Results 1 to 22 of 22
Like Tree14Likes
  • 1 Post By greenman
  • 1 Post By Barry O'Speedwagon
  • 1 Post By Barry O'Speedwagon
  • 1 Post By chokkidog
  • 2 Post By Lyrebird
  • 1 Post By Dimal
  • 3 Post By Yelta
  • 2 Post By Lyrebird
  • 2 Post By Barry O'Speedwagon

Thread: Behmor bean vs environment temperature

  1. #1
    Junior Member
    Join Date
    May 2018
    Posts
    8

    Behmor bean vs environment temperature

    Hi,

    Has anyone seen a bean temp and environment temp at the same time? Iím interested to see what happens to the bean temp after first crack if I reduce the power? How closely does it follow the ET.

    Thanks for your help!

  2. #2
    Senior Member greenman's Avatar
    Join Date
    May 2007
    Location
    Perth, Western Australia
    Posts
    3,116
    It would depend on how much heat momentum the bean had acquired, if they did not have enough momentum and you eased off the heat too much they could stall and ruin the roast.
    Barry O'Speedwagon likes this.

  3. #3
    Junior Member
    Join Date
    May 2018
    Posts
    8
    Yeah I wonder what too much is. Staying in p1 auto to 1st crack then hitting p2 manual results in a neg rate of rise (-6 deg/ min) or so for the rest of the roast. Do the beans have enough energy to stay positive or will they drop too..

  4. #4
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    176
    Quote Originally Posted by greenman View Post
    It would depend on how much heat momentum the bean had acquired, if they did not have enough momentum and you eased off the heat too much they could stall and ruin the roast.
    What is "heat momentum"?

  5. #5
    Senior Member Barry O'Speedwagon's Avatar
    Join Date
    Dec 2011
    Location
    PRL
    Posts
    2,452
    Temperature x Mass?

    While obviously not an SI unit, the phenomenon is a function of the external heat being applied and the heat generated by the exothermic reaction that the beans are undergoing. And some other stuff (how many of the beans are left-handed etc)
    chokkidog likes this.

  6. #6
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    176
    Quote Originally Posted by Barry O'Speedwagon View Post
    While obviously not an SI unit, the phenomenon is a function of the external heat being applied ....
    What phenomenon?

  7. #7
    Senior Member Barry O'Speedwagon's Avatar
    Join Date
    Dec 2011
    Location
    PRL
    Posts
    2,452
    Quote Originally Posted by Lyrebird View Post
    What phenomenon?
    Come on, then. I'm sure you're itching to give us the science lesson

    Momentum and / or thermal momentum are commonly used descriptors regarding the roasting process.

    This rather colourful piece decscribes the 'phenomenon'.

    "Like a snowball rolling downhill, the sugar browning reactions develop a momentum of their
    own and the increase in internal energy depends less and less on the heat
    in the environment as the roast progresses and more on the heat already
    taken on, the buildup of pressure within the bean, and the heat released
    by sugar browning. "

    https://www.datocms-assets.com/949/1...s-of-roast-pdf
    Dimal likes this.

  8. #8
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    176
    Yes, it's a common term but I'm not sure what it means and so far haven't found an explanation that makes sense.

    BTW the Songer paper is full of errors so I'd take his conclusions with a grain of salt.
    Last edited by Lyrebird; 3 Weeks Ago at 10:33 AM.

  9. #9
    Senior Member chokkidog's Avatar
    Join Date
    Apr 2008
    Location
    Victoria, Australia
    Posts
    2,056
    Quote Originally Posted by Lyrebird View Post
    Yes, it's a common term but I'm not sure what it means and so far haven't found an explanation that makes sense.

    BTW the Songer paper is full of errors so I'd take his conclusions with a grain of salt.
    Aaaaah crunch. Clickbait. Ok, so I haven't read the Songer paper yet, just clicked on the link and scrolled through it.
    I'll read it later on. In the meantime, and to enlighten us all, perhaps, as it is so 'full of errors', you could point out not what is wrong with it but what is right,
    as that is obviously, to you, the easiest thing to do.

    As to "a common term" are you referring to "phenomenon" or "momentum"?
    Dimal likes this.

  10. #10
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    176
    OK, I think I know why I have everyone off side here.

