Results 1 to 19 of 19

Thread: Reason for burnt tasting roast

  1. #1
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Reason for burnt tasting roast

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Total novice here , but I set up the Corretto and everything sort of went to plan.

    I used " pcf1978" roasting profile for my first 2 attempts and in my case I generally got to FC in 10.30min and then maintained very slow and steady till SC at 18-19 min .

    http://coffeesnobs.com.au/YaBB.pl?num=1228795908

    This was for MalawiAA and Ethopian Gambella , now both can be drunk , but have burnt undertones for Malawi *, and more so on the Gambella.

    Should I now reduce to time duration between FC & SC ?
    ThunderGod suggested 6 min for this period. Or is my burnt taste coming from some other area of the roast ?

    Cheers
    Greg

  2. #2
    Sleep is overrated Thundergod's Avatar
    Join Date
    Jul 2006
    Location
    Sydney
    Posts
    10,496

    Re: Reason for burnt tasting roast

    From my understanding, the little extra time you take to SC is not a bad thing.
    Burnt to me can mean FC too fast (tipping) or roasted too long; neither of which you appear to have done. :-?

  3. #3
    Senior Member
    Join Date
    Oct 2008
    Posts
    488

    Re: Reason for burnt tasting roast

    Greg,

    Where is your thermocouple placed?

    Cheers,
    Ben

  4. #4
    Senior Member
    Join Date
    Sep 2008
    Posts
    759

    Re: Reason for burnt tasting roast

    Greg,

    Inspect the beans for signs of tipping (slightly darker ends) or divots. By the sounds of it, its unlikely you have either judging on your roast profile, but worth checking for. Also crack open a bean or two from each batch and look for colour changes through the center. They should be even. I find its also good to chomp on a few to get an idea of how the roast went.

    It could also be your brewing method causing the burnt taste. Have you tried cupping them or using a different brew method?

    Also, you dont mention when you roasted them. I did a roast last week, I waited 2-3 days before cupping and using in espresso and pour over. I cursed it all week, then yesterday made the most wonderful latte with it. It just took time to reach its peak.

  5. #5
    Senior Member
    Join Date
    Feb 2009
    Location
    North Rothbury, NSW
    Posts
    1,104

    Re: Reason for burnt tasting roast

    Greg,

    How are you cooling the roast? Is it possible that they are still roasting a touch after you have pulled them?


    Chris

  6. #6
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Re: Reason for burnt tasting roast

    Quote Originally Posted by 545C53555D0702360 link=1245630446/2#2 date=1245632416
    Where is your thermocouple placed?
    Probe is about 20mm off the base of the basket, about 1/3rd paddle ht, well enough buried I think. It reads about 1+ degree out ... ie shows 98/99 in boiling water.

    Quote Originally Posted by 57555951515F5845360 link=1245630446/3#3 date=1245632791
    I find its also good to chomp on a few to get an idea of how the roast went.
    Yep did a chomp test , tasted a bit burnt , though the beans look good, none show tipping. The Gambella roast is a bit uneven, sundried isnt graded as evenly as others.

    Quote Originally Posted by 57555951515F5845360 link=1245630446/3#3 date=1245632791
    Also, you dont mention when you roasted them.
    Gambella roasted on the 15/6, Malawi 17/6

    Quote Originally Posted by 555D454F52360 link=1245630446/4#4 date=1245633944
    How are you cooling the roast? Is it possible that they are still roasting a touch after you have pulled them?
    Cooling via a fan on top of colander and vacuum cleaner /20lt pale method underneth, takes a bit over a minute. SC is still going on when doing the transfer.

    Ill try lowering the temp in VBM Piccolo..... but there is a touch of burnt even when smelling in the valve bag.

    appreciate ya help

    Greg

  7. #7
    Senior Member
    Join Date
    Feb 2009
    Location
    North Rothbury, NSW
    Posts
    1,104

    Re: Reason for burnt tasting roast

    Quote Originally Posted by 5A5D46415A5D56320 link=1245630446/5#5 date=1245638085
    Cooling via a fan on top of colander and vacuum cleaner /20lt pale method underneth, takes a bit over a minute. SC is still going on when doing the transfer.
    Well that blows that theory....

    we will all have to keep looking...

  8. #8
    Senior Member flynnaus's Avatar
    Join Date
    May 2008
    Location
    Sydney
    Posts
    4,116

    Re: Reason for burnt tasting roast

    Pardon my ignorance with roasting but if it tastes burnt, isnt it just that it was roasted too long?

    I have only done a few roasts in a popper. My second roast was stopped at rolling SC - probably CS10.5 or 11 -and it tasted burnt.

