912.html shows the measurements of various models.
4. Tamping pressure - are you confident your tamping has approx the same pressure each time. Make sure that you're straight up and down, and the same pressure. Take a look at the tamper after and see if it's straight.

Run through the steps. If you're able to establish some consistency, even if it's bad, it's a place to start dialing things into the sweet spot.

Also, remember that the stock Rancilio, even with fastidious attention to temperature surfing is still going to deliver somewhat inconsistent results. But work on getting consistent extraction times, and then you refine the other parts of your approach.

I agree, adjust the pressure down. The new OPV silvia's come set at 11, adjust it down to ~9 and your whole world will change. Then start your learning process over. This, other than PID, was the single most important thing I have done.

Since your Rocky grinder has relatively coarse adjustment steps, you can try adjusting your dose to tweak the pour time and volume. Do beware of hitting the shower screen with your dose, though.

In my experience, volume dosing Silvia does not work very well. It has been awhile since I have used her but I found weighing each shot gives the best results. (yes, even after you install the PID )

I am using the stock silvia basket and I believe the ridge is preventing a full tamp and causing uneven tamping and forcing me to updose. I think I'll have to order a ridgeless basket as tampers are more expensive hehe. Any suggestions?

I received the black cat and I'm having an even harder time with it. I get either chokes or sour shots even when volume and time are correct and it appears to be overextracted. I temperature surf the same way every time and do let off the initial steam flash before pulling the shot so I don't think low temperature is an issue for the sourness. Maybe the beans are too new, roasted on the 21rst and today is the 23rd. Do beans taste sour? I know they will be blond but mine have not and are unbearably sour. I'll stop the black cat and wait for the recommended 7 days.

It's generally understood that silvias ship with the pressure slightly too high right? Not sure if I want to touch the adjustment on the OPV until I get consistent results.

are you sure your machine is hot enough when you pour your shots?

Good point. The boiler gets up to temp in 7-8 mintues, but the grouphead doesn't get saturated for around 50 minutes. Make sure you're fully warmed up.