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Thread: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

  1. #1
    Senior Member simonsk8r's Avatar
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    Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Ok, so the subject pretty much describes it ;). I just pulled a shot, BEAUTIFUL pour, 60ml in roughly 31 seconds. Next shot, SAME variables, same grind setting, same distribution method, same tamp style, chuck it in, gushes out 60ml in 16 seconds!

    Yeah, i know! Sometimes I just dont get it... :S Still tasted amazing though which was odd... I cant think of why this happened really... The pour started off with nice tiger-striping, then the stream got really really thick on one side but was dripping slowly out the other, then both sides it was just streaming! Was like it had a mood swing!


    Any ideas for a confused fellow??

    P.S. Beans are fresh, about 1 week ago they were roasted.

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    Mal Dimal's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Despite your believing that all variables remained the same, something must have been different.... :-?

    How do you use your grinder, for example? Do you half fill the bean-hopper before grinding? Only spoon-in the beans needed for each shot? Spoon-feeding the grinder can result in slightly coarser grind size than when the hopper is well stocked.

    The tamping force shouldnt be a biggie in the overall scheme of things but certainly dose and distribution is. You may need to examine your technique and the process you use in fine detail, just to make sure.... ;)

    Mal.

  3. #3
    Senior Member GregWormald's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 372D292B2A372F7C36440 link=1275978291/0#0 date=1275978291
    The pour started off with nice tiger-striping, then the stream got really really thick on one side but was dripping slowly out the other
    You may have used the same distribution method, but this says to me that its not working!

    Greg

  4. #4
    Senior Member simonsk8r's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Despite your believing that all variables remained the same, something must have been different....
    Yeah something had to have been different... but i cant pick what it was... My method of grinding is weighing out about 21grams of beans and grinding it all, and as its grinding im free dosing it (constantly flicking the lever) while rotating the portafilter around so that it goes all round the basket. When its full, i collapse it once, top it up, sweep it level and tamp. (i try to alter my distribution style at times depending on the pour, but this time i did this).

    Hmmm.. well when i grind it, there is usually about 3-4 grams of ground coffee still in the doser, and when i had my next coffee an hour or so later (the bad pour one), i usually use the leftover grinds in the doser from an hour or so ago... SURELY the grinds dont go bad in that space of a time?? :S

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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    So given were now in winter, Ive got a possibility. You didnt happen to turn your heater on between the first & second shots did you? Room temperature makes a massive difference to your shots, and a shot will pull tighter/slower in a colder room when compared to a warmer room.

    This is often most noticeable in our place when I pour a shot first thing in the morning when the kitchen is freezing, and another at night when weve had the heater on for a couple of hours after work & feel like a coffee after dinner.

    The other option is that your dose/tamping technique needs a little work & youre getting severe channeling. Could happen for example if when you lock the group head in that you break the surface of the puck (too much coffee in it). Try dosing a little lower & see if that helps with consistency.

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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 312B2F2D2C31297A30420 link=1275978291/3#3 date=1275989572
    Hmmm.. well when i grind it, there is usually about 3-4 grams of ground coffee still in the doser, and when i had my next coffee an hour or so later (the bad pour one), i usually use the leftover grinds in the doser from an hour or so ago... SURELY the grinds dont go bad in that space of a time?? :S
    I think this is your answer right here.

    YES .. the one hour old grinds will make a difference.

  7. #7
    Senior Member simonsk8r's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 627561606E060 link=1275978291/4#4 date=1275991109
    You didnt happen to turn your heater on between the first & second shots did you?
    Nope no heater being switched on/off...

    Quote Originally Posted by 627561606E060 link=1275978291/4#4 date=1275991109
    The other option is that your dose/tamping technique needs a little work & youre getting severe channeling.Could happen for example if when you lock the group head in that you break the surface of the puck (too much coffee in it).Try dosing a little lower & see if that helps with consistency.
    Yeah its possible... I will give this a shot! (no pun intended :D )

    Quote Originally Posted by 6773596234060 link=1275978291/5#5 date=1275991403
    I think this is your answer right here.

