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Leakage from my bottom when I pull my lever.....

Hmm.. there’s Gotta be a better way of saying that.....

So... beans are fresh, grinder is great quality and fairly new (Robur like 12 months old) but I’m getting leakage from the basket at the pre-infusion stage. The beans seem nicely roasted and are 7 days post. When did channeling become my problem and how? How do you folks deal with channeling especially guys like me who have a big lever (compensation much???)

Comments

  • It’s a process of elimination First thing that comes to mind on the leaking is the group head seal With regards to channeling it’s probably the height of the compressed puck (The technical reason ) Lever machines tend to have a suction effect on the puck So when you pull the lever the whole puck is momentarily lifted intact, then goes back into its place If the height on the pressed puck in the basket is at its optimum height level then it’s minimised or eliminated If it’s not, the lifting action can crack the pressed puck KK
  • I should also note on bean roast depth Beans that are roasted light may not have as good a binding affect when ground & tamped so water under pressure will find a weak spot KK
  • All great things to consider... cheers KK! I’m thinking there maybe an issue with my distribution being slack. I’m not paying for one of those WDT things as a home-made job I saw recently was far superior and a fraction of the gouge. Ideas folks?
  • Update for the two peeps and three bots reading..... :D I’ve been using an OCD distribution thingy for the last couple of days and it seems to have alleviated the issue. Seems my distribution was lax, bad habits etc. Anyway, if you’re looking for a really expensive way to solve a simple problem.... my pleasure :P
  • And I thought my suggestions were on point Never mind Next time pop over and I can show you how it’s done without tools the koffee Kosmo way  :D KK
  • I wasn't gonna comment as I thought it was more a question about channelling with a lever machine (of which I know zilch about!), but I've got one of the cheapo spinny distribution tools and it works really well once you set the depth right. Would love to know how deep you set yours, I think I've nutted out that it works best when it's set deep enough to have a slight tamping effect, but not so deep that there's no compression when you tamp. 2-3mm of compression when you actually tamp after. I really feel the grinder makes a difference too, with a few of my previous grinders it would be a bit clumpy, and I had to rotate through various distribution methods, never really finding one-fits-all, but my current grinder there are no clumps, grind is fluffy, and distribution is so much easier. I know there's debate about whether clumps really makes a difference, but it really seems to I  my experience. Maybe not so much that they 'stick around' after tamping as they get squashed out, but getting good distribution seems to be hampered by big clumps and boulders.
  • on 1555672685:
    And I thought my suggestions were on point Never mind Next time pop over and I can show you how it’s done without tools the koffee Kosmo way  :D KK
    Superb idea! I think your comment about the darker roasts was particularly on-point.
  • on 1555680362:
    I wasn't gonna comment as I thought it was more a question about channelling with a lever machine (of which I know zilch about!), but I've got one of the cheapo spinny distribution tools and it works really well once you set the depth right. Would love to know how deep you set yours, I think I've nutted out that it works best when it's set deep enough to have a slight tamping effect, but not so deep that there's no compression when you tamp. 2-3mm of compression when you actually tamp after. I really feel the grinder makes a difference too, with a few of my previous grinders it would be a bit clumpy, and I had to rotate through various distribution methods, never really finding one-fits-all, but my current grinder there are no clumps, grind is fluffy, and distribution is so much easier. I know there's debate about whether clumps really makes a difference, but it really seems to I  my experience. Maybe not so much that they 'stick around' after tamping as they get squashed out, but getting good distribution seems to be hampered by big clumps and boulders.
    I think channeling in levers is exacerbated by our predilection for larger baskets and the rough way the puck is treated by the abduction of the piston. Add a lighter roast (thank you KK) and dodgy distribution and it’s a recipe for blurk! I reckon I compress 3mm after the OCD tool and it’s a very nice even feeling compaction.
  • I found that I had to rinse the baskets and back wash often using the Bosco 4 group lever, and that dark(er) roasts tended to trap oils pretty badly, so again constant rinse and back wash / back flush was required - plus they dont tend to like updosing - so that's always an important consideration Pat
  • Some coffees Brett are pre-disposed to exacerbating channeling. It's been a long journey for me over 40 years, but I can now put that "phenomenon" aside and know how to deal with it. The extraction method (lever versus pump) won't make it much worse, I've found that some coffees, regardless of the roast profile, will promote a degree of channeling. It's got to do with a concept called abnormal Water Activity and it's impact upon both the roasting process and the espresso extraction. The cell structure of the coffee is not right.....and hence when it's ground the particles are literally "all over the place". In the last few years I've had some green coffees with abnormal water activity (these have been returned to sender). I had no measurement method at the time (still don't, but I know the key signs of abnormal water activity as it roasts outside of the standard params). Water activity in relation to green coffee is a science more advanced than moisture and density traditionally used by all parties in the raw coffee supply chain. In the roaster, abnormal water activity (depending upon which end of the spectrum it's at) would either roast with no heat, or excessive heat (normally it's a combination of unripes + abnormal water activity). In the grinder, the roasted coffee has a tendency to choke or gush with very little tolerance in between (and a lot of frustration by the operator). In the cup, it's bland, boring and lacking just about everything - no flavour, no