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Thread: did I stall this roast?

  1. #1
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    did I stall this roast?

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    I did my first hottop roast today with 250g of Brazillian Daterra that came with the roaster.
    I tried to follow the chart greg put together but had to make adjustments as I was rampimg too fast at the start.

    FC was very quiet. When SC started I am not sure if it was just FC continuing. It only finished at cs8-9. I was aiming for dropping at RSC but I am not sure if I got there or if I stalled it. What do you guys think?


    Minut Temp * * Heat % Fan % Event
    0 75 100 0
    1 85 100 0
    2 101 100 0
    3 118 100 0
    4 135 100 50
    5 150 50 50
    6 163 50 50
    7 170 50 50
    8 176 50 50
    9 179 50 50
    10 181 70 50
    11 183 70 75 FC start 11:00
    12 185 70 75 RFC 12:30
    13 189 40 100
    14 191 40 100
    15 193 40 100 sc start 15:30 ? Maybe still FC
    16 196 40 100 maybe RSC 16:40
    17 197 40 100
    18 198 40 100
    19 198 40 100 pulled 19:31 /198c


  2. #2
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    Re: did I stall this roast?

    Sink cut,

    Yep, Id say reducing the heat to 50% was too much - too soon to start with.

    You will find that it might ramp a bit quicker initially (depends a bit on your mains voltage) but that isnt of significant concern...... you need to get into FC and RFC with a fair amount of heater power..... 50% wouldnt be enough. At about 70% and less the ramp seems less dependent on the mains voltage..... so if you had reduced to 70% the rate of increase would have been similar to the one provided.

    Id say you were hearing mainly FC..... you normally wont get into SC until about 203 on the display (which by the way is actually about 213-215C if you have a bean mass temperature probe....

    You need to be a little more aggressive!

  3. #3
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    Re: did I stall this roast?

    Thanks Robin,

    The reason I dropped to 50 is because thats where gregs routiene drops to 70 - and my roast was ramping a lot faster. Ill try again leaving a bit more power on even if there is a steeper initial ramp.

    thanks

  4. #4
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    Re: did I stall this roast?

    and robin, Thanks again for sending the HT, I am very happy with it so far - It looks like a serious piece of equipment.


    dAvid

  5. #5
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    Re: did I stall this roast?

    Yep,

    The sample you were supplied followed the indicated profile.... and I have 250V here!!!

    Just reduce the heater power when you get to the defined temperature points (pretty much ignore the time - that will vary depending on your mains voltage, ambient temperature, the actual heater power (not all elements are exactly the same).... the quantity of beans etc).....

    So when you get to say 140C at 15 minutes 30 seconds (instead of 15) just reduce the heater power to 70% at that time. There is some lag before the change in rate becomes apparent (lots of metal in a HT).... but it will happen..... and if you do that at each temperature set point..... you should end up with a roast exactly as supplied as the test roast!

    All roasts are checked using a bean mass temperature probe by the way.... so I know each and every roaster will follow the desired profile using those settings.... some might just be a minute faster overall.

  6. #6
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    Re: did I stall this roast?

    Thanks

    If I save the roast profile does it remember the time I changed the heat and fan? or does it remember the temperatures at which I made the changes?
    david

  7. #7
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    Re: did I stall this roast?

    David,

    It remembers the time..... not as ideal as temperature..... but Ive found for a given roaster that is quite reliable.... but from roaster to roaster..... it doesnt work as well as there is a bit of difference from one roaster to the next.

    And when running from a saved profile you can make changes (e.g. as the weather warms up.... you will need to reduce heater power a little earlier....) and when finished the roast you can save the changes for next time.

    I believe it is a really good idea to make manual changes in any case (using the saved profile as a base)..... the best roasts are those where the roaster (the person doing the roasting that is!) controls the process!

  8. #8
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    Re: did I stall this roast?

    Gday David & JB,
    Thanks David for asking the Question. JavaB I was wondering if there is anyway to find out what the saved profiles were on a new machine. Im at a similar stage to David. I havent saved any myself so I was wondering if you saved the test roasts on new machines?

    The Hottop does a terrific job, I just need more practice with it. * ;)

    Thomas

  9. #9
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    Re: did I stall this roast?

    Thomas,

    On the P model there will be a program called "TST" - which is the one I used during testing (how the supplied beans were roasted.....) on some of the earlier B models there is also a program stored - generally in the first address location.

    Because the voltage over here in WA is much higher, the profiles stored on the B would most likely be of little if any use to others (the heater power would be reduced too early) - so they are no longer being stored (just follow the set points on the tips sheet).... but the P profiles will still be there. There is also a "profile" stored in the P which appears to be the same as the AUTO profile..... but that is how it comes.... and I cant see any real use for it.

    And practice makes perfect..... and once sorted the HT does a great job for sure.

