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Thread: Cyangugu, gushes even at a fine grind & bitter.

  1. #1
    Senior Member speleomike's Avatar
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    Cyangugu, gushes even at a fine grind & bitter.

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi all
    Lat week I roasted the Rwandan Cyangugu in my Gene Cafe and just tried it tonight. It gushes out real fast and I had to reduce the grind to 3 on the Rocky but its still gushing. As the cup is filled within 15 seconds I have to end early and its undrinkable.

    Roast: Cyangugu 100 grams, 240 C, 1st crack 13min-15 mins, 2nd crack started at 19 mins. Ended at 20 mins.
    Left for 6 days. Probably not a light roast, beans reasonably dark. 95% of beans have no oil on them but a few do. Smells fine as beans.
    Grind: On grinding and before using the grounds are dark and smell OK. But have to use a very fine grind as it gushes.
    The espresso: Using a Silvia and the fine grind and I pack enough in to leave an impression and the puck is dryish afterwards. The used puck afterwards smells rather burnt and the espresso just is too bitter to drink probably as I have to end the pour early.

    So what might be wrong? I can understand that over roast might be burntish but it didnt look overdone. Also why would it gush so fast?

    Mike


  2. #2
    Mal Dimal's Avatar
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    Re: Cyangugu, gushes even at a fine grind & bitter

    Gday Mike,

    The "nominal" grind setting on the grinder doesnt really mean very much unfortunately when trying to compare results with other users. A much more meaningful number, is the number of steps from actual Zero. If you are unsure of what this is, it can be established by following these steps:
    With power OFF, and the Step-Lock depressed, gradually wind down the Hopper/Upper Burr Carrier until you come up against the Lower Burr plate. This is Actual Zero on your particular Rocky. Wind back to the initial setting and take note of the number of steps between this and Zero.

    If you cant wind down to Zero, there may be a travel limiting screw inserted in the Upper Burr Carrier designed to protect the grinder from being set so low as to allow the Burrs to make contact. For the exercise of establishing where Zero is, you can temporarily remove this screw and replace it again after youre finished. Anyway, once you know what your true grind setting is, it will make it a bit easier to gauge what might be going on. All the best,

    Mal.

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    Re: Cyangugu, gushes even at a fine grind & bitter

    Mike,

    as well as Mals advice above..... I suspect you have roasted the beans too far. Most people report good results pulling a roast of this bean at, or just before SC...

    See http://coffeesnobs.com.au/YaBB.pl?num=1173274685/0#0

    I find (with most beans) no longer than 20 Seconds into SC is best - many I dont even take to second crack...

    I think your minute into SC maybe part of the problem..... the beans are tending to be a little burnt..... and with a slower roast this reduces the oils left in the beans (by evaporation / burning off) and so the surface also has less oil.

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    Re: Cyangugu, gushes even at a fine grind & bitter

    Java,

    how important is this oil ? what does it do apart from flavour etc
    when roasting do I want to see oil sooner later or when?
    Im having similar probs with different bean varieties, and also have a rocky now set on 5.

    going to go check it now....

    TIA

    Steve

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    Re: Cyangugu, gushes even at a fine grind & bitter

    Steve,

    Yep, the oil is a significant part of the flavour and is also important in the crema.... From my experience you want to aim for a bean without oil on the surface (or maybe the odd bean with just a small speck) after roasting.... and whilst resting you will get just a little oil on the surface as it seeps out of the beans....

    Some bean varieties can become quite black and shiny with oil when over roasted... especially if roasted fairly quickly whilst others dont seem to have as much oil coming to the surface when taken well into second crack.... and this seems to be more obvious when roasted more slowly....

    I roast with the Corretto (which is an fluid bed roaster - like the popper and Gene.....) most of the roasting is done with hot air.... and my guess is this rapid air movement increases the rate of oil evaporation / burning off of oils compared to a drum roaster... and with long slow roasts this becomes even more noticeable.

    Flavour is certainly different between a drum and a fluid bed roaster because of the way that heat is transferred to the beans.... I dont know if my description above is accurate.... but it is what Ive observed...

  6. #6
    Super Moderator Javaphile's Avatar
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    Re: Cyangugu, gushes even at a fine grind & bitter

    Every bean/roast requires a different grind setting. Ignore what the number is on the index and adjust the grind until your shot times are good and adjust by taste from there.


