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Thread: rolling first and second crack became one?

  1. #1
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    rolling first and second crack became one?

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    I had an interesting roast today. *I modified my oven to try and increase the time from first crack to second crack, which i thought was dragging on a bit too much before. *The result is shown in the plot below. *

    All was going nicely with the mexican organic from beanbay. *When the beans were added to the oven, the temp only dropped to 90 degrees, as I didnt quite mount the thermocouple low enough (it was just covered at the beginning, but well covered later). *It hit first crack at 9.8m, or 190 degrees, and rolling first crack at 13m, or 213 degrees. *These temps were similar to my other roasts of this bean. *But this time, when I got to rolling first crack the temp went crazy. *It shot right up, and even with some additional venting added when i saw it going up too much, it just kept going. *rolling first crack seemed to drag on and on - *and eventually it clicked that I must have moved into rolling second crack also, as the beans were about CS10/11.So i dumped them. *Does this sound right that I could have moved straight from rolling first to second crack?

    Im thinking that I will need to approach rolling first crack slower in future to stop this happening? *Or does this more relate to the size of the the batch being roasted (by the way, was 550gms)?






  2. #2
    CoffeeSnobs Owner Andy's Avatar
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    Re: RFC and RSC became one?


    Ill provide some clues if you stop using TLAs.
    **shudder**

    While we can workout what RFC and RSC stand for it makes the site a horror for a newbie.

    ;)

  3. #3
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    Re: RFC and RSC became one?

    Sure, not a problem! (now that I have googled TLA!).

    Some clues would be great.

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    Senior Member speleomike's Avatar
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    Re: RFC and RSC became one?

    Hi all

    RFC has always stood for "Request for Comments" (see http://www.ietf.org/rfc.html and http://en.wikipedia.org/wiki/Request_for_Comments) which define most of the protocols that we use in todays computer world. For instance email is defined in RFC 2822 - Internet Message Format, the DNS system that we use to look up any internet site like coffeesnobs.com.au is defined in RFC 1034 & 1035 and so on for ftp, http etc for hundreds of RFCs. Even Ethics and the Internet is covered by RFC 1087.

    Oops, sorry your talking about Rolling FC. I hadnt realised.
    Sorry I have abused RFC 1087 that states
    "... unethical and unacceptable any activity which purposely:
    (c) wastes resources (people, capacity, computer) ..."

    :-)

    Mike

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    CoffeeSnobs Owner Andy's Avatar
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    Re: rolling first and second crack became one?


    DNS Mike? ;-)
    Yes, I did the request for comment = RFC initialy too, 18 years on the net (errr back when .AU was .OZ and we read RFCs) will do that to a guy.

    Sure, not a problem! (now that I have googled TLA!).
    Ha ha! Justice for the newbies... thats what they have to do when they read your post too.
    :)

    Where was I before I abused RFC 1087....

    It looks and sounds like your roast went exothermic (normal) but had enough mass to get away. Half a kilo of beans store a heck of a lot of heat and just after 1st crack they will start to create their own additional internal heat too.

    The sharp spikes in your graph are a perfect example of "roast off the rails".

    At first crack you can remove nearly all the heat (nearly all!) and just have them gain at 3-5 degrees per minute. The rest of your profile looks great, just flatten that steep bit at the end and you should have a 1st crack, rolling 1st, a short pause and then think about dropping them into the cooler as you hear the first cracks of second.

    You are getting closer.

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    Re: rolling first and second crack became one?

    ok, Thanks. I will ease it off once I get to first crack. That will probably just mean sliding the lid off by a cm or so to let some heat exit.

    The other thing I am thinking is that I will try and improve the agitation to see if more agitation helps disperse the heat. Or is this not going to do anything to help?

  7. #7
    CoffeeSnobs Owner Andy's Avatar
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    Re: rolling first and second crack became one?


    I dont know your setup and certainly dont know the variables... this is where YOU come in, try different things until you are happy with your output (we can offer support and a little guidance along the way).

    ;)

    Applying the same heat after 1st crack as you applied leading-up to it will often result in a overly rapid "1st, 2nd, oops char" roast.

    ...which you may or may not like!

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    Re: rolling first and second crack became one?

    yep lots of experimenting needed. There are so many things to try, but only so much I can drink!

    Ill be giving my "1st, 2nd, oops char" roast I a test out soon. Once I have made it through my "1st, waiting, waiting, waiting, 2nd" roast.

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    Re: rolling first and second crack became one?

    Progress report!

    I did another 2 roasts today. Both approaching 1st crack very slowly. Both got away from me.

    I am now thinking the problem I have is that the 550 gms is in a quite compact space (ie, not spread thinly over a larger base). I think this means when the beans give off heat, there is too much surrounding beans to allow the heat to escape. I will try increasing my agitation next to see if this helps disperse the heat. If this doesnt work, I will try smaller batches. If this does not work, I will try a flatter, larger roasting pan.

  10. #10
    CoffeeSnobs Owner Andy's Avatar
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    Re: rolling first and second crack became one?


    Yep, lots of things you can try.
    Change just one thing each time and you will know which one fixed it!

    ...and importantly, have fun learning along the way.


  11. #11
    Wine_of_the_Bean
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    Re: rolling first and second crack became one?

    If your roasting chamber is really good at holding in heat, cutting the heat around first crack will probably do the trick.

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    Re: rolling first and second crack became one?

    Hi Andy - yes im sure it will be a fun learning experience. *Ive already seen a few interesting things happening to my beans. *Ive had some with divots (I think that is what they are referred to as, the little circles blown off the bean), and I have also had something where one side of the inner bean breaks off. *Im assuming it is my heat problem causing both.

    Hi Nunu, I tried really taking the heat out as much as I could before I thought I would go backwards. *I really think now that the beans are sitting too together, and either need more agitation, less beans, or more spread. *

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    Re: rolling first and second crack became one?

    Behmor Coffee Roaster
    Quote Originally Posted by Andy Freeman link=1219664767/0#4 date=1219668234
    *Half a kilo of beans store a heck of a lot of heat and just after 1st crack they will start to create their own additional internal heat too. *

    At first crack you can remove nearly all the heat (nearly all!) and just have them gain at 3-5 degrees per minute. *

    Well there you go... I thought i was going crazy! So the beans do release heat themselves at first crack! I can take the heat gun away and have it gain 4 degrees (although i figured out that after 2, you need to re apply so it doesnt drop... if you reapply after it peaks itll drop about 5 degrees!)

    I was just browsing to see if this was a normal thing and what do you know :)



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