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CharcoalRoaster
11/04/2019 1:58 AM
+1 snwcmpr

snwcmpr
11/03/2019 2:16 AM
Can we make the shoutbox UNAVAILABLE until a member has a certain number of posts?

allenb
11/01/2019 2:20 AM
Funopt, please post in the gas and electric heat sources forum

Funopt
10/30/2019 5:17 AM
Can someone help me for using forced propane burner as my heating element. I rather want to use lpg than electric. Do you think it would work

snwcmpr
10/22/2019 5:31 AM
Thanks to you all....... I was not sleeping ... I stayed awake worried about it all. :)

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90% of my roasts, even light City roasts, have an underlying burnt/acrid taste. What gives?!
primarist
Basically what the title says. I'm starting to get a bit frustrated as nearly all of my roasts have this astringent/acrid bitterness underneath all the other origin flavors; sometimes it can be very overpowering. Even my lightest, just-past-FC roasts still taste burnt. Here is an example of my most recent roast:

Roaster: Kaldi Fortis w/ Center 301 thermometer
Coffee: Washed Honduras San Salvador
Weight: 400 grams

Charge Temp: 400°f (BT)
Drying End: 5:12 (320°f)
First Crack Start: 7:45 (365°f)
First Crack End: 9:38 (385°f)
Drop: 11:35 (400°f)

Basically... how is this possible? The profile and beans appearance suggest a lovely medium-light roast. Instead it tastes like drinking battery flavored charcoal. Obviously this is part of the learning process, any ideas? Thanks!
 
Koffee Kosmo
Firstly - Do you allow the beans to degas
Second - What is your brew method e.g espresso machine, pour over, drip

In general I believe that your first crack is to early - try for 9 to 12 minutes to first crack
I also believe that your beans are roasting faster on the outside and slower on the inside

However in my experience ( over 2500 roasts ) a light roast is best at least 3 min past first crack
A burnt flavour can also be from water that is to hot - freshly boiled water should be allowed to rest a couple of minutes before pouring

KK
I home roast and I like it
Blog - http://koffeekosm...gspot.com/
Bezzera Strega: Mazzer Robur Grinder: 5 Box hand grinders: Pullman Tamper Convex: (KKTO) Turbo Oven Home Roaster: CONA Glass Rod Syphon: Pyrex Brewer:
 
http://koffeekosmo.com.au
primarist
1. Yes, these beans have been sitting for about five days now

2. The first thing I tried troubleshooting was actually my brew method, as I figured I was overextracting! However, I believe my brewing method is okay? I have tried using both my Bonavita drip machine and my Aeropress. For a grinder, I'm using the 1zpresso JX with a moderate grind. Here is my usual Aeropress recipe that works for 90% of the coffee I buy:

18 grams of coffee (sea salt consistency)
200 grams of water (30 seconds off boil, ~200°f)
Rinse filter
Steep for 1:15
Press for 0:15
Total brew time of 1:30

Worried that I was overextracting, I tried progressively lowering the amount of ground coffee while keeping the other variables constant. Same flavors, just a weaker cup! Anyways.. do you think that it might be helpful to, instead of brewing a cup to evaluate my roast, I actually tried cupping it? Since cupping is a simpler process with less variables, maybe I'd get a more consistent read?

Thanks a ton for all the help! The process is so mysterious right now so its good to hear from someone with more experience.
 
Jakuka
I roast light to medium light almost exclusively. And I'm with Koffee Kosmo in that my best roasts are developed a tad slower than that. However, assuming your thermocouple is accurate, I'm not sure it's the roast here that may be giving you the "battery" flavors you're describing. I'm gonna throw you a curve and suggest you may actually be under extracting the coffee rather than over extracting it.

