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  • EM480 static and channeling

    Hi Everyone,

    Im a Sunbeam Em6910/480 owner and am finding 90% of my shots have some sort of channeling, with obvious early blonding and wormholes in the puck. When this happens the puck is usually a bit mushy and wet when I remove the PF.

    Im wondering what sort of effect the noticable static and clumping of the em480 would be having on this and how to negate it as much as possible. Ive tried grinding directly in to the portafilter and also the little canister that came with the grinder. I am using a small plastic ruler to try and even out the grinds before I tamp and I use the NSEW method to tamp.

    Any suggestions?

    Thanks,
    ACog

  • #2
    Re: EM480 static and channeling

    hey acog

    maybe some of these things may help.

    1. mushy pucks can be a symptom of underdosing - not having enough coffee in the puck. try the collapse method where you tap the portafilter down on the bench/knockbox whatever to allows space for more coffee in the pf. grinding a little coarser, may help too.

    2. with clumping, some people like to do the weiss distribution method which is basically finding a needle or the like to stir the grinds in the pf before distributing and tamping. helps to break up clumps.

    3. where are the pinholes? in the middle or the sides of the puck? if at the side, then this might be a tamping/tamper issue. you using the nsew technique indicates to me that perhaps your tamper is not a snug fit for your portafilter. if theres too much space between the sides of your tamper and the basket then you may not be getting good side adhesion, and having the water travel down the sides of the basket.

    4. play with how you tamp - hard, soft, straight down with or without a polish, nsew, one tamp, two tamps and see what works for you and your machine.

    maybe some em6910 can shed some machine specific light down upon you.

    aaron

    Comment


    • #3
      Re: EM480 static and channeling

      dose more coffee into the PF and grind a little coarser, dont use a ruler to scrape the coffee and aim to get about 1/2 the steel from te SB tamper (if that is what you are using) above the PF. I always get soggy pucks when levelling the coffee in the PF with the 6910, but not when updosed.

      You say channelling, is this known through holes left in the puck or do you have a bottomless PF?

      the 6910 likes more coffee than most as the shower screen is quite high, leaving lots of room for lots of coffee.

      Sen

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      • #4
        Re: EM480 static and channeling

        As roknee and Senator said the Sunbeam doesnt like underdosing.

        The 0480 usually leaves some grounds behind in the chute but try this anyway......

        I use the double basket.

        Measure the beans into the basket level with the top of the basket.
        Feel the level with the centre of your palm.

        Grind the beans, fill the basket to a mound, settle with a few taps, add the rest of the grounds, tapping as needed so as to get them all in.

        Tamp, dont twist if using the Sunbeam tamper.

        Hopefully the tamper will be showing about half the metal as Senator said.

        Lock and pour.

        Comment


        • #5
          Re: EM480 static and channeling

          as with tg and senator -
          but Sen - only thing Id add at this point is that i think it IS important to have a flat, level surface of coffee before tamping.

          im talking about distribution here.

          if you want to cram in more coffe, then use the collapse method, but then distribute somehow: stockfleths, modded stockfleths; ruler or back of knife in circular motion, nsew motion etc (google and youtube)

          otherwise, if you have a mound of coffee and THEN tamp, there will be uneven density of coffee in the portafilter (therell be more coffee packed under the top of the mound than the perimter of the mound)

          aaron

          Comment


          • #6
            Re: EM480 static and channeling

            Agreed aaron.
            I left that point out.

            Comment


            • #7
              Re: EM480 static and channeling

              Hi Everyone,

              Thanks for the responses. A few answers:

              roknee, I have been underdosing, as the instructors at the SB coffee school said that the particular revision of Em6910 I have (the current one on the shelves) has a lower showerhead, and the silver of the tamper should be level with the top of the basket. I will try updosing slightly with a light knock or tamp and see if that gets rid of the soggies.

              The pinholes are generally in the middle of the puck, slightly off centre, not between the puck and basket. I am assuming this is channeling because of the holes and the sudden blonding about 5-10 seconds in. I dont have a bottomless PF.

              Ill also try the Weiss Distribution method and see if that sorts things out.

              Im using the tamper that comes with the unit. I would like a custom made one, but that will have to wait. I may try polishing the tamper to see if that improves the puck surfaces for now.

              One last thing, I have a 1kg bag of stale commercial beans. Is it worth wasting these on perfecting my grinding/tamping or will the stale qualities of the beans throw me off when I get back to the fresh ones? I nearly cry each time I have to pour a dud shot made from expensive beans down the drain.

