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Advice sought: Rancilio Silvia 'gusher' extractions

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  • #16
    G'day n.t.s....

    Yep, that intruding shower-screen bolt-head will be doing you no favours for sure. Best to keep the dose below that until you have the button-head screw fitted...

    Having said that though, looking at the coffee grinds, I would say that there is still room to grind a bit finer than that. With my machine, it's currently setup to run at around 8.5-9.0Bar and my grind size would definitely be finer than yours, regardless of the basket I use. With tamping, more important than actual applied tamping force, is that you apply a nominal force consistently and as level as is practical to do (good advice about that above). It's easier to be consistent with a heavier applied force than a light one.

    From your posts above, it seems that all the baskets you are using are of the 'ridged' type. These can make the application of a consistent tamping force more difficult because of the ridge intruding into the coffee cake, and absorbing some of this force instead of the coffee being compressed. No need to worry about grabbing VST baskets or similar as any decent quality 'ridgeless' basket (Synesso for example) will make life much easier for you and well worth the small investment.

    I'd also highly recommend the hiring of Greg Pullman's 'Pressure Gauge Group Handle' as mentioned by Javaphile above. It is a simple procedure and once completed, you will know for sure that the OPV is properly adjusted and should not need touching again for a very long time. A very inexpensive and beneficial thing to do.

    Don't know that there is much more advice that can be offered to be honest, Everyone seems to have covered all the variables that affect the pouring of consistently excellent espresso. I suppose, just to be sure, you could also buy a bag of professionally roasted coffee from Andy or one of the Site Sponsors, to take the coffee out of the equation. Anyway, all the best with your troubleshooting efforts...

    Mal.

    Comment


    • #17
      Well another 2 gushers this morning. Used the LM 17g baskets put exactly 17g into each one (which based on the shower screen imprint after shows they were perhaps still a tad overdosed). Upon hitting the extraction button nothing comes out for around 6-8sec but then I get a gush which within 4-5sec I have to terminate. Both shots were quite bitter and definitely not to par.

      Tamp was as even as I've ever done, very firm (absolute nightmares to get out of the LM baskets later).

      So no great progression on thoughts from yesterday to be honest.

      @dimal, much thanks for your reply. Yes the well known Rancilio bolt - wonder if anyone from Rancilio ever confirmed why they never changed this. I just got confirmation from another CSer it was a straight swap over so I'll do this - previously there had been information implying some machining was also needed but obviously this was incorrect. Am sure thats not helping but surely a very minor part of the base issue (though have been told Silvia's prefer a good amount of headroom under the Shower Screen and if you're getting a big imprint you're overdosing too much).

      Appreciate your feedback on the grounds and I was conscious that a few of those grind sizes on that photo did look larger than expected (that said it is a post-extraction photo where obviously the grinds have expanded significantly can't be equated to a pre-extraction grind size) - if you know what I mean. So I understand where you're coming from but I suspect the photo is a bit misleading as to the actual grind size pre-extraction.

      You're correct all the baskets I currently have are ridged and I do want to get a couple of ridgeless ones if only so they assist my very amateurish workflow speed - essentially so I can preload the baskets and then bang out two extractions back to back with minimal fuss. So your point is taken but again I'd find it very doubtful that such a major issue is due to this, changing to the ridgeless strikes me as a very minor tweak that perhaps (and I've read the debates on it) improves the end cupping taste but even thats in dispute. That everything else is fie BUT the ridged baskets are throwing it all off seems an impossibility - but as stated I do want to get some when I place an order with the appropriate stores as I think they're more user friendly.

      As stated earlier after eliminating all the 'low hanging' variables the OPV is the last one there - and yes I'd have to look at either measuring the backflow or using a gauged PF to ascertain if any issues. As also mentioned to Javaphile IMHO I find the ~$30-35 total cost of the hire too high considering I can buy one from forum sponsors for ~$90 or get essentially the same gauge ready to screw on in a kit for ~$40. Thats nothing against Greg, his option is undoubtably simpler & convenient and as such it's logical a premium should be paid for it.

      I hear what you're saying however the coffee is definitely not the issue. I've no issue flagging that my tamping needed correcting however as I clarified an earlier poster my roasting is well up to par. I'd imagine it'd have to be a pretty disasterous roast if the beans were CS sourced, freshly roasted and yet so badly/incorrectly roasted that this was a significantly part of such a dire flow problem. So I know we're working to eliminate all the variables - but this isn't it. :-)

      I hope this doesn't read badly, as your post was excellent with wonderful suggestions and having worked in IT myself I know that you ALWAYS have to start at suggesting the most obvious issues first,"Are you sure the computer is plugged iin?" - so much thanks.