    Java "Grinding away one cup at a time" phile

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    Senior Member speleomike's Avatar
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    Re: Cyangugu, gushes even at a fine grind & bitter

    Hi
    Thanks for the feedback. I understand that the setting on the grinder is relative, I normally grind at setting 8 for most purchased roasted beans and for my roasted beans 3 is still a gusher. I prob wont worry about the actual number of steps, sees like I over roasted so I will just ditch those beans.

    I still dont follow why if one over roasts the grinds will let more water though? That is what is effectively happening - the impedance to water is far less. Maybe the fibres in the bean material are much shorter or burnt and so dont impede the water as much but I would have thought that grinding would have broken them up anyhow. Unless the fibre size and is so much smaller than the grind?

    Mike

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    Re: Cyangugu, gushes even at a fine grind & bitter

    Very puzzling. I dont think I can really help here, except to pass on a couple of
    observations.

    The last Rwanda I did was just into first snaps of SC (FC around 5:30, finish at
    10:30 in an IRoast). I tried it at day 3 and day 4,
    each time with my usual espresso dose and grind. Each time I got a near-ideal
    30 sec pour with good dark crema. Didnt get to try again as it disappeared
    into my wifes plunger blend for work :(

    I usually get gushers from a roast thats too light rather than too dark. Case in
    point: some Tiger Mountain a couple of weeks ago, accidentally roasted it too light,
    and even after ten days the best I could do was a 20 sec pour with
    one notch finer than usual on my MDF.

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    Re: Cyangugu, gushes even at a fine grind & bitter

    Quote Originally Posted by speleomike link=1179488937/0#6 date=1179545783
    Hi
    I still dont follow why if one over roasts the grinds will let more water though? That is what is effectively happening - the impedance to water is far less. Maybe the fibres in the bean material are much shorter or burnt and so dont impede the water as much but I would have thought that grinding would have broken them up anyhow. Unless the fibre size and is so much smaller than the grind?

    Mike

    Mike,

    I can only assume (i.e. guess) that over roasting with a hot air roaster roaster dries out the beans more.... and just like beans as they age.... there is less oils etc in the bean.... and you have to grind finer and finer as this happens to reduce the water flow.

    Ive got a feeling it is more relevant to hot air (fluid bed roasters)...... large volumes of hot air moving over the bean surface.... (where in a drum roaster there is relatively little air movement...) and air movement causes evaporation....

    can anyone confirm this?

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    Re: Cyangugu, gushes even at a fine grind & bitter

    Interesting theory JavaB. I cant confirm but I just did an experiment.

    We usually have some dark roasted beans on hand to chuck a few into the
    morning latte mixture. I dont usually pull SO shots with them, but I just
    did one to see what happens.

    Used my standard (20.1g) dose and grind setting, which usually gives a
    25-35sec pour. On this dark roast, it came near to stalling the machine --
    60 secs to blonding for about 40ml. Good crema though, and good flavour
    considering the roast level.

    These (Brazil Cerrado) were done on my very simple IRoast "dark profile" --
    max setting (250C) for 15 mins, and stop it about a minute into rolling SC.
    In this case, FC came around 5:20, rolling SC started at 9:10, and I stopped
    it at 10:20/242C. The beans came out very dark, with a sheen, but few visible oil
    spots. After three days, there was some oil visible. Now, at a week, they
    are all showing oil.

    This is the sort of behaviour Im accustomed to with darker roasts.

    However it may well be that if I took the roast to a point where no oil
    came out (as you mention) that behaviour would be different. However
    that has never happened with my iRoast, and Ive now down quite a
    few roasts in the 12 to 14 minute range.

    Will be interesting to see other comments ...

  11. #11
    Senior Member speleomike's Avatar
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    Re: Cyangugu, gushes even at a fine grind & bitter

    Behmor Coffee Roaster
    Hi all

    Thanks for the info on your experiment. So for others a darker roast for a given grind provides more impedance to water through the puck. Yet for me Im sure its the opposite.

    I just tried the Indian Tiger Mountain which I also roatsed last week. It looks a little over roasted; some beans have oil on the surface, they are dark and at my normal grind the coffee gushes like the Cyangugu.
    Tiger Mountain was 100 gm 250C 17.0 mins total.
    (1st C at 10 mins to 12 mins, 2nd C at 15 mins, end at 17 mins.)

    Today I just did my second Tiger.
    200 gm 245C 13.5 mins total.
    (1st C at 10 to 12 mins, 2nd C at 13.5, end at 13.5.)

    and a second Cyangugu:
    200 gm 240C 18.0 mins total
    (1st C at 13 mins, 2nd C at 18 mins, end at 18 mins.)

    Ill let you know how they are next week.

    Mike



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