  10. #10
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    Re: did I stall this roast?

    David, I may as well post my reply to your email in here to maybe get a handle of its accuracy from those with more knowledge than I have, and even to possibly help some others with less:

    Wow looks a bit different to mine. I think I know what might be going on, but cant be sure, Ill tell you my experience.

    My first couple of roasts, I thought basically the same thing: FC is very quiet and long and not sure if I hit SC. After a few more I noticed that I can always hear FC and SC - I guarantee once youve heard them you wont miss either of them again. I always got to the point where the beans were getting lighter (weight, not colour) and made more of a rattly sound in the drum and I mistook this for FC a couple of times, and was always thinking it was starting and was never really sure. Ill say FC starts on the first crack I hear, its a loud definitive crack, and often comes not long after I hear the first whoosh of a piece of chaff hitting the element and combusting (which is another thing Ive mistaken for FC). RFC is pretty much when I hear 2 or 3 cracks near each other, I rarely get more than about 5-10 cracks from FC over a minute or two. On my roaster FC normally comes in when the gauge is reading close to 200.

    Second Crack is a lot more frequent, and (it took me a few roasts to realise) very obvious over the rattling of the beans in the drum, it normally happens somewhere between 205-210, and is slighter quieter from FC, but easily distinguishable as it is significantly higher pitched (there is a description in either the manual or Gregs notes which is perfect, FC is like snapping pencils, and SC is like snapping toothpicks).

    The Daterra in my experience has a very sparse FC, as do most beans I think, but the Daterra I really noticed this with, only getting about 5 cracks out of first each time.

    With my latest experimentation, I start at 100% heat, and turn on fan1 at about 105C. (I counter the fan3 the auto profile gives, as well as when it drops the heat back to 80% soon after). When the readout is 185 I put it up to fan3 and heater 0, until the temperature gradient drops significantly (to about 1deg every 20s) then, leaving the fan at 3, crank the heater to 50%. This normally sees me hitting FC at about 15min, rolling about 1min after, and coasting through to SC at a 1-2deg/min gradient, getting the first clicks at about 20-21min, and rolling soon after at which point I normally eject. Beans are about CS9-10.

    I originally was trying to get my FC down at 11-12min but with the temp gradient at 1-2deg/min by the time it hits. I havent done this successfully yet. This, together with me never going past SC but consistently getting CS9-10 (as opposed to your 8-9), as well as the fact that I normally see FC in the high 190s - leads me to suspect that you could have mistakenly thought something else was FC, and your suspected SC was actually FC, and you never reached SC.

    Just a guess anyway - let me know how the next batch goes. I often nearly stall the roast around FC trying to get the gradient nice and low, I havent perfected the roast techique I outlined above, and usually make little adjustments outside of what I wrote based on what the temp is doing. I havent written up any tables yet, and should probably really start I had a laugh. Ill write out a proper profile sheet next roast and send it to you.

    Cheers

    Sam

  11. #11
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    Re: did I stall this roast?

    Thanks JB,
    I dont know about once sorted? Ours did great out of the box until I wasnt in the room to "Push Buttons" and Meaghan hasnt read the instructions (only blokes get in trouble for not doing this). It beeped for 180 C and Meaghan didnt push a button to continue the roast, so it dumped the beans and she finished them off in the wok.
    After this I was allowed to do all those "Snobby" things and try a near manual roast following your instructions. Im still resting them till I can compare the results but they look and smell great.
    I am now re-reading everything to let it sink in properly to try and improve the practice.

    Thanks for the help,

    Thomas

  12. #12
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    Re: did I stall this roast?

    Thanks Sammus and JB. My second attempt is below. Stalled it at 198 but still got to 203 in the end. The roasted beans look way better than the first roast, they are a lot bigger, a bit darker and more evenly coloured.

    Ill keep trying....

    Minute Temp Heat % Fan % Event
    0 75 100 0
    1 88 100 0
    2 106 100 0
    3 124 100 0
    4 141 70 25 4:16 /142 fan and heat
    5 154 70 50 5:45 /162 fan
    6 164 70 50
    7 172 70 50
    8 178 70 75 8:37 /180 fan
    9 183 70 75
    10 187 70 75
    11 190 40 100 11:10/191 fan heat
    12 193 40 100 fc start 12:12
    13 195 40 100 RFC 13:05
    14 197 40 100
    15 198 40 100
    16 198 40 75 16:20/198 *fan
    17 197 40 75
    18 197 60 50 18:37/197 fan and heat
    19 196 60 50
    20 197 60 50
    21 198 40 100 sc and fan adjust at 21:30/201
    22 201 40 100 dropped at RSC 22:28/203
    23 203

  13. #13
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    Re: did I stall this roast?