      Again I'm thinking it's probably the OPV/flow issue - you say yours is running at 8.5-9Bar - which by inference I would take is your recommended setting for others? Is this with a Silvia or another model?

      Much thanks again for your excellent feedback Dimal - you're by far one of the best members here and I've already received multiple excellent suggestions from you both in this and other threads so thank you.

      *** Also if anyone knows anything more concrete about how to SAFELY conduct the backflow testing on the Silvia I'm all ears - as stated earlier I'd intend to use this merely as a rough indication of what the OPV is set at and if it shows it's out avail myself to a pressure gauged PF to accurately set. ***

      Thank you in advance.

      Comment


      • #18
        Appreciate your feedback on the grounds and I was conscious that a few of those grind sizes on that photo did look larger than expected (that said it is a post-extraction photo where obviously the grinds have expanded significantly can't be equated to a pre-extraction grind size) - if you know what I mean. So I understand where you're coming from but I suspect the photo is a bit misleading as to the actual grind size pre-extraction.
        I was comparing like for like actually...

        You'd be surprised the difference a ridgeless basket makes to the whole process, especially consistency. It is worth doing and will help...

        Mal.

        Comment


        • #19
          I tried the LM baskets again (apparently they're essentially the VST design but without the finishing quality/markings) - tried down dosing to 15g on each extraction as I thought I might have gotten a marginal improvement on one I did yesterday when i did with only 14g or so.

          Again even with a firm tamp and minimal tapping etc nothing for 6-8sec and then within 5sec I've got to end extraction as volume is exceeded. The coffee wasn't bad but IMHO it also wasn't 'good' - I perhaps cut it off quick enough to avoid most of the bitterness but twas a pyrrhic victory only. :-(

          @dimal, thanks again for your feedback. :-)
          RE: grind size - I don't know I thought I was getting towards the too fine end of things, having compared to a friend's La Spaz as stated earlier. You said you felt they were still too coarse compared to yours, which machine are you running?

          Here are two pix of grinds from this mornings extractions (1 day old coffee) - first puck dug into a tad, 2nd shot using table salt to compare size - all grinds shown are POST-extraction only.




          If you think this isn't fine enough I'm happy to try this path again however my fear is that it's going to become going finer to cover up the root issue - and not that the grind size is the actual issue - BUT I'm open minded on this so if you feel its still too coarse for a stock V3 Silvia I'd welcome the feedback.


          RE: Baskets.
          As stated earlier I intend to get some ridgeless baskets but at present my focus is on the root cause of the gushing and we both know the ridged baskets are not this. Like I said earlier there's significant conjecture as to whether there's ANY extraction quality differences between the two.....but if anything there's a marginal favouritism for the ridgeless - so making this a priority is kind of like changing to an improved water softener or a higher quality tamp. Sure they might marginally assist the end result in the cup (might being the very key term) but with the colossal issue thats manifesting itself somewhere in the chain it's illogical to currently pursue. :-)

          I have seem folks theorise that ridgeless assists with channeling, but I don't think thats what I have as I don't get a trickle and then a gush. I get a straight out gush as soon as anything appears. If I were using generation 1 Rancilio baskets I'd perhaps think the basket might be more of a factor but the improved ones are meant to be pretty decent and the LM ones even better. So I'm sorry but I don't feel this is a path that the actual problems show could be alleviated by ridgeless baskets.

          That all said I'm always open to learning new things so if you're able to elaborate on what specifically based on what I've said or shown makes you feel that the basket upgrade is the most logical solution I'd be very appreciative. :-)

          Thanks again Mal, appreciate your taking the time to assist.

          Comment


          • #20
            Reading this on a phone so may be missing stuff but has anyone suggested that distribution might be an issue? Try mixing up the grounds in your PF with a skewer before levelling and tamping. I've got a mate with a Compak K3 Touch and he needs to redistribute to get good shots.

            Comment


            • #21
              Originally posted by kwantfm View Post
              Reading this on a phone so may be missing stuff but has anyone suggested that distribution might be an issue? Try mixing up the grounds in your PF with a skewer before levelling and tamping. I've got a mate with a Compak K3 Touch and he needs to redistribute to get good shots.
              Appreciate the feedback, I've tried this - didn't really assist but will try again as it's a fair call to make sure that distribution isn't the root cause and is obviously very simple to do (I'm already using the bambook skewer to level so a couple of sec more is not an issue. :-)

              Comment


              • #22
                Gday

                I have V3 Silvia since 2010(started on V2, now on V3).