    As far as I can see "heat momentum" is nonsense. It cannot physically exist and to my way of thinking this means it cannot explain anything. I have a real problem with people using incorrect but "sciency" terms to try to explain things, I think it just hinders any attempt to actually understand what's going on. I understand that that can make me look like an insufferable pedant, but I'll live with it. What I really want is for the discussion to be framed in terms that are comprehensible to all participants and also accord with standard physics but if I have to choose between these I'll take the second every time.

    As for the Songer paper: amongst other things he's misused the term activation energy, it has a specific meaning in reaction chemistry. Moreover, the way he misused it is typical of people who don't understand the basics of reaction kinetics and that means I can't trust that he understands what he is writing about.

    This is not helped by the sentence quoted above, which invokes the idea of temperature momentum, and sentences such as "Since the system has less mass, it is able to take on heat more quickly, but because it is less dense and has lost moisture it can also lose heat more quickly." which is a confusing hodgepodge of terms where a better explanation would be simply that the system's thermal inertia has reduced.

    Then he starts his discussion of the perception of acidity by talking about chlorogenic acid which is a polyphenol and will thus contribute to astringency not perceived acidity.

    Altogether it sounds like he's read a bunch of stuff on this, understood little of it then mashed together an "explanation" which is close to useless.
    Dimal and Yelta like this.

  11. #11
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,024
    Don't hold back Lb, tell us what you really think...

    Mal.
    Yelta likes this.

  12. #12
    Senior Member Yelta's Avatar
    Join Date
    Jun 2009
    Location
    Moonta SA.
    Posts
    5,979
    Quote Originally Posted by Lyrebird View Post
    OK, I think I know why I have everyone off side here.

    As far as I can see "heat momentum" is nonsense. It cannot physically exist and to my way of thinking this means it cannot explain anything. I have a real problem with people using incorrect but "sciency" terms to try to explain things, I think it just hinders any attempt to actually understand what's going on. I understand that that can make me look like an insufferable pedant, but I'll live with it. What I really want is for the discussion to be framed in terms that are comprehensible to all participants and also accord with standard physics but if I have to choose between these I'll take the second every time.

    As for the Songer paper: amongst other things he's misused the term activation energy, it has a specific meaning in reaction chemistry. Moreover, the way he misused it is typical of people who don't understand the basics of reaction kinetics and that means I can't trust that he understands what he is writing about.

    This is not helped by the sentence quoted above, which invokes the idea of temperature momentum, and sentences such as "Since the system has less mass, it is able to take on heat more quickly, but because it is less dense and has lost moisture it can also lose heat more quickly." which is a confusing hodgepodge of terms where a better explanation would be simply that the system's thermal inertia has reduced.

    Then he starts his discussion of the perception of acidity by talking about chlorogenic acid which is a polyphenol and will thus contribute to astringency not perceived acidity.

    Altogether it sounds like he's read a bunch of stuff on this, understood little of it then mashed together an "explanation" which is close to useless.
    I'm trying to translate this into terminology that will better enable me to enjoy my AM/PM cup of coffee!

    Wondering out loud if being able to pronounce - chlorogenic acid and polyphenol - will help with the perceived enjoyment of what is currently residing in my cup, or even if having an understanding of the terms will result in a better brew somewhere down the track, I suspect not.

    It's all about coffee for me.
    Dimal, flynnaus and chippy like this.

  13. #13
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    176
    To each his own.

    I find that it is far more constructive to troubleshoot a process when I understand what is going on within that process.

    You don't need to be able to pronounce chlorogenic acid or polyphenols, but knowing that polyphenols are far less soluble than simple acids like citric helps explain why underextracted shots will tip towards sharpness whilst overextracted shots will tip towards astringency.

    When the product of time x temperature is low, the more soluble components (sugars, simple acids) will dominate. When the product of time x temperature is high, the balance will tip towards the less easily extracted compounds such as polyphenols which often have higher flavour activity per unit concentration.
    Last edited by Lyrebird; 3 Weeks Ago at 09:16 PM.
    Dimal and chippy like this.

  14. #14
    Junior Member
    Join Date
    May 2018
    Posts
    8
    So how much does the bean temp rise at 1st crack if the heat is flat or falling? I’m sure all you experts will know...

