Temperature surfing Rancilio Silvia

Need help with equipment usage or want to share your latest discovery?
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gardoni
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#1: Post by gardoni »

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By the way Dan,

I forgot to ask you a question. I usually pull one shot and then froth milk for a latte. But before I do anything I pull a blank shot with the PF still on in order to warm it up. I then let some water go out from the steam wand(without turning the Steam button on) and then grind and tamp. Before I pull the actual shot I do a cooling flush until I see that the water coming out from the group isn't boiling hot and then I immediately lock in my PF and pull the shot. Do you think this is a good routine. The reason I ask is because I came about a topic called DEAD Silvia on another forum and it talks about "cooling " the group etc. Here's an excerpt:
Hi Folks--that red button fix on the dead Silvia worked! Thanks Dan!!! You really saved me some serious consumer anxiety. And you answered so quickly. What a guy! But I have FURTHER QUESTIONS! I did not leave it on. I did make about 10 practice lattes--I did refill--I did "cool" the group to brew, etc. I had the machine on about 3, maybe 3 and a half hours. Max, 4 hours, but I really think less.
Is there a general rule, how long Silvia should be left on? On steaming, cooling, etc--how to not burn her button? Thanks very much! Coffeegeek is amazingly helpful.
I would really appreciate it if you could give me your opinion and help me establish a better routine.

Thank You,
Gardoni

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HB
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#2: Post by HB »

gardoni wrote:Before I pull the actual shot I do a cooling flush until I see that the water coming out from the group isn't boiling hot and then I immediately lock in my PF and pull the shot. Do you think this is a good routine.
I summed up my Silvia temperature surfing routine in Some extraordinary results by reverse temperature surfing (excerpted below). Others chimed in to offer their approaches that weren't as time consuming. I would not expect your "flush and go" routine to yield consistent results and recommend one of the slower surf and wait routines. Reducing this tedium is one of the reasons PIDs are so popular with Silvia (and why it's a frequent upgrade victim).
dan_kehn wrote:My coffee buddy, Richard, bought my Silvia/Rocky setup. For the last few weeks he's been complaining about sub-standard shots, describing them as bitter / harsh. My answer was always the same: "Your temperature is off." He tried temperature surfing but still complained of good shots one day, terrible the next, and no great shots at all. Yesterday we got together for the Rocky/Mazzer shootout rematch (click here for the first match results by CraigA). Afterward, we turned to diagnosing Silvia. Another CoffeeGeek, David Morris, mentioned the idea of temperature surfing after reaching max temperature. I wanted to investigate this idea of "reverse temperature surfing."

We did a lot of temperature trials to reverse temperature surf Silvia accurately. Normally when you temperature surf, you introduce water into the boiler, wait for the heating element to come on, then wait n seconds for the water to heat up to your target temperature. Problem is, my measurements showed variance, probably because split-second response can make a big difference (e.g., two seconds too much water and you're off by several degrees), not to mention "warm versus very hot" Silvia variations. I also noted that his machine put out a lot of water, almost 10oz in 30 seconds. Again, that makes it hard to temperature surf accurately by introducing water.

So instead, we tried the other direction, hence why we call it "reverse temperature surfing." We introduced water until the boiler came on. Then we waited for the heating element to turn off. Then we plotted the drop off in temperature (1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes... really boring stuff). By trial and error, we found that 2 minutes after the boiler clicks off with a well heated Silvia, the temperature reached 201F. At first we would get variances of 196, 197, 199, 199... and then 201, 201, ..., 201. It was that dead-on, time after time after time. His wife is a statistician and says we'd have to take at least 25 measurements to have any true statistical certainty; we stopped after six consecutive results of 201F. Obviously this type of temperature surfing requires lots of patience, since you're waiting about three minutes to get to the right temperature by the time it heats up to boiler shutoff and cools down to your target temperature.

To make an already long story short(er), this technique seemed to produce pinpoint accurate temperatures. Since the boiler is cooling (not heating as would be the case in 'normal' temperature surfing), we suspect the temperature stability during the shot is enhanced. The Intelligentsia Black Cat shots we pulled yesterday afternoon using this technique were some of the best Silvia has ever produced. Two shots from the Silvia/Mazzer Mini trial were "rock your world" calibre and we rated the third "very good to excellent".
Dan Kehn

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gardoni (original poster)
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#3: Post by gardoni (original poster) »

dear Dan,

Thank you for your advice. I will look into temperature surfing.

Sincerely,
Gardoni

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erics
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#4: Post by erics »

And the only thing I could add to the excellent advice you have already received is:

After you do any steaming with Silvia you need to run about 4-5 ounces through the grouphead to cool it down. While a lesser flow may very well take the water in the boiler into the brew thermostat's range, the grouphead will still be overtemp.

And after you feel you have had enough with temperature surfing, you can look into one of the fine PID kits available here:

http://www.mlgp-llc.com/PID/index.php

Eric S.

stofer
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#5: Post by stofer »

I use the reverse temp surf on my Silvia, it works very well, but there is obviously a difference between my machine and the one this technique was "developed" on 'cause I pull shots about a minute after the heater goes off, 50 sec for high temp blends, 60 for low temp.
I recall hearing something somewhere about different brew temp thermostats on different batches of Silvias, this would explain things.
So if you try the technique described here and get sour shots, maybe you have the same lower temp 'stat that I have, in which case you should try pulling about a minute after the light goes out.

robin
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#6: Post by robin »

I've heard a lot of good things about the new thermostat, has anyone experimented on the new Silvia? Is it still as finicky, and to what extent i temperature surfing necessary?

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erics
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#7: Post by erics »

Silvia's brew thermostat was changed from 110 C to 100 C about 4-1/2 years ago. I believe this is the NOMINAL temperature at which the thermostat opens the heating element circuit but it may be the NOMINAL midpoint instead. The wattage of the heating element for Silvia's destined for the NA market is, I believe, unchanged at 800 watts. European, Australian, New Zealand wattage is 1100.

Eric S.

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gardoni (original poster)
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#8: Post by gardoni (original poster) »

Hello,

I just wanted to thank you all for the wonderful advice.

Thank you Erics, Stofer and Robin. Oh, and Dan too.

Sincerely,
Gardoni