acids, no body, no wow !. Abnormal water activity can be common in green (raw) coffees. It's caused by improper drying of the greens during processing. Thing is, you can look at the coffee, smell the coffee, test it's moisture and density and with all the green ticks, proceed to roast it and "wowza.....something's not right". Most of the bigger green brokers are scrambling to get water activity measurements on coffee. Why ? because the green coffee when it's abnormal must be used or roasted ASAP. The longer it's sitting around in a warehouse, the more problematic it becomes. So, getting back to your channeling issue - it can be from the roast and/or it can be from the greens. Yes, technique plays a role in the process and the likes of dosing tools can help "compensate" for problems and in the absence of roast "data" I'd say the coffee might have something that's promoting channeling like abnormal water activity. In reality, the likelihood of a roast profile defect is higher than a defect of the raw coffee. Some coffees are difficult to work with......we know that already..........Brazil and Ethiopian naturals, some high grade Kenyans and washed Ethiopians, Sumatrans, Monsooned coffees - all present challenges in espresso extraction if the roast has not been absolutely nailed. A good barista or operator can identify when there is something wrong - extractions that are choking too easily, the need to adjust the grinder way out of the norm, etc. all these point to roasts or water activity that's not ideal. When there is a Water Activity issue, no amount of supa-dupa roasting skill is going to polish it into something that's acceptable or normal - trust me, I've tried and tried 1,000's of times over. Happy Easter.
  • on 1555746008:
    Some coffees Brett are pre-disposed to exacerbating channeling. It's been a long journey for me over 40 years, but I can now put that "phenomenon" aside and know how to deal with it. The extraction method (lever versus pump) won't make it much worse, I've found that some coffees, regardless of the roast profile, will promote a degree of channeling. It's got to do with a concept called abnormal Water Activity and it's impact upon both the roasting process and the espresso extraction. The cell structure of the coffee is not right.....and hence when it's ground the particles are literally "all over the place". In the last few years I've had some green coffees with abnormal water activity (these have been returned to sender). I had no measurement method at the time (still don't, but I know the key signs of abnormal water activity as it roasts outside of the standard params). Water activity in relation to green coffee is a science more advanced than moisture and density traditionally used by all parties in the raw coffee supply chain. In the roaster, abnormal water activity (depending upon which end of the spectrum it's at) would either roast with no heat, or excessive heat (normally it's a combination of unripes + abnormal water activity). In the grinder, the roasted coffee has a tendency to choke or gush with very little tolerance in between (and a lot of frustration by the operator). In the cup, it's bland, boring and lacking just about everything - no flavour, no acids, no body, no wow !. Abnormal water activity can be common in green (raw) coffees. It's caused by improper drying of the greens during processing. Thing is, you can look at the coffee, smell the coffee, test it's moisture and density and with all the green ticks, proceed to roast it and "wowza.....something's not right". Most of the bigger green brokers are scrambling to get water activity measurements on coffee. Why ? because the green coffee when it's abnormal must be used or roasted ASAP. The longer it's sitting around in a warehouse, the more problematic it becomes. So, getting back to your channeling issue - it can be from the roast and/or it can be from the greens. Yes, technique plays a role in the process and the likes of dosing tools can help "compensate" for problems and in the absence of roast "data" I'd say the coffee might have something that's promoting channeling like abnormal water activity. In reality, the likelihood of a roast profile defect is higher than a defect of the raw coffee. Some coffees are difficult to work with......we know that already..........Brazil and Ethiopian naturals, some high grade Kenyans and washed Ethiopians, Sumatrans, Monsooned coffees - all present challenges in espresso extraction if the roast has not been absolutely nailed. A good barista or operator can identify when there is something wrong - extractions that are choking too easily, the need to adjust the grinder way out of the norm, etc. all these point to roasts or water activity that's not ideal. When there is a Water Activity issue, no amount of supa-dupa roasting skill is going to polish it into something that's acceptable or normal - trust me, I've tried and tried 1,000's of times over. Happy Easter.
    Didn't know that Jeff, fascinating! I always thought it was for sure something in the roast or most likely technique-related (or machine pump malfunction). But makes sense that if the green bean isn't right from the start then nothing much you can do can fix that.
  • Thanks Jeff for your unique take on this it is illuminating as always! Pat
  • I have read about such a phenomenon that Jeff described However I have not experienced it myself That’s why I mentioned in my earlier post about the poor binding effect of the coffee grounds when tamped KK
  • Wow Jeff, thank you! Extraordinary insight! You’ve perfectly articulated what’s been happening. The beans I’ve been using from a sydney supplier haven’t been ‘quite right’. The latest batch I’ve started using from ICT have no issue (expensive new toy notwithstanding) and now I know, I can relegate temperamental Beans to the work plunger. Happy Easter
  • on 1555765005:
    I have read about such a phenomenon that Jeff described However I have not experienced it myself That’s why I mentioned in my earlier post about the poor binding effect of the coffee grounds when tamped KK
    Absolutely.  I was thinking roast defects and slackness yet nothing had changed except the result! Jeff I think has nailed my particular situation.
  • Any photos to better identify what it is that you are experiencing?

  • Nup, Jeff from MyCuppa was spot on with his assessment. Changed bean supplier, problem never reappeared.

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