    YES .. the one hour old grinds will make a difference.
    Really? I generally thought people exaggerated just a tad when they emphasise not to buy pre-ground coffee haha... just to make their point ;)

    But do the grinds really go stale or change in some way in that period of time?? :S

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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 203A3E3C3D20386B21530 link=1275978291/6#6 date=1275992366
    But do the grinds really go stale or change in some way in that period of time?? :S
    Absolutely! If I have a quiet 10 mins or so I always run a bit of coffee through the grinder and dump it as it will not perform the same. The shot always runs faster with stale grinds.

  9. #9
    Senior Member simonsk8r's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Wow... I wasnt aware of this.. Having done all the research Ive done youd think I would be! :P
    It just seems outrageous that it can change that quickly! Knowing that, I will definitely not use the slightly-old grinds haha...

    Thanks guys! Very happy camper now! :D

  10. #10
    Sleep is overrated Thundergod's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 342E2A2829342C7F35470 link=1275978291/8#8 date=1275993580
    It just seems outrageous that it can change that quickly!
    Time is relative.

    An hour is a long time to ground coffee.

    Prove it to yourself.
    Grind enough for a shot and put it aside for an hour.
    Then load it into the basket and run the shot.

  11. #11
    Senior Member simonsk8r's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Yes true.. I guess i meant that I wasnt aware that ground coffee was a substance that had that short a lifespan so to speak. I knew it cut its freshness and use down, but wasnt aware it was that quickly. Its okay I trust yall ;)

    Thanks everyone :)

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    Senior Member simonsk8r's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Okay! So another scenario! ;)

    I just dosed basket, weighed the basket and it had about 16grams of coffee in it. Pulled shot, great pour, roughly 60ml double in 30seconds.

    This time I wanted to try a different basket (as I have this old basket in which i enlarged the holes accidentally trying to poke a pin through to clean it. ANYWAYS...). I mainly wanted to see whether the old basket could hold more coffee in it because the sizes between the new and old seemed to look different.. so i tested it out.

    The old basket held about 18grams of coffee, so it seemed to hold more. YET the pour was horrible! Blonded fair early, reached 60ml double in about 18 seconds! (Btw, same grind setting, dosing and distribution method, same tamp...)

    :O:O:O :(:(:(

    SURELY it cant be the enlarged holes in the bottom? Theyre not overly big, but wouldnt the rate of flow relate directly to the resistance of the water through the coffee, and not the holes in the bottom?? This doesnt make ANY sense! (And the grinder was cleared of most old grinds before pulling the next shot...)

    ? Youd think the older basket would have presented a slower pour due to more coffee in the basket...?

  13. #13
    A_M
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    What sort of baskets are you talking about..

    Double floor or Single.

    1: 60ml .. Sorry toss it in teh sink...

    2: And yes be it a single or double floor basket any change in hole sizes will have a significant impact on flow rate... Simple physics 101.


    Now stop with the numbers and just make a coffee.. Until you forget teh numbers grasshoper; you will never move forward.....

    Coffee is an art; not pure maths... Regardless of what the marketing and some PR people might tell you...

    2 + 2 = 5 wher 5 = great coffee Note: If 2 + 2 = 4 then you have it all wrong 8-)

  14. #14
    Senior Member simonsk8r's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 644B42405768444B44424048404B51250 link=1275978291/12#12 date=1276940735
    What sort of baskets are you talking about..
    Theyre both double-baskets, yet they are both differently shaped to one another, and i did a test to see whether they produced the same pour.
    Quote Originally Posted by 644B42405768444B44424048404B51250 link=1275978291/12#12 date=1276940735
    1: 60ml .. Sorry toss it in the sink...
    Not sure I understand... Isnt 60ml a double shot? I was aiming for that.
    Quote Originally Posted by 644B42405768444B44424048404B51250 link=1275978291/12#12 date=1276940735
    2: And yes be it a single or double floor basket any change in hole sizes will have a significant impact on flow rate... Simple physics 101.
    And now that I think about that yeah the bigger holes here and there would cause a faster flow rate... So im guessing this would be the culprit? (Its only say... 6 or 7 holes enlarged, but that would still make the difference :P)