    David,

    Looks like you could use 50% at 190.... until say 198...... then drop to 40% (post FC the roast is giving off heat and so you need to add less to continue the slow ramp up.....)

    Sometimes I also increase from 40% to 50% right at the end to bring on SC.

  14. #14
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    Re: did I stall this roast?

    Hi David,

    Dont worry too much if you stall the first few roasts in the B. I had exactly the same experience initially and reverted to the P controller for a while, but of course back then I didnt have any help on what power levels to use, it was purely running blind! It can take a little while to learn what changes you need to make to effect the desired change in the drum. The most common mistake is to panic and change settings before your last change has completely taken effect. Yours certainly runs hotter on 100% than mine; I dont get much more than about 14deg/min climb early on whereas yours is in the high-teens.

    Looking through some of my old roasting logs, for a while I was dropping the heater power to 40% at the same time I put the fan to 3, i.e. around the 180 degree mark. This may seem retrograde in your situation but this allows a few minutes for the temperature rise to start slowing down, so once you get the temperature spike around FC you dont already have a 3-4 degree / minute ramp which gets turned into a 6 degree/min ramp. At this point the fan goes up to 4 to moderate the spike and you continue down to about a 2 then 1 degree / min ramp to SC with the roast finishing around the 19 minute mark. However as we say in the Tips and Tricks information, all those settings are approximate and may need tweaking for your unit, so as JB says you may need to make that 50% instead of 40%.

    So maybe try dropping heater power from 70% to 50% and turn the fan to 3 around 180, and then fan to 4 around 192ish (round FC), then drop the heater power to 40% in the high 190s. Monitor the end of the roast because theres that much heat floating around that 10% could make quite a difference in how it behaves. You may need 30% for example rather than 40%.

    Good luck!

    Greg

  15. #15
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    Re: did I stall this roast?

    Hi Sink Cut
    Like you, I found my first roast temps ramping up a lot quicker than the sample profile provided but I stuck to the changes in heat and fan settings based on the suggested temps and had a pretty good result on for my first attempt.
    For some reason (I did change power outlets) the second roast almost stalled and so I had to experiment with different settings for the next couple of roasts to try and achieve consistently smooth profiles. I now drop the heat to only 50% when the fan is increased to !00% and then monitor how much the temp increase is slowing. Sometimes I finish the roast on 50% heat and sometimes I need to drop the heat to 40% a couple of mins. later.
    I also found that my temps at FC & SC were about 4-6 deg higher than the sample roast so I also factor that in when changing settings ie. I wait until my temps are 4-6 deg hotter (depending on timing) before I change settings.
    Ive completed 12 roasts now and am achieving the consistency I wanted.
    I have charted all of my roasts. PM me if your interested in viewing my learning curve and I will email you the spreadsheet
    Good luck with your roasting. With a bit of trial and error youll master that roaster in no time at all. ;)

    Mal

  16. #16
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    Re: did I stall this roast?

    Thanks for all your help guys. I am at it again tonight, this time with different beans as I have run out of brazilians.

    As for the roasts I have listed above, the first (stalled badly)one has good aroma but is undrinkable as espresso because it is SOUR (I have only had coffee this sour before from amanti)

    The second roast (stalled but still made it) has an initial sweet flavour, fairly thin body and a slightly bitter end. Not really bad but not really good... its only just 24hrs old though so I am sure it will change.

    Thanks

    David

  17. #17
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    Re: did I stall this roast?

    Behmor Coffee Roaster
    Hi David,

    Ive found the Brazil really needs to rest for a good 2-3 days otherwise it ends up tasting more like a Kenyan (to my palate anyway). All other things being equal, youll be surprised at the difference after 7 days.

    I went back through my roasting log last night (for those not keeping a roasting log, start now! Times like this its invaluable) and found that up until the end of June I was dropping the power around 180. I then experimented with leaving this until around FC and initially it worked quite well, but more recently Ive found the roast runs away from me towards the end. So I did 300g of Decaf Mocha Java last night where I dropped the power earlier to help a more gentle end to the roast. Note that this is for 300g of greens and for a 250g roast Id be using 70% and 40% respectively (your settings may need to be different). Also Ive made the changes here on the whole minute intervals that are as close as possible to the 140/165/180/192 points I normally use.

    Time Temp Adjustments
    20 75
    19 75
    18 89
    17 106
    16 122
    15 138 80%, fan 1
    14 150
    13 159
    12 168 fan 2
    11 175
    10 181 50%, fan 3
    9 185
    8 190
    7 193 fan 4
    6 196
    5 198
    4 200
    3 201
    2 203
    1 204 roast stopped

    In hindsight Id probably have been better to turn the fan to 4 at the 8 minute mark to allow it a 1 deg/min ending. I guess a bit more experimentation will help nail down the best combo for my setup (and you for yours). Anyway it looked like this:




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