                My thoughts.

                if you are using stock standard Silvia double basket then you need 17 grams for a double, maximum for this basket is 18 grams.
                Anything less than 16 grams will be poor and even 17-18 grams on stock basket will be just OK but not special.
                I suggest you replace basket. I use Synesso ridgeless double, takes 19-20 grams as optimum with 21 grams as maximum and 18 grams as minimum.
                if you use stock Silvia double basket then anything under 16 grams is under-dosing.
                If you dont have scales with accuracy of 0.1 grams (not 1.0 gram but 0.1 grams) then you must buy those ASAP, it is not negotiable item, IMO.
                Next thing - your grind looks too coarse from photo.
                First try 17 grams on the current grind on standar double basket and see how you go, perhaps up to 18 grams.
                If still too fast with firm tamp, then lower the grind and reduce to 17 grams.

                BTW - naked portafilter is very highly recommended, I use it.
                But most important item is scales with 0.1 gram accuracy and second is to get a better (bigger) double basket that takes 19-21 grams range (as weighed by your 0.1 gram super accurate scales).
                Silvia naked portafilter basket is huge, it is more like a triple basket, it needs 23-24-25 grams for a good shot and can go to 25-26 grams, but it will be STRONG brew.

                Comment


                • #23
                  Hi acid_rider,

                  Appreciate your reply just thought I'd address your points.

                  I suspect you're grinding quite a bit finer than myself to fit that much into the stock basket (#102) - it's a PITA and no rush needed but if you could post up a macro image of your grind next to table salt (as a reference) that'd be most appreciated.

                  But to get those types of doses into that filter with still the required amount of headroom I suspect you're grinding quite a bit finer and applying a very firm tamp.

                  As stated earlier getting ridgeless baskets is a goal but I'll use the LM 17g ones in the interim - which apparently are VST's minus the finishing polish etc - so definitely not the weak link in the chain for me.

                  RE: scales - I've ordered and have due very shortly the 0.1g accuracy scales. Making the best of 1g accuracy ones in the interim. So thats a good point and noted. :-) Point also taken on the naked PF - I'll consider grabbing one if/when available but will have to make do without for a while. :-)

                  I'll go back and try 17g on the stock #102, I imagine I'll have to tighten the grind a tad to get that in and have any kind of headroom at all in the basket.

                  I understand some people like the very big baskets but in a naked you're making that for a single drinker and honestly I find such a beverage a tad strong at this point in time - just a personal preference thing but with my preferred drink size around a 14-18g type double shot works best. But again I appreciate the suggestion.

                  Much thanks for your reply, if you have any pix of your grind size with a reference that'd be invaluable as because you're on a V3 we're comparing apples with apples.

                  PS. FWIW have you ever calibrated your OPV pressure or know for certain that the vendor calibrated it before you took receipt of your V3? Again just trying to ensure we're comparing capples with apples. :-)

                  Comment


                  • #24
                    Gday
                    I have Rancilio Rocky Dozer grinder, I use grind level 6 most of the time, sometimes 5 and rarely 7.
                    Rocky has total of 40 levels of grind (where 0 is finest, 40 is coarsest).
                    Perhaps it (ratio) will give you an idea where your grind should be on your grinder.
                    But given stock double basket of Silvia, the optimum amount of beans (given correct grind level) is about 17 grams, give or take 1 gram (16 min, 18 max).
                    Given your scales are only accurate to 1 gram, you can be easily 1 gram off, which is why you really need 0.1 gram scales so you can only be off by 0.1 gram on average.
                    The tamp pressure I use ranges from very light to medium (1kg-8kg range). I rarely use 10-15kg, I think its over-doing it, if you need 10-15kg to get the right pour then I think you need more beans or finer grind. This is personal taste only.

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                    • #25
                      @acid_rider, thanks for the reply. Yes well that assist a little - haha still love a pic but well better than nothing. :-)

                      The K3 is stepless but I get a very rough idea anyway. As mentioned, the scales I agree with - hence improved ones are already ordered.

                      I agree with you on tamp pressure, something that seems very often overdone & probably problematic.

                      PS. Any idea about your OPV's current bar setting or always run at whatever it came from the factory at?

                      Comment


                      • #26
                        Hi Nikko
                        my Silvia machine (V3 element, the rest is V2, bought in 2010) is unmodified. The element blew up after 5 years and was replaced by latest V3 element by repair shop.
                        The Rocky Doser grinder is also unmodified, also from 2010.

                        Here is what I do for double espresso:

                        I warm up Silvia for 20-25 min before the first cup is served, anything less than a 20 min warm up produces noticeably worse results - marine brass needs time to heat up so it holds the heat.
                        Apart from that, it is about equal #1 and #2 - bean weight/dose and correct grind level. The tamp pressure is #3 in terms of importance, its fine tuning thing once doze and grind are close to correct levels.

                        I use simple temperature trick - after warm up, I open water for a few seconds, I wait for light to come on, then I wait for light to go off, then wait 3-4 seconds (for water boiling noise to stop) and pour double shot - I extract ~50 ml for about ~30 seconds (give or take 3 seconds).
                        Anything more than 50 ml for a double shot, IMO, is over-extracting. LESS IS MORE is my motto. I dont subscribe to 60 ml in 30 sec story, double shot is too tall. If you have a triple basket (i.e. 24-26 grams) then extracting 60 ml in 30 seconds may be OK but everyone taste is different.

                        The best way to get consistent results is to get a naked portafilter which will tell you what you are doing wrong, as you can not see the pour early enough with a regular portafilter. Watching the pour will help with the next cup you will make, its like paying it forward. Highly recommended. And the stock double basket for Silvia, if you want to stay with it, really needs 17 grams of beans for best double shot quality (or 16 grams as a minimum). I weigh before I grind and make sure to scrape all grounds from grinder into the basket so none is left to spoil the next cup and to make sure that all beans you weigh end up in that basket, none left in grinder.

                        good luck

                        Comment


                        • #27
                          A small correction, I have a V3 Sylvia, bought in 2010 new, with the latest Sylvia V4 element replacing the broken V3 element in Feb 2015 (cost about $300 parts and labour).

                          I also replaced the stock "thick-head" shower-head-bolt with a much flatter top design (which still protrudes about 1-2 mm but not as badly as the stock standard Sylvia bolt does.
                          The completely flush flat-head bolt does not fit my V3 Sylvia, sadly, perhaps V4 Sylvia allows it, I do not know.
                          I think Rancilio really dropped the ball on Sylvia design as the poor double basket size and appalling shower-head bolt design point to a company which does not care about the home barista market, at least not in this price range. Even the cheaper Gaggia Classic has slightly bigger double basket (1 gram bigger) and a completely flush shower head bolt design. Don't get me wrong - Sylvia is very good for making espresso but it would not cost Rancilio much to fix the 1960s shower-head bolt design and to supply a proper commercial size double basket.

                          Comment


                          • #28
                            Well first positive development in quite a few extraction came yesterday. ~18g at a finer grind in the LM baskets, primarily focusing on an EVEN tamp - without full firmness gave me a couple of good ristretto type extractions. Somewhat oddly the first one was noticeably more bitter than the second, which happened again today.

                            Now normally I'd think this was caused by the temp being too low - but unsure as both times I'd had the machine on a full 20min+ and multiple boiler milkings during this time.

                            Anyway - am atleast in the right grind/dose ballpark for whatever the current OPV setting is (still suspect it's too high) - will play with the dose/tamp and grind a tad to get it a tiny bit better. Much thanks fo all the assistance, I genuinely do appreciate it.

                            Comment


                            • #29
                              Hi Nikko,
                              Glad you are getting great espresso shots. In general bitterness is associated with high brewing temperature (i.e burning the coffee) and acidic is often linked to low brewing temperature.

                              If the first shot is more bitter you may like to try a cooling flush before extracting your first shot, this is done by running hot water through your brewing group head.

                              Also to prevent your boiler running too hot during coffee extraction, try steaming your milk after brewing

                              So the sequence goes like flush, brew and then steam

                              Please let us know how you go

                              Comment


                              • #30
                                Yeah having read through your thread and the suggestions, I'd echo Bazooka and question your temperature. Sounds high. Especially if your pucks were super dry and not willing to be ejected from your basket (because all the moisture has boiled off?).. but I'm so new to this game I might not know very much...

                                I gave up pretty quickly on steaming milk before my shots with the Silvia, took too long to come down.

                                My $.02

                                Al

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