    Quote Originally Posted by 644B42405768444B44424048404B51250 link=1275978291/12#12 date=1276940735
    Now stop with the numbers and just make a coffee..Until you forget the numbers grasshoper; you will never move forward.....
    I guess I still have this to learn... but you have to admit that it still involves numbers and measurable methodologies to a certain degree? :)

    Thanks heaps AM :)

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    A_M
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Quote Originally Posted by 3B212527263B23703A480 link=1275978291/13#13 date=1276943178
    Theyre both double-baskets,
    Single or double floor ?

    Quote Originally Posted by 3B212527263B23703A480 link=1275978291/13#13 date=1276943178
    Its only say... 6 or 7 holes enlarged
    WHY would you need to try to clean the holes on a standard basket...


    The only time is when your using a pressurised (double floor) basket and even then you might as well toss it.


    Quote Originally Posted by 3B212527263B23703A480 link=1275978291/13#13 date=1276943178
    Isnt 60ml a double shot?
    Not if it tasts like crap.. *For me 50ml is norm and 55ml at a pinch... But have not measured in many many months... *

    If you went up to most systems and stuch a measuring container under and measured.. *1 in 10 or 15 might on the money... And I bet most of those would tast like crap..


    Quote Originally Posted by 3B212527263B23703A480 link=1275978291/13#13 date=1276943178
    but you have to admit that it still involves numbers and measurable methodologies to a certain degree?
    No not really... *A painter looks and feels the colour... Looking at a chart and picking a colour as per the RGY *ratio will not give the required outcome.. *Numbers are a guide.. As soon as you reference them you LOOSE.

    It was hot today... *YES

    It was 31.74C .... * So WHAT... * Context is missing...

    Mike, *Renzo and I were playing *and while we got down to some fine measurements at one stage ... It was all about touch / look and feel..

    Hard to explain but Mike will confirm... The test gear really did little; other than allow us to tick a box... *Only box we did not tick was the GRINDER one *;D

    (HINT *http://coffeesnobs.com.au/YaBB.pl?num=1274427912 )

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    Mal Dimal's Avatar
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    Re: Pull shot.. great! Pull next shot.. whoooa waterfalls ahead!

    Behmor Brazen - $249 - Free Freight
    Quote Originally Posted by 3E242022233E26753F4D0 link=1275978291/13#13 date=1276943178
    And now that I think about that yeah the bigger holes here and there would cause a faster flow rate... *So im guessing this would be the culprit? (Its only say... 6 or 7 holes enlarged, but that would still make the difference :P)
    Would definitely be contributing to the problem Simon.....

    Typically, with a decent double basket fitted (NO Coffee), the resistance to water flow will raise the pressure to ~3 BAR at the Group Head. It is only reasonable to assume that increasing the size of some of these holes will allow for increased flow and thereby decrease the pressure at the Group Head. Another effect would be, that if the holes are even slightly grouped together, to encourage channelling within the proximity of the larger holes and lead to early blonding due to poor extraction of the coffee at this site.

    A "Rule of Thumb" relating to Water Flow... For every 50% increase in diameter of an orifice, the Water Flow Rate will Double at the same Delivery Pressure. Conversely, for every 50% increase in the size of an orifice where the Flow Rate remains the same, the Delivery Pressure will be Halved.

    Even though the Coffee Cake provides the majority of resistance to Water Flow, the Basket Holes also do their bit.... ;)

    Mal.



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