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Thread: Naked Extraction Diagnosis - dead spot in the middle

  1. #1
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    Naked Extraction Diagnosis - dead spot in the middle

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Ive tried dosing differently, but I always seem to get a dead spot in the middle.

    Sometimes water (not coffee water) will shoot out of one of basket holes on the outer edge - its bizarre and I cant figure out why!




  2. #2
    Senior Member Dennis's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Just ideas...

    The water channeling happens because it has found an immediate escape route down between the side of the puck and the basket. There isnt even time for the water to extract coffee before it escapes.

    Re the dead spot, have you tried using a different basket? Might have nothing to do with technique and everything to do with uniformity of the bottom of the basket?

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Unfortunately, my custom Pullman is sized to my Synesso basket (which is almost 59mm) and so I cant use any other baskets as the tamper wont fit.

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Have you tried this?:
    http://www.home-barista.com/weiss-distribution-technique.html

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    Senior Member trentski's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    I got better results from my naked portafilter when I rotated the basket 180 degrees half way through filling it :o

    Do you have a mound of coffee in the middle of the basket before you tamp or is it flat?
    Have you tried convexing it with your finger before you tamp?

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Quote Originally Posted by 49607261646B6B6C60050 link=1307757722/3#3 date=1308548363
    Have you tried this?:
    http://www.home-barista.com/weiss-distribution-technique.html
    I ruled out the Weiss Distribution Technique as it was not repeatable in high volume situations.

    I am getting better distribution now that Ive switched back to the Synesso basket, so I think its actually just the basket, but will try convex method too.

    Thanks, guys!

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Just out of interest, what was extraction time/volume?

    I only ask because judging by the photo the extraction volume looks to be a little high.

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Quote Originally Posted by 3B3D2A213B3C24264F0 link=1307757722/4#4 date=1308549818
    Have you tried convexing it with your finger before you tamp?
    Newb question...but what does this mean?

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    Senior Member trentski's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    make a dish in the coffee grounds so the middle is lower than the outside. So when you tamp, the middle of the puck is compressed less than the edges (or even better, evenly). It is possible that the middle is compressed more than the edges leading to the pattern we see in tashies photo.

    I get better results from using the basket that came with my gpp plus over aftermarket baskets.

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    Bean Powered Member jaybee's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    My pours always start from the outside and move inwads just as yours has. If the tamp is too firm I find, like you, that the two or three streams of coffee dont quite manage to merge.

    Im not convinced that the 5mm gap between the shower head and the portafilter is a good design feature on the E61 head - it seems to encourage channelling and this sort of pattern. Of course the Europeans tend to use a strongly convex tamper, not flat which is our norm.

    Forgiving all its other sins, my EM6910 did a more reliable job...

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    Senior Member trentski's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    HI Jaybee,

    I also have a Giotto Premium Plus and a naked portafilter ?(which I use to check technique every now and then). I graduated from a Rancilio Lucy.

    I would often get a uniform pour and occasionally I would get a pour that started at the edges and then moved to the centre of the basket. I grind, smooth off and tamp lightly, no tapping, no double tamping as I have seen some do (dose, tap, tamp, dose tap , tamp, pour). With the Synesso basket I was using I couldnt get a decent pour to save myself, but using the one that came with the Giotto Premium Plus I get good results, so much so that I was confident to put away the naked and grab the more convenient twin spout handle.

    The Giotto Premium Plus is a whole lot more forgiving than Lucy/Silvia, you get great results without having to be "on your game" all the time.

    I dont leave a 5mm gap between the showerhead and the puck though.


    Think about this, if the E-61 was such a flawed design, why is it the design of choice amongst the majority of the high end espresso machines?


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    Bean Powered Member jaybee's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Quote Originally Posted by 4345525943445C5E370 link=1307757722/10#10 date=1308634055
    I dont leave a 5mm gap between the showerhead and the puck though.


    Think about this, if the E-61 was such a flawed design, why is it the design of choice amongst the majority of the high end espresso machines?
    Sorry, I was referring to the vertical gap to the sides rather than the horizontal expansion space.

    Pretty much everything has a design issue somewhere - being the most used doesnt make it above comment. But neither did I say that that issue was a showstopper - Just an issue.

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    [QUOTE=78736B707777120 link=1307757722/11#11 date=1308638848]
    Quote Originally Posted by 4345525943445C5E370 link=1307757722/10#10 date=1308634055
    Sorry, I was referring to the vertical gap to the sides rather than the horizontal expansion space.
    Do you mean the difference between the O.D. of the Filter Basket Walls and the I.D. of the Group Handle space?

    If this is what you mean, Ive used machines where this "gap" has been both larger and smaller and this has not made the slightest difference to the quality of the pour. Pour quality and the result in the cup, has always come down to the refinement of technique for each particular machine.... :-?

    Mal.

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    Bean Powered Member jaybee's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Quote Originally Posted by 7B56525E533F0 link=1307757722/12#12 date=1308640739
    has always come down to the refinement of technique for each particular machine....
    <Mischief mode on>
    I have a ladder with a broken rung. I have refined my technique to the point where the broken rung is hardly noticable. Its still got a broken rung though!
    </Mischief mode off>

    Actually, I may be on to something (although the 5mm was a bit of an exageration!) - because I have graduated from a 6910, my tamper is sized up for the sunbeam or synesso baskets which are nearly a mm wider at the mouth. When I bought the Rocket, I naturally took the baskets over as the tamper doesnt fit the narrower stock baskets. In several years of 6910 use I have NEVER had a channel. I have had several whilst dialing in the Rocket, although none since I got the technique honed. I guess that my tamper is off back to Greg to be re-sized so I can use the std baskets!

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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Compared to the likes of many of our Pros, I have had experience on very few machines.

    However, apart from a few failures when I kicked off with my first "real" espresso machine and came to understand the aspects of my technique that were letting me down, I have never experienced anything other than excellence from subsequent machines Ive owned, unless I did something wrong, it was never the machines fault...

    After all, the process isnt really rocket science and if you need to migrate from one machine to another, learn how to use it properly and then move on to bigger and better things...

    Dont blame the machine..... ;)

    Mal.

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    Senior Member trentski's Avatar
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Quote Originally Posted by 6944404C412D0 link=1307757722/14#14 date=1308662122
    the process isnt really rocket science

    Unless you own a Rocket Giotto that is ;D

  17. #17
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    Re: Naked Extraction Diagnosis - dead spot in the middle

    Quote Originally Posted by 6F697E756F6870721B0 link=1307757722/15#15 date=1308699339
    Unless you own a Rocket Giotto that is ;D
    Thought I mightve left myself open for that one.... :P ;D

    Mal.

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    Re: Naked Extraction Diagnosis - dead spot in the middle

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    If youre getting a dead spot in the middle it might be because youre tapping your tamper on the side of the portafilter to dislodge any wayward grinds. However in doing this you may be creating a small space between the portafilter and coffee puck and hence a channel of small or no resistance for water to run through, instead of being pushed through your coffee.



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