Rancilio Silvia with PID vs. competition on shot quality - Page 2

Need help with equipment usage or want to share your latest discovery?
Frost
Posts: 136
Joined: 16 years ago

#11: Post by Frost »

Jim, were you able to draw any theory(s) as to what makes the Silvia shots run this way? With your experience on various machines E61, otherwise, manual lever, etc. I'm curious if you have any ideas on the nature of the problems. From the muddy, indistinct description it does not sound at all temperature related. More likely to be details in the extraction, pattern/pressure ramp/preinfusion? I have no experience with Silvia but always interested in de-mystifying and better understanding the espresso extraction process. Thanks for any clues.... or hunches even if unfounded or untested. :)

User avatar
another_jim
Team HB
Posts: 13872
Joined: 19 years ago

#12: Post by another_jim »

Preinfusion makes machines more forgiving; but the taste of well drawn shots is unchanged, at least on machines with adjustable preinfusion times.

Elektra machines perform better than expected, and Silvias worse, if one bases expectations on repeatable and precise temperature and pressure profiles. My guess is that this has something to do with the water path and water quantity.

The Elektra's brew path is straight down, and the dispersion is incredibly over-engineered and even. The space above the puck is tiny, so the amount of water involved in the brewing process is minimized (i.e. a higher proportion ends in the cup and a smaller one in the drip tray). This is reminscent of lever machines, where very little water is wasted (it is drawn into the piston, then pushed into the puck and cup), and the path is straight down. Lever machines are not crema champions, but they are known for taste clarity, despite their crappy temperature control.

The Silvia's brew path is basically horizontal, and the dispersion block is a joke. The entire twelve ounces of water in the boiler is implicated in the brew process, and the amount in the drip tray is fairly hefty.

I have neither proof nor ideas on how to prove if these are the key differences, but they are the prime suspects.
Jim Schulman

Alan Frew
Posts: 659
Joined: 16 years ago

#13: Post by Alan Frew »

another_jim wrote:I think the Silvia, with or without PID, with or without OPV, makes distinctly inferior tasting shots to any E61 or other commercial machine with a decent group.

My evidence: I had a pair of Silvias set up identically to do grinder and coffee blend tests, these were both PIDed and with the new OPVs set to identical blind filter pressure. I thought this was a stroke of genius. The low 800 watt draw of the machines made pairing them an attractive way of getting an inexpensive home two group test machine; while having one start up in the morning on steam, and one on coffee, took care of my morning cappa. But the outcome was disappointing. Shots from different grinders or blends were invariably far less distinct from the Silvia than from any other machine I tried. In terms of taste, the Silvia's shots were incurably and terminally muddy. So like most of my other genius ideas, this one ended up on Ebay.

Don't get me wrong. I would always prefer a Silvia to a Gaggia Classic or any other small home machine, the others aren't even close. But it simply isn't competitive in shot clarity with inexpensive HX machines like the Expobar, Bezzera BZ, Oscar, or any of the E61 single boiler machines.

Therefore, I do not think the Silvia is a good choice for someone who is a serious home roaster or someone who is spending a lot of money on the high end espresso blends or SOs. The Silvia cannot adequately render their taste.
Wouldn't disagree, except with the phrase "inexpensive HX". It's all relative, and shipping, currency conversions and tax regimes can multiply relative differences even further, but in my world the cheapest HX is more than double the price of the Silvia. This is true even if you go to ex-factory pricing, a Silvia costs about 300 Euro and the cheapest HX is about 600 Euro. Try convincing the average espresso neophyte that they need to double their budget and triple their electricity bill before they start!

Alan

weasel (original poster)
Posts: 58
Joined: 15 years ago

#14: Post by weasel (original poster) »

Thanks again everyone. Lot's of great information. Thanks Jim (Schulman) for so succinctly putting the Silvia into perspective with regard to her shots:
another_jim wrote:Don't get me wrong. I would always prefer a Silvia to a Gaggia Classic or any other small home machine, the others aren't even close. But it simply isn't competitive in shot clarity with inexpensive HX machines like the Expobar, Bezzera BZ, Oscar, or any of the E61 single boiler machines.

Therefore, I do not think the Silvia is a good choice for someone who is a serious home roaster or someone who is spending a lot of money on the high end espresso blends or SOs. The Silvia cannot adequately render their taste.
I bet many prospective buyers would find those words useful.

weasel (original poster)
Posts: 58
Joined: 15 years ago

#15: Post by weasel (original poster) »

Just thought I would update this post.

Before Christmas I saw the screamin deal offer by 1st-line on the Silvia. For me it was too good to pass up. My budget is at the low end, and judging by the comments, here and elsewhere, I felt I would be happier with Silvia than a Gaggia. It didn't hurt that 1st-line had a deal on the Lelit grinder as well, two for two! I didn't expect to get an espresso set up this year, or even next. When my cousins offered to chip in on my 'present', DEAL!

Hopefully none of the contributors to this thread will think that their words or advice were in vain. All comments were considered and appreciated. I would have loved a cheap HX, but all things considered, my budget (and average palate) won the argument.

