Espresso from new Silvia/Rocky has thin and watery mouthfeel

Beginner and pro baristas share tips and tricks.
MarkW

#1: Post by MarkW »

Hi all,

I have recently (3 weeks ago) taken delivery of a new Silvia and Rocky. I've been intensively experimenting with dose, distribution and tamping methods and have become and avid reader of postings on this site (which for the record are consistently informative). Initially I pulled terrible shots, and I mean really, truly, awful shots, but having implemented various bits of advice (WDT, Bottomless PF, Nutating tamp & temp surf being the highlights) I appear to be developing my pulls to something resembling drinkable espresso

However, having spent the past week trying to finesse my technique and (I thought) reducing the variables, I appear to be hitting a bit of a barrier. Here's what I'm doing:

1. 4-6 day old Premium Espresso beans from hasbean.co.uk (great UK site)
2. 15oz dose dialled in at 4 clicks above natural zero on Rocky
3. Temp surf Silvia
4. WDT, nutating tamp then 30lb tamp to finish (no shine)
5. Wait 60 seconds after boiler light has gone out
6. Cooling flush until all steam and hiss (?) has disappeared (about 5 seconds generally)
7. Lock and load
8. Pull

The result I am consistently getting is two 1.5oz shots with lots of initial crema which dissipates back to a smaller crema (say 2-3mm) after 10 seconds or so. Crema is also quite light, but does have some mottling/striping. Mouthfeel is "watery" and often "thin" although taste is reasonable (some brightness at the start with different elements developing as I finish). Pull time is 15-18 seconds with initial beading appearing on bottomless Pf after 2-3 seconds, cone after 7-8 seconds and done around 10 seconds after that. Even when I dial Rocky in to lowest grind setting possible, pull time does not improve very much with the same consequences.

I've watched some of the vids on here and have to say I feel like I'm producing a very different product. Certainly descriptions like "flows like warm honey" are nowhere near what I get!

My next approach is to attempt to ramp down pressure on the machine (I have the new model with adj valve) but I won't do that until I understand what pressure it is currently running at.

Any observations/critique/help welcome!

Great to be on board by the way. I sense this is going to become a bit of an obsession!

:twisted:

User avatar
jesawdy

#2: Post by jesawdy »

MarkW wrote:Pull time is 15-18 seconds with initial beading appearing on bottomless Pf after 2-3 seconds, cone after 7-8 seconds and done around 10 seconds after that. Even when I dial Rocky in to lowest grind setting possible, pull time does not improve very much with the same consequences.
If you are getting 3 ounces in 18 seconds the simple answer is to grind finer. Most people here (at least my impression of most people here) are pulling 1.25 - 2 ounces at a 15g dose. Certainly that ratio is going to improve the mouthfeel. See the Brewing ratios for espresso beverages thread for some related discussion.

I think your 5 sec "flush" is not needed, but perhaps it is (I have a PID Silvia so I can't speak to surfing it). 5 seconds unrestricted flow is probably a good bit volume wise.

I wonder if what you think is the zero point on the Rocky really isn't? Keep going finer. See, How to find the Rocky true zero point, and in particular, while you have the grinder cleaned out (and unplugged), snug up the burrs until you can't turn the lower spindle by hand (or use a socket wrench and extension). That should give you a good indication of how fine you can go.
Jeff Sawdy

JimG

#3: Post by JimG »

MarkW wrote: 1. 4-6 day old Premium Espresso beans from hasbean.co.uk (great UK site)
2. 15oz dose dialled in at 4 clicks above natural zero on Rocky
3. Temp surf Silvia
4. WDT, nutating tamp then 30lb tamp to finish (no shine)
5. Wait 60 seconds after boiler light has gone out
6. Cooling flush until all steam and hiss (?) has disappeared (about 5 seconds generally)
7. Lock and load
8. Pull
Move item no. 6 (cooling flush) to the beginning. Reduce the flush to 2 oz.

Or skip the flush altogether and instead do a 1-2 second bleed of the steam wand (no pump).

Or skip both of these steps to increase brew temp.

A 5 second flush is probably dropping your boiler water temperature too low.

