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Thread: Watery extraction and low pressure on a coarser grind for older beans

  1. #1
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    Watery extraction and low pressure on a coarser grind for older beans

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    I get a few bags of beans delivered once a month usually about 1-2 weeks old by that stage.

    All seems good for the first bag and the first week or two. But by the second or third bag, where I've just opened it but they're now 3 or 4 weeks old, I get poor coffee.

    At a normal grind I get 9 bar pressure. On an older grind I won't get any extraction. But if I coarsen up the grind then I get a watery extraction AND fail to achieve pressure (it only reaches 5/6/7 if I'm lucky).

    Sometimes with slightly older beans (after a few days) I also fail to achieve pressure but get it right by coarsening up a little. But my observation for much older beans (though fresh in the packet) this doesn't work.

    Is is it possible to get anything useful out of month old beans still in the unopened pressure packet? I'd like to know if I'm doing something wrong.

  2. #2
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    Welcome to CoffeeSnobs,

    However you store your beans, they will be stale after about a month.

    Either buy smaller ammounts or get some green beans from BeanBay here and roast small ammounts in a popcorn popper like I do. That way I always have freshly roasted beans.

    I find that as my beans get older I have to grind them finer to get the pour between 25 to 30 seconds.

    Barry.
    Last edited by Barry_Duncan; 27th January 2017 at 04:59 PM.

  3. #3
    Senior Member LeroyC's Avatar
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    Watery extraction and low pressure on a coarser grind for older beans

    Unopened or not they're still starting to get a bit old at 4 weeks. There's plenty of coffees out there that are perfectly fine at 4 weeks after roasting, but you don't usually get much more than that. The problem is that as soon as you open that bag they will stale a lot faster than when they were only 1-2 weeks old. It sounds like this is what's happening here so if it's causing problems you'll be better off buying smaller amounts of coffee more often.

    Generally most coffees are at their best between 7 and 20 or so days after roasting. There are exceptions to this rule obviously and storage plays a part, but this is a good basic rule to follow.
    Dimal likes this.

  4. #4
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    Behmor Brazen - $249 - Free Freight
    Quote Originally Posted by Cody View Post
    I get a few bags of beans delivered once a month usually about 1-2 weeks old by that stage.
    All seems good for the first bag and the first week or two. But by the second or third bag, where I've just opened it but they're now 3 or 4 weeks old, I get poor coffee.
    At a normal grind I get 9 bar pressure. On an older grind I won't get any extraction. But if I coarsen up the grind then I get a watery extraction AND fail to achieve pressure (it only reaches 5/6/7 if I'm lucky).

    Sometimes with slightly older beans (after a few days) I also fail to achieve pressure but get it right by coarsening up a little. But my observation for much older beans (though fresh in the packet) this doesn't work.

    Is is it possible to get anything useful out of month old beans still in the unopened pressure packet? I'd like to know if I'm doing something wrong.
    I tend to find that even if you can get a reasonable looking pour out of beans >2 weeks old, the flavour just isn't the same and there is very little or no crema. They also seem to be much more prone to channelling.

    To shed some light on your observations - pressure and flow are both dependent on the resistance provided by the puck. Less resistance = more flow and a lower pressure. The resistance is dependent not only on grind size, but also on the viscosity (which depends on what/how much is extracted from the coffee) and probably also how much carbon dioxide there is.

    As the coffee ages, there are various chemical reactions occurring which impact the composition / concentration of the extracted material and thus the viscosity. There is also an off-gassing of CO2, which is why you get less crema.

    As the others have said, fresher is better (to a point).
    DesigningByCoffee and Dimal like this.



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