It sounds backwards, I know! But it's actually not uncommon for many people (including myself) to ascribe astringent and bitter as flavors for under extracted coffee. Under and over extractions can both taste bitter to me....but each has a completely different type of bitterness. A sea salt grind is pretty course for an aero press, especially in a light roast. Try grinding finer, a lot finer....say in the fine to medium fine range. Or alternitively you could steep it a lot longer. But provided your grinder is capable I'd opt for grinding finer first as you may be able to pull out a few more subtle flavor nuances of the bean origin than what a coarser grind will sometimes allow.
 
primarist
I'll give it a shot (no pun intended) when I get home! It would be very weird to me since I brew a wide variety of coffees with this recipe and always get awesome results... Why would this one specific coffee break the trend? Anyways, I'll report back in a few hours with the results. Thanks!
Roaster: Kaldi Fortis
Grinder: 1zpresso JX / Baratza Encore
Brew Method: Aeropress / Bonavita Drip

I love coffee, but roast a lot of charcoal
 
allenb
Basically what the title says. I'm starting to get a bit frustrated as nearly all of my roasts have this astringent/acrid bitterness underneath all the other origin flavors;



Why would this one specific coffee break the trend? Anyways, I'll report back in a few hours with the results. Thanks!


It's probably the way you wrote it up but seems to contradict. All of my roasts versus this one specific coffee?

Charge Temp: 400°f (BT)
Drying End: 5:12 (320°f)
First Crack Start: 7:45 (365°f)
First Crack End: 9:38 (385°f)
Drop: 11:35 (400°f)


My own personal observations with my roasts is anything under 4 min for drying end to first crack start, except for those rare 5% killer, roast themselves greens that shine regardless how we mistreat them will come out with various taints in the cup.

18 grams of coffee (sea salt consistency)
200 grams of water (30 seconds off boil, ~200°f)
Rinse filter
Steep for 1:15
Press for 0:15
Total brew time of 1:30


I have very rarely gotten a complete panorama of notes from any coffee with less than 3 1/2 minutes steep time at proper brew temp and this at medium to medium-fine grind. From time to time, I do a large french press with double recommended dose at sea salt + grind size at a 4 minute steep and gives very nice, smooth results but with only certain coffees. Others come out lacking detail and with naturally acidic Kenyas, can be tounge piercing.

My suggestion would be to stick with the SCAA brewing best practice guidelines for all coffees and brew outside of those parameters for comparison.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
primarist
It's probably the way you wrote it up but seems to contradict. All of my roasts versus this one specific coffee?


Oh sorry, I didn't make that very clear. I was saying that this brew methods works very well for all the other beans I've purchased from other pro coffee roasters!

My own personal observations with my roasts is anything under 4 min for drying end to first crack start, except for those rare 5% killer, roast themselves greens that shine regardless how we mistreat them will come out with various taints in the cup.


Great advice, I've been shooting for 4 minutes drop-drying and 4 minutes drying-FC.. but its tougher than it sounds!

I have very rarely gotten a complete panorama of notes from any coffee with less than 3 1/2 minutes steep time at proper brew temp and this at medium to medium-fine grind.


Aeropress is a little different and (without knowing all of the science behind it) you can usually get a good extraction with shorter steep times. I sorta mischaracterized my grind size a bit, really its more like a salt or sugar level grind, a little finer than you would grind for a pour over. Either way, I'll try some other SCAA methods to try to rule this out.
Roaster: Kaldi Fortis
Grinder: 1zpresso JX / Baratza Encore
Brew Method: Aeropress / Bonavita Drip

I love coffee, but roast a lot of charcoal
 
renatoa
Koffee Kosmo wrote:
...
In general I believe that your first crack is to early - try for 9 to 12 minutes to first crack
...
a light roast is best at least 3 min past first crack
...
KK


allenb wrote:

...
My own personal observations with my roasts is anything under 4 min for drying end to first crack start, except for those rare 5% killer, roast themselves greens that shine regardless how we mistreat them will come out with various taints in the cup.
...


Gathering this we arrive to the magical formula 5:4:3 , right ?
i.e. 5 minutes dry, 4 minutes brown, 3 minutes development.

This match partially with my golden profile, I develop less than stated, about two minutes, FC don't end usually in my roasts, still plenty of cracks when dumping.

primarist wrote:
...
Aeropress is a little different and (without knowing all of the science behind it) you can usually get a good extraction with shorter steep times. ...


