First, I'd like to thank Jim for his useful and informative reply to my post under the Basket Overdosing thread, and his positive and encouraging tone. He's the only one who actually tried to answer the questions I asked instead of warning me that Silvia will doom me to failure, suggesting I'm a half-assed newbie who won't get consistent drinkable shots for months, or holding forth on the best way to approach complex systems with interdependent variables. Jim gave me sound recommendations on buying a bottomless PF, 1/10 gram scale and a different basket (all of which I'd already done) and gave me a great suggestion for where I might get good SO coffee suitable for 14g shots. The only remaining question that still hasn't been answered is whether anyone has successfully pulled 14g shots on a Silvia. It might save me some time to know that.
Most of the other replies contain a lot of chest pounding and irrelevant theorizing. In the course of arguing with each other, I think some of you are missing the point.
The Golden Rule says (approximately) 14g, 60ml, 25-30 sec. Strong arguments have been advanced that Italian espresso machines are designed for 14g doses. That's what they use in Italy, without all the fancy dancing and tamping done here in the U.S. to get an updose to pour correctly. If this was all I knew, then I would undoubtedly begin by setting one of the variables, the dose, to 14g.
But I've learned that popular espresso blends are designed for updosing, and there are posts claiming Silvia does better at higher doses (perhaps this is due to the factory brew pressure setting being too high?) Further, of the dozens of Silvia shot videos I've watched, I'd be willing to bet not a single one used a 14g dose. The typical technique is to overfill the basket, tap, fill again, level with a personal favorite method, tamp, tap the side (maybe), tamp with anywhere from light to heavy pressure, polish, shake out loose grinds (maybe), do a little dance, bend over, kiss one's ass, pray for a god shot, etc. I have no doubt not a one of those baskets contained less than 16g of coffee, and most of them were probably in the 18g-21g range.
So what's a newbie to do?
Well, I thought I'd try it both ways. My plan was similar to what Jim suggested with his five key variables. Having not yet identified a coffee suitable for 14g doses, and because of the possibility that Silvia's factory pressure setting may be somewhat high for that dose, I thought it would be best to start with an updosing technique like what I saw in the vids, try to dial in the grind for volume and time, and work on the distribution to get a decent pour -- all the time tasting to judge the effects of each change. It shouldn't be too hard to rig a thermocouple (which I have) to check the temp at the bottom of the puck and adjust the PID accordingly (and I may need to experiment with flushing the group just before a shot to heat it up if the machine's been idle.)
Yeah, I realize only one thing should be changed at a time (where possible), and also realize it will probably take a lot of time and many sink shots to get anywhere close to an acceptable result. I also realize I might get sprayed with coffee, might get frustrated, and might have some very disappointing sessions. I'm prepared for all that.
Ideally, I would move to the 14g dose after getting a decent and consistent updosed shot and identifying the right coffee for 14g. I hope it happens that way, but I understand that Silvia's idiosyncrasies may complicate the effort. I may not be able to get a consistent or even decent updosed shot if Silvia's brew pressure isn't right. I might have to adjust the OPV for less pressure. I don't know yet. Yes, I was expecting I might need a pressure gauge at some point, but there are some accuracy questions associated with using one and I'm not ready to delve into them yet.
It seems to me that it's just as valid to try a 14g dose *before* trying more involved operations like measuring/adjusting pressure. What if my 14g doses taste better than 18g doses without making any machine measurements or adjustments at all? I'm not saying it's likely, but it's certainly easier to try than fooling with the pressure, especially if I'm not sure about the accuracy of the gauge. Having learned that the popular blends aren't suitable for the 14g experiment, my main concern was getting the right coffee. That's why I asked about it.
My point is that dose is one of the variables I can try to change on the road to producing consistent good shots. I don't see why I necessarily have to make the machine produce a consistently good updosed shot before I try that, especially if it proves difficult to do so. The worst that can happen is that it won't work, and I'll have to turn my attention to other variables.
Heck, once I find the right coffee, there's no reason why I can't start with 14g doses, dial them in as best I can, and compare with updosing one of the popular blends.
I appreciate the advice on changing one variable at a time, but it sort of put me off.
By way of introduction: Although I'm new to espresso, this is not my first rodeo. I have a fair amount of experience with systems that have interdependent variables. I'm also a veteran of some expensive and complex hobbies like high-end audio, wine, and amateur radio, all of which take a lot of patience to learn, feature many interdependent variables and have results that can be evaluated via scientific measurements or subjective sensory judgment. I'm highly technical and enjoy solving difficult problems. I'm also off-the-charts intuitive (for Myers-Briggs fans), which hopefully adds some art and creativity to my endeavors.
These are some of the reasons I selected Silvia. I'm intrigued by the challenge and the learning experience. I like working with test equipment and there's a decent chance I'll make further mods to my Silvia (I'm the sort who doesn't hesitate to open a multi-thousand dollar piece of gear, even while still under warranty, to fix it or make it better.) I read in one of the "dump on Silvia" threads that what is learned by trying to make Silvia produce good shots is useless information that can't be transferred to other, more forgiving equipment. Perhaps, but I suspect that's not entirely true. I think I'll learn a few things and have a lot of fun. Heck, if I get too frustrated I'll just sell the thing and buy a machine with an E61 group head! No big deal.
Why not do that now instead of buying Silvia? Can I afford a better machine? Yes. Can I afford to skip all the rigmarole and go straight to a multi-thousand-dollar, top-of-the-line machine that will pull great shots with little effort on my part? Perhaps. I might end up doing that. Do I want to start that way? No. There's a difference between being able to afford and being ready to make a major commitment.
First, I want to thoroughly understand the interplay of all the many variables that go into producing a good shot. I want to learn how to make a good shot without the help of an E61 group head. I want to thoroughly understand how Silvia works. I want to figure out if it's worth investing in simultaneous frothing capability to make milk drinks for my wife, my daughter or company (right now, I don't even know if they'll want them.) I want to gauge just how much my palate can detect. I want to determine how important it is to me to squeeze every flavor note out of the coffee versus just getting a decent beverage in the morning (I've been drinking tea for the past five years, folks.) And yeah, I know Silvia muddies the shot, but I also know it can produce a tasty shot nonetheless. I want to know if espresso is critically important to me, or just a passing fancy (if the former, then I'm likely to skip the intermediate machines and go for the best.) Silvia seemed like the minimum and perfect entry level machine to determine these things and learn about making espresso, plus she has excellent resale value if I decide to upgrade. There is a vast body of work on tweaking and modifying the machine. You may not think the aggravation is worth it, but you are not me.
I guess this means it's not 100% about drinking a great cup of espresso whenever I want. Yes, that's a huge part of it. But for me, it's also very much about the process of getting there.
Sorry for the semi-rant. I have nothing better to do while I wait for Silvia... (Every time I hear that name I can't help but think of Albee's "The Goat, or Who is Silvia?", in which the hero falls in love with a goat named Silvia. It's quite shocking news to his wife.)