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Koffee Kosmo
OfflineAdmin
· 08/28/2020 7:15 PM
I have updated my signature and added links to the KKTO roaster build

snwcmpr
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· 08/16/2020 8:12 AM
I will say, it only happened once, briefly, to me.

NetriX
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· 08/16/2020 7:57 AM
I was blocked too, our hosting provider is dropping the ball lately. thumbdown

Koffee Kosmo
OfflineAdmin
· 08/12/2020 5:37 PM
And I thought it was just me that couldn't access the site All good now - coffee kept me company

JackH
OfflineAdmin
· 08/10/2020 8:46 PM
Had to make myself another cup of coffee to get through it.

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Temp dip after 1st Crack
AaronT
Hi everybody,

So I have been roasting for about a month now in a west bend Poppery II. I am tracking the heat with a cheap temp gun and I notice that once enter FC around (400 degrees F) the temp drops to around 330 degrees. then I have to build back up to get past 1st crack again. I am a dark roast guy so I like to take the beans out right at 2nd crack (460 F). Still a newbie but having to do 1st crack twice doesn't seem like a good thing.



anyone else experience this temp drop? Common?
 
renatoa
Is common to have a very small decrease of the rise, rather a flattening, not a real drop.
Such severe drop is something I didn't heard so far... and probably can be explained by the weirdness of infrared temperature measurement used by tour gun.
It's just due to the algorithm how the gun handle the massive IR storm coming from the beans after FC, probably it tries to compensate, or who knows... anyway it is not real for sure !
If the power and airflow are unchanged in the seconds before and after FC, then the real phenomenon that happens there should led to a temperature increase, the beans are into a heat-releasing phase for some seconds, then will follow a drop, but not so massive, due to the steam released in the crack process, that cool the beans. When the steam effect finished, the temperature increase resume.
This process can be found in literature as flick and crash.
https://blog.oilslickcoffee.com/2016/...ick-crash/

But, again, we are talking here about some degrees, not dozen...
 
JackH
I also see a small drop usually right before/during 1st crack. Some believe this is a result of the bean pressure release during 1st. Usually a very small dip in BT then it usually recovers quickly.
---Jack

KKTO Roaster.
 
renatoa
It can be noticed on RoR curve only, too small to notice on BT curve, as you can see from article also.
If noticeable by naked eye on a temperature tool, without rate of change display, then is a thing to investigate, something is weird.
 
JackH
You are correct, it is seen on ROR and not BT.
---Jack

KKTO Roaster.
 
snwcmpr
I have a drop in RoR from 20 where I like first crack to start. It sometimes goes to nearly 0 RoR, but I never let it go flat. In other words, close to zero, not zero. I roasted Eth Yirg Araicha a few times in the last few weeks. It only dropped to 14 RoR. The PNG Timuza A/X I did last night dropped down to 5 RoR.
If RoR is more than zero, then there is no way that the BT drops. If so, I would suspect trouble with the method of measurement.

Because of my hearing loss, I use the RoR as a way to know when the beans are cracking. Much like a canister releasing pressure, the cooling effect indicates cracking. The RoR drops as cracking starts. The beans volume rises in the glass. When the RoR stabilizes then I know cracking is done.
Ken
Thanks Allen for the roaster, thank you Jack for the Roastlogger.
--------------
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".
 
AaronT
Thanks for that. I have done another 9 batches since the start of this thread. I went down in batch size to 80 g and it helped immensely. consistent RoR. very happy with the product. I guess I was pushing the limits of the West Bend with the 100g size batches.
 
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