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Thread: Anyone else ramping down pressure?

  1. #1
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    Anyone else ramping down pressure?

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    https://youtu.be/j5P3Rjv1zR8

    I've found this to increase chocolatey flavours significantly.

    - Almost 10 seconds pre-infusion with gradual ramp up to 10 bar,
    - About 20 seconds extraction at 10 bar,
    - About 10 seconds pressure ramp down to 2 bar.

    I'm using a cheap $25/kilo roast that is now at 3-4 weeks.

    I apologise profusely for the disgracefully filthy cup.

  2. #2
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    Yes, always
    1.jpeg

  3. #3
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    Quote Originally Posted by DamianB View Post
    Yes, always
    1.jpeg
    What machine Damian?

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    Decent Espresso
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  5. #5
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    Why the massive pressure spike early on?

    If you had a look at any E61 Expobar, the ramp up is very gradual,

  6. #6
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    The blue line is pump water flow, not pressure
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  7. #7
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    Quote Originally Posted by DamianB View Post
    The blue line is pump water flow, not pressure
    Ah, gotcha, makes sense now.

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    Quote Originally Posted by BobSac View Post
    Ah, gotcha, makes sense now.
    ... and the brown line is the actual weight hitting the cup. Which kinda shows how measuring the input bears little relationship to the actual pour (i.e. brown line).

    Hey DamianB - looks like a pretty good shot.

    Enjoy your cuppa - let taste be the guide.

    TampIt

  9. #9
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    Quote Originally Posted by TampIt View Post
    ... and the brown line is the actual weight hitting the cup. Which kinda shows how measuring the input bears little relationship to the actual pour (i.e. brown line)
    The flow out can be predicted by the flow in, I’ve programmed a ‘stop at volume’ that does so

  10. #10
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    Iíve tried a number of different profiles, including a slow taper at the tail of the shot

    Iím finding the best results with a sudden cut from 9 bar as opposed to a ramp down.


    The long slow preinfusion at the start is definitely good though. Allows a finer grind and produces fantastic flavours.

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    Quote Originally Posted by herzog View Post
    The long slow preinfusion at the start is definitely good though. Allows a finer grind and produces fantastic flavours.
    Depends what you refer to as preinfusion, the term is mostly miss used IMO.
    Pre, meaning prior to infusion, is the action of adding water prior to it soaking into or infusing the grinds.
    Preinfusion in this respect has no impact on puck compression, hence grind size. But a fast preinfusion can help with a more even infusion, extraction, less channeling.
    But if your referring to infusion as preinfusion, then you are correct, a slow infusion time, and even a pause can increase flavours and yield %. And a slower time from preinfusion to max pressure will compact the puck less, giving less puck resistance, mean a faster flow or allow a finer grind for the same flow rate.
    In my experience, a finer grind isn’t always better, at a point, going finer starts to looses flavour and body. In saying that, the ideal grind for me is quite fine.

  12. #12
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    ^if you can get the grind finer without any brewing defects, it will taste better. however, you can only go so fine before water stops flowing through the puck evenly and begins channeling - leading to an unevenly-extracted coffee suffering from poor flavour and body, as you say. a properly-preinfused puck will resist water less - so you have the opportunity to grind finer and get the same contact time, extract more, and get more tasty from the coffee.
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  13. #13
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    Quote Originally Posted by woodhouse View Post
    ^if you can get the grind finer without any brewing defects, it will taste better. however, you can only go so fine before water stops flowing through the puck evenly and begins channeling
    Your theory makes sense, but I am unable to prove it, I can grind finer with out being able to determine any increased channeling. I'm not getting over extracted tastes or any sign of uneven extraction, no uneven colour through out the puck, even flow out of the basket, etc.... flavours are the same just lower TDS, weeker taste and less body/mouthfeel.
    I agree, going finer is better, till a cretain point then the reverse applies. For me that point can be slightly finer for older beans and for some bean types than others.
    FWIW, I'm typically getting EY of 24 to 26%

  14. #14
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    Quote Originally Posted by DamianB View Post
    Your theory makes sense, but I am unable to prove it, I can grind finer with out being able to determine any increased channeling. I'm not getting over extracted tastes or any sign of uneven extraction, no uneven colour through out the puck, even flow out of the basket, etc.... flavours are the same just lower TDS, weeker taste and less body/mouthfeel.
    I agree, going finer is better, till a cretain point then the reverse applies. For me that point can be slightly finer for older beans and for some bean types than others.
    FWIW, I'm typically getting EY of 24 to 26%
    hmm, that's interesting. looking forward to getting my decent so i can investigate.

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    When I'm going to ramp down, I stop the full pressure extraction a couple of seconds early, usually just as the blonding is about to begin.

    As a test, to determine the kind of tastes I'm adding to the result with a ramp down, I switch out the cup to taste what the last few seconds of the extraction are like.

    To me the ramp down (on my particular machine with my particular beans in my particular grinder at my settings /end disclaimer) adds a bit of smokey sweetness.

  16. #16
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    Using my current machine - Lelit Bianca - to do this very thing and loving it.

    charlie
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  17. #17
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    Quote Originally Posted by DamianB View Post
    Depends what you refer to as preinfusion, the term is mostly miss used IMO.
    Pre, meaning prior to infusion, is the action of adding water prior to it soaking into or infusing the grinds.
    Preinfusion in this respect has no impact on puck compression, hence grind size. But a fast preinfusion can help with a more even infusion, extraction, less channeling.
    But if your referring to infusion as preinfusion, then you are correct, a slow infusion time, and even a pause can increase flavours and yield %. And a slower time from preinfusion to max pressure will compact the puck less, giving less puck resistance, mean a faster flow or allow a finer grind for the same flow rate.
    In my experience, a finer grind isnít always better, at a point, going finer starts to looses flavour and body. In saying that, the ideal grind for me is quite fine.
    My understanding of the term preinfusion has always been infusion/damping of the puck under low pressure prior to extraction, after the predetermined time, let the extraction begin.

    If we want to be pedantic I guess we could say that the word predetermined refers to an act that takes place prior to it being determined.

  18. #18
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    I think the majority have the same interpretation. The problem for me is, it creates confusing discussions.
    For you it may seem pedantic, for me it is not so minor.
    The process proir to rise to pressure has two very individual steps, which have very different influences, either of which have probably more impact on the resulting extraction than any other part of the proceedure.

  19. #19
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    The slow ramp up of the Expobar that saturates the cake/puck is what sold me on the Expobar.

    I was about to purchase a Rocket Appartomento when I used both and preferred the Expobar taste, same grinder, same beans (the $500 saving and the toned down brand advertising was a bonus).
    Last edited by BobSac; 1 Week Ago at 10:49 PM.
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