              -ACog

              Comment


              • #8
                Re: EM480 static and channeling

                My thinking may be wrong here (and lack of experience), but if you compress the coffee with an even, flat tamp, how does the shape of the mound prior to the tamp effect the overall outcome, surely it "moulds" to the shape of the basket and the downward pressure applied spreads out the grounds evenly throughout the basket?

                Comment


                • #9
                  Re: EM480 static and channeling

                  hey acog
                  i know the frustration - i still have it at home with my machine despite getting nice pours at work. so many variables...

                  some more thoughts
                  1. "oily" beans clump more than less oily beans
                  2. polishing the puck doesnt always help, sometimes hinders (and i think i read that the SB tamper isnt good for polishing)
                  3. with the stalies, maybe theyre useful to experiment with your dosing levels. play around with collapsing once twice three times etc, and try things like grind collapse grind collapse Vs grind collapse collapse. try different tamp pressure heavy v med v light. bathroom scales are almost at the height of geekiness but a great learning tool helping to calibrate your arm...

                  aaron

                  "it wont happen overnight but it will happen"

                  Comment


                  • #10
                    Re: EM480 static and channeling

                    oh, and the problem I found with TGs method of dosing on my 480 (measuring the basket into the hopper and grinding) is that there was always beans left sitting on the top of the top burr, gravity it seems isnt enough to draw them thgough with my grinder.

                    Comment


                    • #11
                      Re: EM480 static and channeling

                      The 0480 isnt the best for that method i agree because it leaves a lot behind.

                      My MDF and Macap both leave almost nothing behind.


                      ACog the stale ones wont help as they behave differently to fresh beans.

                      Senator, Greg Pullman did a study on tamping and published the results here somewhere.
                      You might want to try search for it.

                      Comment


                      • #12
                        Re: EM480 static and channeling

                        Hi Everyone,

                        A bit of an update and one more question. Firstly, Ive taken everyones suggestions on board and am now updosing slightly by tapping on the bench then very lightly tamping before adding a bit more coffee. Im also using the Weiss Distribution technique to remove clumping.

                        While a little bit arduous, both the updosing and WDT have improved my shots remarkably and made them more consistent. So Thank You.

                        The strange thing however, is, I am still finding the shots seem to blond a bit early. (roughly around the 15 - 20 ml mark when pouring directly in to two separate shot glasses) It still tastes great, and has a nice mouthfeel (though could be thicker/heavier for my liking) and there are no wormholes or gaps beside the puck to suggest channeling. Is it perhaps my uneducated guess that its blonding too early? I read a vague reference in the forums to the temperature. Could this need adjusting?

                        Thanks

                        Comment


                        • #13
                          Re: EM480 static and channeling

                          Maybe try tamping on scales, bathroom scales will do, I have found to hard a tamp causes problems.

                          Comment


                          • #14
                            Re: EM480 static and channeling

                            I have bathroom scales that I occasionally tamp on. I try to hit around 15-20 kg.

                            Comment


                            • #15
                              Re: EM480 static and channeling

                              Originally posted by ACog link=1225755024/0#13 date=1226699809
                              I have bathroom scales that I occasionally tamp on. I try to hit around 15-20 kg.
                              1: Fresh beans... can not stress the difference that these make... Yes I can get reasonable shots from stale, but there are a few trick to it... So go fresh, before stressing too much..

                              2: I actually use a lighter tamp... Say about 8- 10kg at most and at work my thigh is my tamp base. :-X from behind people have commented that my whole stance and arm action is rather interesteng, unless you know what I am doing.

                              3: I have to play with the mix of what beans Vs freshness Vs how fine a grind AND to then decide on the tamp pressure.. This is the learning that you have to experience and what makes it all fun ;D

                              4: Polish you SB tamp... Get some fine emery paper (Sand paper to some) Mitre ten or Burnings etc of at least 600 and then 1200 grit and use a flat surface. Place the emery paper on the FLAT surface... and then using thumb and forefinger little circular movements with little pressure - start with the 600. Then as your doing this make sure you also moving your hand in a slower circular pattern.

                              I actually used 800 and then 1200 to add a fine polish. (these are harder to get).

                              Your tamp can then be used with the twist method and that will assist you. It also adds value to the SB tamp as the main issue then is Weight and the slight miss fit. Over all better that the plastic jobs.

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