Same experience here, from a "syringe" long time lover Grin
Anything over 2 minutes is too bitter for me.
Edited by renatoa on 10/23/2019 7:25 PM
 
renatoa
Related to the above, is good to refresh here the Artisan roast phases check in code:

Download source  Code

    #Flavor defect estimation chart for each leg. Thanks to Jim Schulman
    #http://www.home-barista.com/home-roasting/roasting-techniques-to-emphasize-coffees-origin-t3914.html#p42178
...
        #CHECK CONDITIONS
        #if dry phase time < 3 mins (180 seconds) or less than 26% of the total time
        #  => ShortDryingPhase
        #if dry phase time > 6 mins or more than 40% of the total time
        #  => LongDryingPhase
        ...
        #if mid phase time < 5 minutes
        #  => ShortTo1CPhase
        #if mid phase time > 10 minutes
        #  => LongTo1CPhase
        ...
        #if finish phase is less than 3 mins
        #  => ShortFinishPhase
        #if finish phase is over 6 minutes
        #  => LongFinishPhase
        ...





The above conditions, if taken as absolute truth, would led us to a minimum 3+5+3 = 11 minutes roast, with FC at minute 8.
Too short dry though, even matching the criteria.
Edited by renatoa on 10/23/2019 10:07 PM
 
snwcmpr
primarist wrote:
Great advice, I've been shooting for 4 minutes drop-drying and 4 minutes drying-FC.. but its tougher than it sounds!

If you are having trouble getting to the shorter times, then try a smaller amount of beans.

And

Charge Temp: 400°f (BT)

I am sure you mean ET, not BT.

Ken
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
primarist
I am sure you mean ET, not BT


Actually I am looking at the BT (the one that goes to the center of the drum) probe! My ET probe goes in past the drum, in the exhaust output. I've heard that a BT charge temp of between 350 and 400 is usually acceptable, do you think it may have caused scorching? The beans definitely dont look scorched at all. Any lower than 350 and my turning point is way too low.
Roaster: Kaldi Fortis
Grinder: 1zpresso JX / Baratza Encore
Brew Method: Aeropress / Bonavita Drip

I love coffee, but roast a lot of charcoal
 
renatoa
How do you measure beans temp in the center of the drum... ?

Charge temp can be measured anywhere... when empty and thermal stable, the temperature is uniform enough.

Scorching could be also due to drum too hot, not only air.
 
snwcmpr
I did not suggest a higher temp, I suggested less beans.
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
primarist
How do you measure beans temp in the center of the drum... ?


My BT probe goes in the front of the roaster and rests in the center of where the bean mass is when roasting. I don't pay much attention to ET while roasting (mostly due to my own inexperience!). As far as the drum itself being too hot, I'm not sure. I usually preheat for about 7-10 minutes if that helps?

Either way, the beans dont look scorched at all which is confusing! No visible tipping, the center-line is not burnt, no real facing, no internal scorching... I think I'm too inexperienced to know how to diagnose my roasting errors, just a little lost with all the possible variables.
Roaster: Kaldi Fortis
Grinder: 1zpresso JX / Baratza Encore
Brew Method: Aeropress / Bonavita Drip

I love coffee, but roast a lot of charcoal
 
snwcmpr
My inexperience with drum roaster still suggest that you are reading ET with the BT probe before you add beans. So, that should be correct.

When I had a Hot Top the highest I would drop ended up being 375° F ET.
At that point I reduced the batch size to get the RoR that I wanted to achieve a BT at the time I wanted. (If I recall correctly).

I hope that helps.

Ken
--------------
Backwoods Roaster
"I wish I could taste as well as I wish I could roast."

As Abraham Lincoln said "Do not trust everything you read on the internet".
 
allenb
primarist wrote:

How do you measure beans temp in the center of the drum... ?


My BT probe goes in the front of the roaster and rests in the center of where the bean mass is when roasting. I don't pay much attention to ET while roasting (mostly due to my own inexperience!). As far as the drum itself being too hot, I'm not sure. I usually preheat for about 7-10 minutes if that helps?