  15. #15
    Senior Member Yelta's Avatar
    Join Date
    Jun 2009
    Location
    Moonta SA.
    Posts
    5,979
    Quote Originally Posted by Acmack View Post
    So how much does the bean temp rise at 1st crack if the heat is flat or falling? I’m sure all you experts will know...
    WHAT!

  16. #16
    Junior Member
    Join Date
    May 2018
    Posts
    8
    Quote Originally Posted by Yelta View Post
    WHAT!


    Hi,

    Has anyone seen a bean temp and environment temp at the same time? I’m interested to see what happens to the bean temp after first crack if I reduce the power? How closely does it follow the ET.

    Thanks for your help!

  17. #17
    Senior Member Barry O'Speedwagon's Avatar
    Join Date
    Dec 2011
    Location
    PRL
    Posts
    2,452
    Quote Originally Posted by Lyrebird View Post
    Yes, it's a common term but I'm not sure what it means and so far haven't found an explanation that makes sense.

    BTW the Songer paper is full of errors so I'd take his conclusions with a grain of salt.
    I cited the couple of sentences from that paper (note I described it as 'rather colourful') to give you a quick description of the phenomenon that people were referring to, not as a promotion for the whole paper.

    How often do you roast coffee? In a practical sense, a roaster needs to make a judgement about the optimal time at which to drop the heat being applied. If you do so too early, the roast stalls. If you go too late, not so bad....but the flavour development will be inhibited. Cut the power to 25% 2 minutes before first crack and you'll see what happens.
    greenman and Yelta like this.

  18. #18
    Senior Member Barry O'Speedwagon's Avatar
    Join Date
    Dec 2011
    Location
    PRL
    Posts
    2,452
    Quote Originally Posted by Acmack View Post

    Hi,

    Has anyone seen a bean temp and environment temp at the same time? I’m interested to see what happens to the bean temp after first crack if I reduce the power? How closely does it follow the ET.

    Thanks for your help!

    Have a look at post #12 in the Behmor Max Temps thread (i.e. the one that was on the top of the thread list before you started this one). I think it shows the 2 measures you seek. Otherwise it would make sense to the posters in that thread.

  19. #19
    Junior Member
    Join Date
    May 2018
    Posts
    8
    Quote Originally Posted by Barry O'Speedwagon View Post
    Have a look at post #12 in the Behmor Max Temps thread (i.e. the one that was on the top of the thread list before you started this one). I think it shows the 2 measures you seek. Otherwise it would make sense to the posters in that thread.

    Thank you bos

  20. #20
    Senior Member simonsk8r's Avatar
    Join Date
    Oct 2009
    Location
    Geelong
    Posts
    816
    Quote Originally Posted by Barry O'Speedwagon View Post
    In a practical sense, a roaster needs to make a judgement about the optimal time at which to drop the heat being applied. If you do so too early, the roast stalls. If you go too late, not so bad....but the flavour development will be inhibited. Cut the power to 25% 2 minutes before first crack and you'll see what happens.
    Well said. To me the term heat momentum makes sense, as it sounds like a more practically-minded term. Not meant to refer to the physical momentum mass-based objects retain (so to speak hehe).

    I see it as just how much 'oomph' the beans have to maintain heat when you've dropped heat application. Not overly sciencey hehe but makes sense to me!

  21. #21
    Senior Member Yelta's Avatar
    Join Date
    Jun 2009
    Location
    Moonta SA.
    Posts
    5,979
    Quote Originally Posted by Barry O'Speedwagon View Post
    Cut the power to 25% 2 minutes before first crack and you'll see what happens.
    Something tells me this is one experiment I shouldn't carry out.

  22. #22
    Senior Member simonsk8r's Avatar
    Join Date
    Oct 2009
    Location
    Geelong
    Posts
    816
    Behmor Coffee Roaster
    Quote Originally Posted by Yelta View Post
    Something tells me this is one experiment I shouldn't carry out.
    Haha...

    Once while roasting, the roaster just turned off completely, and I was probably 5 minutes into it.

    So I looked at the beans.... incredibly under roasted. So when the roaster decided to play nicely, I just chucked them back in and continued haha. Was an interesting result ;D

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •