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Help diagnose shots - Linea Mini

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  • Help diagnose shots - Linea Mini

    Hey all,

    I have a Linea Mini with Rick's preinfusion kit, playing around with lots of different styles, but seem to be getting pretty ugly shots from the bottom of the portafilter most of the time (I know, taste in the cup etc etc etc), but still feel like I'm missing something from the final result.

    Most of the shots never end up looking 'full' - i.e. they start evenly, but then up looking like they're never converging into a single stream, I've tried grinding coarser, finer, different beans, etc, and it doesn't seem to change much apart from if I go too coarse it starts to look like a river...

    Shot 1 - light roast:


    Shot 2 - light roast (you can see what I mean about the shot not looking 'full' quite clearly here:


    Shot 3 - dark roast (too fine):


    Shot 4 - dark roast:


    Any theories, or am I overanalysing everything?

    Scott

  • #2
    Do you use wdt?
    How do you level and/or tamp?

    Comment


    • #3
      Agreed, this looks like a puck prep issue.
      Hit us with some workflow details.

      Comment


      • #4
        Lagom P64 grinder, I use WDT or an SAI Shot Collar, SAI Palm Tamper or Pullman Bigstep Palm for tamping.

        Light roast: 18g VST basket, 18g in
        Dark roast: 22-25g Pullman basket 22.8g in.

        Comment


        • SanderP
          SanderP commented
          Editing a comment
          Looks like a puck prep issue.

          Go back to basics and keep it simple.

          Change one variable at a time.

          Sometimes less is best, ironically this can be especially true when it comes to gadgets designed to solve puck prep problems!

          Cheers

      • #5
        Well then the only thing I can think of is your shot collar depth may be a tad low, have you tried adjusting that?

        Comment


        • #6
          Scotty first off relax.....there's nothing wrong with 2spouts or 3 from a naked.....its just not where you want it to be.
          And yes the flow rate is a touch too slow. And yes I would expect the beans to give up to a faster flow rate later in the pour.
          But from what Ive seen your beans are holding up throughout.

          There was a thread 2-3 years ago with exactly this issue. A guy had a new mobile van, the thread went on and on for months.
          Search for - 'Donut Pour' Naked Basket etc.

          I can get the same effect at times and open up the next shot slightly. = Faster flow rate.
          Can be grind, Or lighter tamp depending on your puck setup.

          Id suggest you be certain about your dose. Are you aware VST stated that their basket(s) were designed with a spec of between 1.5mm to 2.0mm head height?
          5c = 1.35mm, 10c = 1.75mm

          Shots 3 and 4 the spouts are flowing central and even, they are simply maybe less than 1/2gr per sec flow rate away from giving a single spout type flow.
          Shot 4 is showing good Crema.

          Given what you've posted to date persevere with adjusting grind coarser bit by bit.
          As Sanders says above and I'm sure you'd agree, only change one thing at a time.
          GL with it.
          Pls post back your findings.

          Comment


          • #7
            Yeah you’re right they’re not great are they. I’m usually a real advocate for investigating everything else before blaming equipment, but in this case I have to ask - what’s the current state of the grinder? Is it new? Is it clean? Have you had it apart at all? I’ve heard the P64 needs some ‘running in’ to get the best out of the burrs so maybe it’s just a symptom of a new grinder. But if we go back and assume that there’s no equipment issues and the coffee is fresh then I’d say that: - Shot 1 is ground too course and dosed too high. - Shot 2 is very close to where you want to be, but maybe just needs some puck prep improvements. - Shot 3 is too fine as you say. - Shot 4 is either poor puck prep or a poorly put together blend.

            Comment


            • #8
              Both light roasts and VST baskets have reputations of being difficult to dial in.(I’m not sure about the Pullmans but I have put the VSTs back in the draw while I master the P64 and a new machine).
              Do you have another basket to try?

              Comment


              • #9
                Shot 1 looks like channelling to me.

                I have had no success with an 18gm dose in the 18gm VST in the Linea Mini. I've had to drop the dose to 17gm to allow some headroom. From there, it's all about puck preparation, as others have suggested above.

                Comment


                • #10
                  Is it a new grinder?
                  How much coffee have you put through it?
                  Have you ever been able to produce good shots with it?
                  Which burrs does the lagom have? The high uniformity?
                  Have you tried bypassing the pre infusion and pulling a
                  normal shot straight to full pressure?

                  Comment


                  • #11
                    Well Scotty now that Ive seen each of the vids ......let me first off retract most everything I posted up in #6 above.
                    No I wont edit it or anything out of that post.
                    So in post #6 other than the reference to multiple spout pours at the beginning of a shot that increases its
                    flow at a reasonable point earlier on, and into the pour which then becomes a single central spout pouring is fine ........
                    As for the rest disregard.

                    So have you run the LM no handle and measured / timed the flow rate at the 3bar pressure your using for P.I. ?
                    What is flow rate ? Weight / Time ?

                    Secondly and more importantly what age is the roast?
                    What year were the beans harvested and processed ?
                    Light roast age is?
                    Dark Roast ditto?

                    Shot 1 first blush of liquor shows around the 12 sec mark then the shot gushes badly after 1/2 way.
                    Crema is low & what I'd call beige! ...at best. Beans past their best. Seek a fresh roasted bean.
                    Overly tight grind to compensate for beans not holding up against the flow rate / pressure of the machine.

                    Shot 3, Now Ive seen the full screen shot / video you can see where the basket is not flowing fully and evenly.
                    I don't know you can call it channelling, as in the normal circumstance there would be spurting from the basket.
                    But it is definately showing uneven flow.
                    If you look further at shots No. 3&4 there is around 20sec of time before you see first flow of liquor.
                    That is a very long ramp up.
                    At the end of the shot the Crema is less and lacking for what should be expected from a 22g dose.
                    Also there are no hints of Hazelnut speckling which should be evident a good shot that achieves a good extraction ratio %.
                    Beans past their best and the grind is set too fine as a consequence to compensate.


                    Your LMLM is this the very same machine that Rick did first up as an R&D development?
                    Commissioned IIRC by sadly lost sponsor from this site - TC ?
                    I recall reading the post on here that Rick put up at the time. Cracking mods.
                    Are you confident its still running just as Rick had intended ?

                    And the water is inline with LM's specs ?
                    IYNA - LM's in general can be fickle, if not well maintained & particularly if not run on water that meets their spec's. Partially blocked Gicleurs and boiler issues are not totally uncommon on the multi group commercial machines at sites here in S.E. Qld.

                    In short As Aants suggests above ...if you haven't perfected a std 9bar shot yet, go back to it and restart there.
                    And known fresh dated well roasted beans !
                    Record all your grind settings for reference. And obv shot details.

                    Your nose should lead you from there.

                    i.e. a 20g basket / 9 bar - (time from when you activate the brew group)-
                    7-9 sec till first drips then a drippy shot that wants to pour, then onto a single spout pour about 1/3 of the way.
                    Around 40g out in 38 to 42sec total shot time (from brew activation )
                    Last edited by EspressoAdventurer; 27 May 2021, 01:46 PM.

                    Comment


                    • scotty595
                      scotty595 commented
                      Editing a comment
                      Answered a few down below, definitely making some progress!

                      Strange thing is the beans were quite new for the first 2 shots... the light roast was only 8 days past roast at the time of the video.

                      ---

                      Re the LMLM - it's not the first he did up as R&D, rather one I've recently had his kit installed on.

                  • #12
                    Thanks for all the help so far, I believe I've made some progress focussing more on puck prep and changing the beans!

                    Firstly, the light beans were quite new (9 days), the dark were quite old.

                    I went out and bought some medium roast fresh beans (3 days) and pulled decent looking shots with/without preinfusion.

                    Checked the flow rate and it was around 50ml for 10 seconds at ~9bar which seems quite low? But not sure if Rick's mod would have affected this though...

                    Here's a vid for reference (a few channeling/puck prep issues still)

                    No-Preinfusion (perhaps grind a little coarse here):


                    Preinfusion:

                    Comment


                    • #13
                      Originally posted by scotty595 View Post
                      Thanks for all the help so far, I believe I've made some progress focussing more on puck prep and changing the beans!
                      I went out and bought some medium roast fresh beans (3 days) and pulled decent looking shots with/without preinfusion.

                      Checked the flow rate and it was around 50ml for 10 seconds at ~9bar which seems quite low? But not sure if Rick's mod would have affected this though...
                      I'd take note of the taste. then lock them away till day 7. try again.
                      Theyre likely to keep improving thru day10 when you might be able to pull 40g in 40sec.

                      Sounds like your hot on the track of it now.
                      As for your light beans ,,,ive had light roasts that dont settle till around the 20-24 days.
                      But youve got to try, taste, rest, try again, all at your own pace with some roasts.

                      I wasnt nor would I in anyway question Rick Bonds mods/work in anyway. Nor was I in my prev post btw.
                      There's always details that can't be perceived in words on these posts.

                      Comment


                      • #14
                        Originally posted by EspressoAdventurer View Post

                        I'd take note of the taste. then lock them away till day 7. try again.
                        Theyre likely to keep improving thru day10 when you might be able to pull 40g in 40sec.

                        Sounds like your hot on the track of it now.
                        As for your light beans ,,,ive had light roasts that dont settle till around the 20-24 days.
                        But youve got to try, taste, rest, try again, all at your own pace with some roasts.

                        I wasnt nor would I in anyway question Rick Bonds mods/work in anyway. Nor was I in my prev post btw.
                        There's always details that can't be perceived in words on these posts.
                        Definitely wasn’t questioning Rick’s mod (he didn’t actually do the install for me as I’m Sydney based), but I had a chat to him on the phone and he said it sounds like my gicleur may be blocked up, as the flow rate shouldn’t be affected by his mod. Just grabbed a new gicleur and am in the process of installing it now!

                        Definitely needed some TLC:
                        Click image for larger version  Name:	BE8178FC-A74E-4886-89BA-348AF8BC43C6.jpeg Views:	0 Size:	292.1 KB ID:	867326

                        cleaned up nicely:
                        Click image for larger version

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ID:	867327

                        Comment


                        • #15
                          Scotty you will do yourself a big favour, longterm. Not just for the machine but also improvement in shot quality!

                          1/ Send a sample of your water to Bombora to analyse /report. Its free.
                          2/ Chase up the LM water specs.
                          It was in a recent thread of the GS3 guys on here.
                          Invest in quality filtration to the required spec.

                          As I said in a prev post I personally wouldn't run a LM outside of they're stated water specs.

                          Comment

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