    If it tasted burnt when you chewed a bean I dont think you need to adjust the brew temp

  9. #9
    Senior Member
    Join Date
    Feb 2008
    Posts
    1,339

    Re: Reason for burnt tasting roast

    Hi Greg

    I need to say at the outset that I have never been a corretto user, so take the following for what its worth, and your responses may provide those more familiar with the method to take more than a stab in the dark...

    Can you tell us the weight of the beans that went in?
    This info may help determine if youve either under or over loaded.

    Can you tell us the weight of the beans that came out?
    I have a sneaking suspicion that your time between first and second crack is too long.

    While breaking apart a few beans to check the internal colour is all well and good, I find its best if you do this in good, natural lighting. Youll get an even better perspective if you can grind some of the coffee (turkish), tamp it down in a petrie dish or similar, and then do your comparison.

    Of course, photos cant hurt to obtain some advice either.

    All the best!






  10. #10
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Re: Reason for burnt tasting roast

    Please be aware , last week I was the "Virgin *roaster" .... using a CS starter pak

    Quote Originally Posted by 495F5A5A4B49454C4C4F4F2A0 link=1245630446/8#8 date=1245640562
    Can you tell us the weight of the beans that went in?
    250g green bean *produce 219g brown

    I appreciate my results maybe better if I do larger roasts but as a novice you dont want to stuff large ammounts so I split the 500g CS pak in two .

    photos coming soon .....

    cheers

    pic1 Gambella *roasted 15/6
    pic 2 malawi *roasted 17/6
    these pics were taken on different days different light conditions





  11. #11
    Senior Member
    Join Date
    Feb 2008
    Posts
    1,339

    Re: Reason for burnt tasting roast

    Ok, so the weight loss is probably in the ball park.

    But...Im pretty sure the amount youre roasting is playing a significant part in the outcome. *

    Again, no experience with the corretto, but for optimum results with any roaster, you need to charge it with the optimum amount of beans. *250gm is probably around half the ideal batch size, so at the very least, you would have to modify the process. *The difficulty therein is that half the batch size doesnt equate to halving everything you do, ie. temp and time. *Its a more logarithmical change thats required.

    If the lighting conditions are the same in both pics, the Gambellas look fine but the Malawi does look to be burnt.

    Mal is usually here in the evening, so will be interested to hear what he has to say. *Hell be able to provide far better advice, but for the time being, hope Ive helped a little.

    EDIT: Oh, and stuffing it up is a good thing. At least now you know where not to go, and besides, I thought home roasting was cheap and fun!




  12. #12
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,968

    Re: Reason for burnt tasting roast

    Gday hotshod... :)

    I reckon Dennis has got it pretty well nailed. I never exceed 5:00-5:30 minutes between the end of Rolling First Crack(RFC) and the start of regular snaps of Second Crack(SC). I think you can definitely overdo the gradient reduction to a point that by the time SC does come along (if it does get there) the beans start to adopt that yucky baked/bitter-ish edge. Just from tasting the results of experiments with my particular Corretto setup, Ive found I get a much more pleasing outcome in the cup, if I keep the EndRFC > StartSC gradient to a median of around 4C/Minute. Thats me though with my setup, no guarantees that this will be ideal for your particular setup and your palate.

    Correttos do indeed have an "ideal" batch size range too, probably like any other roaster for that matter. In mine and using a 2,000W Ryobi Heatgun, it lies somewhere between 600-800g. These days, I pretty well stick to 750g batches so as to reduce the variables down to a manageable level. Continually changing batch sizes introduces all sorts of difficulties that my humble Corretto and its owner/operator would rather not have to face.

    If you roast at under the ideal batch size, all sorts of things become exaggerated and difficult to manage, e.g. a less than ideal bean agitation which results in uneven roasting of a significant percentage of the batch, heat input adjustments are much more sensitive too unless you have access to a variable output heatgun to compensate for the smaller batch size - Simply raising and lowering a fixed output heatgun in this situation is very finicky.

    On the other side of the coin... Batches that are too large result in a different agitation problem, since the beans arent being circulated through the overall mass very efficiently, you can end up with dead spots in the batch that result in a large number of beans that dont circulate much at all and either become roasted too quickly or that dont roast quickly enough, depending on where the dead spots are in relation to the heat source....
    The other significant problem though, is that your heat source may be insufficient for the physical mass of beans involved resulting in extended roast times or very poor control over segments of the roasting cycle. This can result in batches that are baked instead of roasted or simply batches that have not been optimised because too little control over the heat input leads to a situation where you need to maximise the heat output of the heat source throughout the entire roast in order to complete it at all. This leads to additional problems that could result in a percentage of the batch becoming burnt on the outside of the bean but under-roasted on the inside.
    So, as you can see, venturing outside the ideal batch size for a particular Corretto setup can cause all sorts of problems that may seem nonsensical when compared to the results you observe in the cup.