Jim

User avatar
Randy G.

#4: Post by Randy G. »

A) Can we assume that you are using a proper sized tamper and not the plastic POS that came with Silvia?

B) Do this- keep pulling shots and keep adjusting Rocky finer until no coffee comes out for the first ten or fifteen seconds after the pump is turned on. Once that is accomplished, back Rocky off one click and try again. At this point you are within about one click of the proper setting. One click on Rocky is about three or four seconds difference in pull time. Basically, you are currently grinding too coarse- Grind Finer.

C) Silvias have a cool thermostat. The 100C thermostat was first used about four or five years ago in response to people complaining about the steam build up when Silvia was idling (the old one was 110C and is NLA). So the machine went from a bit too hot (which is easy to control) to a bit too cool which you can do little to fix except to upgrade to a PID.

D) Once you get that all straight, and you can get consistent pulls (ABOUT two ounces total in ABOUT 25 seconds), then you can deal with temperature control. It sounds like what you are doing is a bit backwards. Here is the Time Surfing procedure which is the way to go when you do not have a temperature readout:

From http://espressomyespresso.com/HowToTemperature.html (used here with permission):

1) Start with the indicator lamp off. Place steaming pitcher under hot water tap, open the hot water valve, and turn ON the hot water switch. Pump hot water until the heating lamp comes on (indicating that the brew thermostat has turned the heating element on).

2) The instant the light comes on do the following things as simultaneously as reasonably possible:
A) Turn OFF the hot-water switch.
B) Begin timing.
C) Close the steam valve.

3) While the timing continues, grind, dose, tamp, lock and load. Position your glass under the PF, ready for the shot. Depending on the next step's timing, you may need to have the coffee already ground in the doser, ready to dose, if time becomes a factor.

4) Have your finger on the brew switch and when your timing shows your predetermined time has elapsed, begin the pull by turning on the Brew switch.

But how do you know how long to wait before brewing? That takes a bit of experimentation. Without an accurate way to measure temperature somewhere in the system it is difficult to say. Try about 20 seconds to begin with. The above procedure is designed to give you the same starting temperature for every pull. This helps you develop consistency. You should get to the point where all the shots taste pretty similar. Once that is achieved you can start playing with different wait-times to adjust the taste.

The more advanced method is to get a digital thermometer and mount a thermocouple to the top of the boiler. You can monitor the temperature and do a temperature surf. That is the same as the above Time Surfing method but you flush the boiler until a predetermined temperature is displayed instead of just waiting for an amount of time to pass while flushing.

As mentioned above, the best solution is a PID. It replaces the brew thermostat (which is a cheap, archaic technology) and gives you the ability to choose boiler temperatures, but it also gives stability at that temperature.
Espresso! My Espresso! - http://www.EspressoMyEspresso.com
LMWDP #644

User avatar
lsf

#5: Post by lsf »

Just my 2 cents... did you mean 15gr? In your initial post you wrote 15 oz. and that's not the same.

Furthermore, don't be afraid to dial down rocky. I used to grind 4 clicks above the real zero to when I was using it with my Andreja. At first I thought I was grinding too fine but what mattered was the result in the cup which was great.

Keep trying and don't give up! Your efforts will be rewarded. :)

User avatar
DC

#6: Post by DC »

I've often thought about dialling the pressure down but in the end the problem was always with me, not the machine :)

I find the premium espresso blend fairly easy to get right, you could try updosing it slightly: fill the basket, WDT, then level with a flat edge and do a single straight-down tamp of around 20-30lbs (I normally work with 14-15g but some coffees work better with a little updosing).

I recently followed Mark Prince's guide to temp surfing the new Silvia on his video on coffeegeek and it was a revelation after trying dozens of different temp surfs. Try this:

Bleed just enough water for the boiler to turn on

Wait for the light to go out

Immediately bleed just enough water for the hissing to stop (2 to 3 seconds)

Immediately pull your shot.