For now, I'll suffer through the temp surf, and probably add PID next year. I expect the machine, grinder, et al, to arrive within a few days, nothing to report just yet. I'm sure I'll be far more satisfied with the resulting espressos/macchiatos than I was with the borrowed FF/Infinity set up.

3lbs of Klatch ordered, I should be hoppin by New Years!

Endo
Posts: 337
Joined: 16 years ago

#16: Post by Endo »

Congratulations. You made the right choice.

The Silvia is a great machine on all accounts. The Le'Lit is a good match as well. You'll enjoy great drinks and be able to develop your Barista skills for as long as you like. Should the upgrade bug bite, you can always add a PID and if you are severely bitten (like me), the Silvia has amazing resale value.
"Disclaimer: All troll-like comments are my way of discussing"

User avatar
AndyS
Posts: 1053
Joined: 19 years ago

#17: Post by AndyS »

another_jim wrote:Elektra machines perform better than expected, and Silvias worse, if one bases expectations on repeatable and precise temperature and pressure profiles. My guess is that this has something to do with the water path and water quantity.

The Elektra's brew path is straight down, and the dispersion is incredibly over-engineered and even. The space above the puck is tiny, so the amount of water involved in the brewing process is minimized (i.e. a higher proportion ends in the cup and a smaller one in the drip tray). This is reminscent of lever machines, where very little water is wasted (it is drawn into the piston, then pushed into the puck and cup), and the path is straight down. Lever machines are not crema champions, but they are known for taste clarity, despite their crappy temperature control.

The Silvia's brew path is basically horizontal, and the dispersion block is a joke. The entire twelve ounces of water in the boiler is implicated in the brew process, and the amount in the drip tray is fairly hefty.
This is very interesting, because it suggests that design features we normally do not consider may be significant for the best espresso.

I don't think Silvia's dispersion setup is as bad as you say, though. With flow restriction (ie, retrofitted gicleur), her shower screen can deliver an even, gentle rain. It is easily as soft and as uniform as that issuing from the new Speedster. (Please note, I'm talking about a modified Silvia flow rate but with the stock dispersion block and screen).

I also don't understand what you mean by "the entire twelve ounces of water in the boiler is implicated in the brew process." My flowmeter measures about 42 ml water used for a typical Silvia double shot. It works out like this:

Inputs:
42 g water
14 g dry coffee
56 g total

Outputs:
18 g espresso
27 g spent puck
45 g total

Due to conservation of matter in Newtonian physics :-) the input must match the output. 56g-45g=9g, which must be the amount of water lost into the drip tray. Is that so bad, 9g lost out of 42g? I plead ignorance, but the 42g of water used to brew a double shot is less than 1.5 oz, a small fraction of the boiler capacity.

I believe Dan has stated that the Elektra machines ramp up to pressure (and therefore, flow) very quickly. Perhaps this is the design decision that necessitates an "overengineered" dispersion system, in order not to disturb the puck.

Is a quick pressure rampup better at delivering flavors, IF one can maintain the puck's integrity? I do not know.

One thing that has always bothered me about my Silvia is the slow temperature rampup. It takes ~12 seconds to come up to temperature. That's more or less half the shot. This temperature rampup parameter is something that's generally been ignored in all the hoopla about temperature stability. Schomer, the King of Temperature Stability, pretty much ignores the first few seconds. And IIRC, the WBC folks made a decision to ignore the first seconds because they claim their measuring instrument isn't fast enough.

But as you know, Mr. Teahan suggests an unusually hot first few seconds may be useful in bringing the puck up to brew temperature.

I'm just blabbering on here, but is it possible that some of the shortcomings you find in Silvia are due to her temperature profile, not the brew water path?
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company

User avatar
another_jim
Team HB
Posts: 13872
Joined: 19 years ago

#18: Post by another_jim »

Hi Andy,

I don't know why the my test Silvia's tasted muddy. They had OPVs and PIDs, the profile was the typical Sivia straight declining line, which is purportedly quite good. The body was lovely, as was the crema; but the taste was like listening to music on a cheap car stereo -- indistinct.

I'm hypothesizing the water path. However, given my current state of ignorance, it would probably be more accurate to state that the problem is in the brewing geometry, which is characterized by variables to be named later. I could be wrong, but I don't think there's a lot of gold left in temperature hills.

BTW, are your water readings are good for a stock Silvia? My purely eyeball feel is that the Silvias flushed a lot of water at the end of the shot.
Jim Schulman

User avatar
AndyS
Posts: 1053
Joined: 19 years ago

#19: Post by AndyS »

another_jim wrote:Hi Andy
...are your water readings are good for a stock Silvia? My purely eyeball feel is that the Silvias flushed a lot of water at the end of the shot.
Hi Jim:

With some regularity, people ask me questions about stock Silvias. I'm supposed to be a Silvia guru, somehow! :)

It would be interesting to me to play with a stock Silvia sometime, but I really don't remember much about how they are. It's been 8 years since I started irreparably modifying my Silvia!
-AndyS
VST refractometer/filter basket beta tester, no financial interest in the company

Post Reply