Either way, the beans dont look scorched at all which is confusing! No visible tipping, the center-line is not burnt, no real facing, no internal scorching... I think I'm too inexperienced to know how to diagnose my roasting errors, just a little lost with all the possible variables.


I also never pay much attention to ET which in my drum roaster is measuring the air/combustion gasses just before entering the back of the drum. This has never provided me with any useful information since there is such a complex mix of different heat transfer going on in a drum roaster. I only pay attention to the BT sensor which as you said, gives us inside the drum ET before loading beans to the drum.

Your short dry to first crack of 2:33 which requires a lot of heat input to pull off in a drum roaster, could be a source of your odd taste so I would definitely go for 4 or 4+ for that phase of the roast and see if the issue persists.

I'm a proponent of the traditional chafing dish cupping method for examining brewed coffee when trying to dial in a roast profile since it will give, if following the standard prescribed method, the best possible flavor that can be extracted from a given roast and can be a benchmark for determining how well any of our other brewing methods stack up and allows tweaking them for optimum brew quality. Using this method of testing eliminates the brew process as a possible source of the taint.

Table sugar size particles makes sense to me on grind size you're using for Aeropress especially for a short steep.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
allenb
allenb posted: I'm a proponent of the traditional chafing dish cupping method for examining brewed coffee when trying to dial in a roast profile since it will give, if following the standard prescribed method


Instead of the SCAA cupping protocol for coffee to water ratio, I prefer using 10 grams of a slightly coarser than table sugar sized grinds to a little over 5 oz of water and a steep time of 4 minutes which gets me close to the brew strength I shoot for using most brew methods.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
JackH
Roasting is a balancing act that is subject to experimentation. Too fast a roast and you leave uncooked elements that have bitter/raw flavors. Too slow and you bake off everything and have no flavor.

I would often smell the roast (easier on a turbo roaster) and catch a hint of the sour stuff burning off and changing to a sweeter smell. That is where I would stop.
---Jack

KKTO Roaster.
 
eddyq
IMO, the time from your dry end and FCs is rather short. In this time, the air temperatures are reaching max and you likely are scorching the beans. Scorched and tipped beans have a burnt taste even when underdeveloped. Do you see any tipping? (Black ends on beans)

Also, don’t be afraid of dropping sooner than 2min. My light roasts are 45s to 1:30 past FCs. And they are popping in my cooling tray. I pull espressos with them and they have beautiful juicy fruit flavors. No battery acid or vegetal tastes.

But I also charge at 370F, which slow dry times to a little longer than yours.
 
San Franciscan Roaster Co
primarist wrote:

Basically what the title says. I'm starting to get a bit frustrated as nearly all of my roasts have this astringent/acrid bitterness underneath all the other origin flavors; sometimes it can be very overpowering. Even my lightest, just-past-FC roasts still taste burnt. Here is an example of my most recent roast:

Roaster: Kaldi Fortis w/ Center 301 thermometer
Coffee: Washed Honduras San Salvador
Weight: 400 grams

Charge Temp: 400°f (BT)
Drying End: 5:12 (320°f)
First Crack Start: 7:45 (365°f)
First Crack End: 9:38 (385°f)
Drop: 11:35 (400°f)

Basically... how is this possible? The profile and beans appearance suggest a lovely medium-light roast. Instead it tastes like drinking battery flavored charcoal. Obviously this is part of the learning process, any ideas? Thanks!


Hey!

Just following along... I personally haven't roasted on this machine, but have spent much time on an SFR-1. I am not sure about the conduction heating ability of the Kaldi, but to eddyq's point the phase between drying and first crack is imperative to the beginning of sugar caramelization. While I personally do not roast like the this, MANY of my commercial roasting friends have begun experimenting with a an S-Curve i.e. slowing the roast down in the early development stage and creating more thorough pressure in the drum thus developing the interior and exterior of the coffee before first crack. This may allow you to accelerate through first crack to your desirable drop temp and roast degree without the underdeveloped taste you're experiencing.

Give er a try and let us know how it goes!
 
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