It really works a treat. Jim Schulman also recommended elsewhere on this site that with the new Silvia you should pull the shot pretty much as soon as the light goes out (sorry can't remember the thread right now).
Dave

User avatar
Psyd

#7: Post by Psyd »

Randy G. wrote: C) Silvias have a cool thermostat. The 100C thermostat was first used about four or five years ago in response to people complaining about the steam build up when Silvia was idling (the old one was 110C and is NLA).


From http://espressomyespresso.com/HowToTemperature.html (used here with permission):
I know that you are correct, but the source you cited also says, "Contemporary Silvias (since mid to late 2001 and newer) with the 110c. thermostat ..." Is there someplace that a Silvia owner could go and discover just when each upgrade was made, and preferably by serial number or something, just what parts are in his Silvia? Mine was supposed to have been made with the 110C thermostat so I ordered the 100C, but the two seem to be the exact same thing.
FWIW, some with the new Silvia have reported good results with starting the shot as the light goes out. Anecdotal evidence and hearsay at this point, but it's worth a shot.
Espresso Sniper
One Shot, One Kill

LMWDP #175

User avatar
another_jim
Team HB

#8: Post by another_jim »

I defer to Randy on things Silvia. However, here are my impressions of the newest models with the adjustable OPV and the 100C thermostat.

-- The factory 10.5 to 11 bar setting on the OPV is quite good, and there's not much point playing with it.
-- If the 100C tstat actually clicks off at 100C, you would be good on temperature. However, one of the two I got clicks off at 95C, and it would be hopeless (I've set my PID at 100.5C to get start at 93.5C, end at 91.5 shots). Start by pulling shots the moment the heater goes off.
-- the 220V silvias have a 1200 Watt element -- on no account pull shots with the heater on, you'll be steaming the coffee by the end of the shot. If the espresso is too sour, and the crema color on the cup too light, indicating too low temps, turn on the steam switch for a few seconds after the heater light clicks off, then turn it off and make the shot.
-- You only need to flush enough to heat the PF, not at all with a bottomless.
-- If there's a shower screen impression on the puck, the shot's taste will be flat; use a deeper basket if you want larger doses.
-- A good shot has around 4 to 6 seconds of dwell time (before the first drop into the cup), then 22 to 27 seconds of run time, before it blonds.
-- When I tested the Rocky, it made superb shots one click above zero at a low dose, and awful shots 4 clicks above zero at a medium to high dose. Don't ask me why, I'm mystified; just try it and see if it helps you.

As always for heavier machines, all this advice applies after a 3/4 hour minimum warm up time. Anything less and the shots suck no matter how brilliantly you make them.
Jim Schulman

MarkW

#9: Post by MarkW »

Guys,

Thanks for all the info. I'm going to leave the mechancials alone and concentrate on technique, including some of the wise words posted above.

That said it appears that the overwhelming view is to fit a PID for temp stability. I'm not averse to doing this but am wondering a) are they expensive and b) are they easy to fit? I am an accountant with absolutely no electrical experience whatsoever and there is a better than average chance I will muller the machine if I even attempt to fit something complex. Can anyone recommend a good UK PID supplier or a US one who will ship?

User avatar
HB
Admin

#10: Post by HB »

MarkW wrote:That said it appears that the overwhelming view is to fit a PID for temp stability. I'm not averse to doing this but am wondering a) are they expensive and b) are they easy to fit?
Not sure what you mean by "temperature stability" above.

In a nutshell, a PID in this context is a fancy electronic thermostat; it controls the brew temperature to a fraction of a degree, unlike the stock mechanical thermostat's wide deadband (delta between heating element on and off). A PID eliminates the tedium of the well documented steps of temperature surfing, but doesn't change the fundamental shape of the intrashot temperature profile. In other words, adding a PID may reduce sink shots related to brew temperature mishaps, but doesn't change Silvia's "exceptional espresso" potential.

The HB forums have quite a few discussions of Silvia PIDs, as does CoffeeGeek and alt.coffee. Below is just a sample: Googling PID Silvia will lead you to purveyors of prefabricated kits and DIY instructions. The prefabricated kits are more expensive, but they save you the time of figuring out the details. Jeff recently documented the steps for converting a Quickmill Alexia (link); the steps for Silvia would be similar.
Dan Kehn