    And yes Den... Roasting at home is lots of fun and if cheap is important, then it can be cheap too... ;D ;D

    Mal.

  13. #13
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Re: Reason for burnt tasting roast

    Thanks for your input Denis & Mal....

    Ill try and post better more consistant photos.
    My BM is the 1kg loaf Breville, Im gradually increasing roast size.

    I knocked out 2 roasts today , one was 320g Peru Cedja de Selvia ...... SC about 5min after FC, smells good , though quite dark, might have pulled it a bit early.... Likewise the other was the remaining 250g Gambella..... 219c SC ,5.30 min after FC.
    I deliberately tried to speed up between FC & SC .... was aiming for 6 min , but pulled both at first sign of SC, maybe 10 to 15 secs into it, and continued into the cooling phase.

    Im still using a 70mm heat spreader extension on my heat gun , mostly so I can get the end closer to the BM basket.

    Tomorrow I intend to do a 400g Mexican Decaff , that came from DiBella...... Will try and follow " WSully" decaff roast profile ,.... though it does sound like the temp is a bit low....

    http://coffeesnobs.com.au/YaBB.pl?num=1244175090

    Any input or directions will be appreciated

    Cheers
    Greg ....or
    Bono.....or
    hotshod....

  14. #14
    Sleep is overrated Thundergod's Avatar
    Join Date
    Jul 2006
    Location
    Sydney
    Posts
    10,496

    Re: Reason for burnt tasting roast

    Those are small batch sizes for a 1kg BM.

    I have a standard size BM and do 600g batches.
    As Mal said, 300g are finicky (though I did start that small) and 700g also has its problems and is the physical limit for the amount of beans it will hold once roasted.

  15. #15
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Re: Reason for burnt tasting roast

    Yeah thanks TG

    Lifted the batch size up to 400g..... and as a green bean sitting in a stationary BM , that leaves about 5mm of the BM paddle just showing.

    Am I getting close ...?????

    cheers
    greg

  16. #16
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,968

    Re: Reason for burnt tasting roast

    Quote Originally Posted by 7C7B60677C7B70140 link=1245630446/14#14 date=1245805290
    Am I getting close ...?????

    cheers
    greg
    Nope.... ;D

    60% of 1.0Kg is 600g and that is where Id be starting.... ;)

    Mal.

  17. #17
    Senior Member
    Join Date
    May 2008
    Posts
    437

    Re: Reason for burnt tasting roast

    Definitely lift the batch size. I have a 750g Remington and cant really go much below 400g or it can be liable to over-roasting, and at 600g it struggles with turnover. With 400g I cover the top of the paddle - thats about 1/3rd full.

    Great info up there ^ from experienced people.

    When I start with a new bean, I deliberately take the first roast to RSC so I know where it is, immediately do another batch (or two) and back off either at SC or just before and experiment from there.

  18. #18
    Senior Member
    Join Date
    Nov 2006
    Posts
    1,077

    Re: Reason for burnt tasting roast

    I always have the top of the paddle covered, dont know by how much, never really looked at it before but i now do batches of 600gm and get really consistent looking results.

  19. #19
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Re: Reason for burnt tasting roast

    Behmor Coffee Roaster
    Thanks guys ....

    I guess you know how it is when you first start , being a bit cautious...... If Im going to stuff up let it only be a small ammount.

    Done at least 4 roasts now , getting a good feel for adjusting the HG , and consistantly hiting the prescribed min/temp marks..... plus being organised at the end of the roast when all the madness starts... :o

    Good fun

    Thanks for all ya help ....... soon to be a roastaholic or a roasting snobber

    cheers
    Greg



Similar Threads

  1. Gaggia Dandy burnt tasting coffee
    By oneaday in forum Brewing Equipment - Midrange ($500-$1500)
    Replies: 15
    Last Post: 31st December 2011, 10:00 AM
  2. First Roast - burnt?
    By pusca in forum Home Roasting - Tips, Tricks, Ideas
    Replies: 10
    Last Post: 17th July 2010, 12:21 PM
  3. Burnt/grass/green roast, what to do?!?
    By Iconiq in forum Home Roasting - Tips, Tricks, Ideas
    Replies: 8
    Last Post: 9th September 2008, 08:56 PM

Posting Permissions

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