Reroasting Unfinished Coffee Beans

paypalboutique

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I roasted some Robust a Mexican Agatha Chiapas, Soconusco beans yesterday for 17 min. And didn't hear 1st crack. I ejected them from my B2-2k Hot top roaster and they are light brown with 13% weight loss no smoke. Today they smell and taste grassy. Can they be finished using a popcorn popper?
 

namballe

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i don't see why not. i have run into this problem before and had to re-roast with good results. what was your batch weight and temp? 17 min. in and no 1c?
 

paypalboutique

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Start weight 250g finish 217g 13% loss. start temp 225, turn temp 340, finish 400. Ambient temp 20 deg F humidity 45%. I thought I heard a little pop at 14 minutes. Total time 17:29. I used the popcorn mach. to further roast. It still tasted grassy. Today I tried roasting a new batch with the popcorn machine. 66g weight start, 52g finish with 21% loss. Start temp 225, turn 430 finish 520. Ambient temp 15 deg f humidity 61%. 1st pop 23:03, end 25 min. Finished 28:43. Couldn't hear 2nd pop. Brew tastes burnt and was dark roast. Either it was too cold or the bean sucks for cracking.
 

JumpinJakJava

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Start weight 250g finish 217g 13% loss. start temp 225, turn temp 340, finish 400. Ambient temp 20 deg F humidity 45%. I thought I heard a little pop at 14 minutes. Total time 17:29. I used the popcorn mach. to further roast. It still tasted grassy. Today I tried roasting a new batch with the popcorn machine. 66g weight start, 52g finish with 21% loss. Start temp 225, turn 430 finish 520. Ambient temp 15 deg f humidity 61%. 1st pop 23:03, end 25 min. Finished 28:43. Couldn't hear 2nd pop. Brew tastes burnt and was dark roast. Either it was too cold or the bean sucks for cracking.

15deg.F temp? Did you roast outside? What do you mean by turn temp 340deg.? I always understood turn temp to be when the original temp (drop the beans,) then bottoms out after about 1:30+ min., and then starts to reclimb in temp. Temp turns to rise to finish roast.

Is there a P.I.D controller hooked up to your popper? Or modified some way to read temps? 520degrees?
After 28 min. the beans should be charcoal. Unless you did roast outside in that temp.
Years ago, living in New England, extreme weather made it difficult roasting outside. I built a wooden box for my
old West Bend Poppery 1. Worked good in the Fall. But Winter was tough, so I smoked up the garage doing a number of roasts.
I had good results, but would not say great. Still better then buying roasted beans around my area.
 

John P

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First, no coffee roaster is meant to be used at lower than room temp. Even if you're a garage roaster, you need a heated garage. Get below 60F is bad as an ambient temp.


17 minutes is long.

225 is kinda low and shouldn't be used for that type of bean.

270 would be more like it.

Charge drum to temp, beans in, establish temp of 270. (maybe 1 min 45 sec) TT = 1:45
3 min from 270-300, TT = 4:45
5 min 45 sec from 300 to 400, TT =10:30
2 min 30 sec to finish. I'd recommend about 422-435max (based on those beans.) TT= 13:00

Or shorten then 300-400 by one minute.


And it sounds like your temp probe is inaccurate or your roaster heats way too slow. If you cannot reach the temps in fast enough time and maintain momentum in the roast, your roast is constantly in a state of stalling. This never allows sugar chains to build or flavor development to occur. This will result in coffee being either over-baked or under-baked, but it rarely results in them being roasted.
 

paypalboutique

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15deg.F temp? Did you roast outside? What do you mean by turn temp 340deg.? I always understood turn temp to be when the original temp (drop the beans,) then bottoms out after about 1:30+ min., and then starts to reclimb in temp. Temp turns to rise to finish roast.

Is there a P.I.D controller hooked up to your popper? Or modified some way to read temps? 520degrees?
After 28 min. the beans should be charcoal. Unless you did roast outside in that temp.
Years ago, living in New England, extreme weather made it difficult roasting outside. I built a wooden box for my
old West Bend Poppery 1. Worked good in the Fall. But Winter was tough, so I smoked up the garage doing a number of roasts.
I had good results, but would not say great. Still better then buying roasted beans around my area.

I roasted outside for the 15 degrees F. For the 340deg turn was my first roast using the Hottop outside at 20 degrees ambient hum. 45%. The 340 deg turn was the internal barrel temp at which I noticed the beans turning brown. I used a laser thermometer to guesstimate the temp of the popcorn popper and it registered 520 degrees outside and when I brewed the black beans, it tasted slightly burnt. As for my 28 minute roast, that was the 15 degree outside ambient. I was using the popcorn popper, a nostalgia popcorn machine 1,095 watts. I used the same popper for a Vietnam bean and it only took 5 min 49 sec to get full city roast at 41 degrees at 68% hum.

My hottop roasting takes awhile because, a chime goes off at barrel temp of 167 deg F, but the manual says to put beans in at 225 deg. Once I put beans in, temp drops to 160.
Manual says to turn fan on 25-50% and drop temp to 50% once it reaches 200 deg for 30-60 sec to dry out beans.
Once temp reaches 259, drop fan down to 25%.
At 280 degrees turn heat up to 70-80%.
At 300 deg, turn heat up to 100%. If smokes, turn up fan.
Around 4 more minutes about 360 degrees watch for browning.
At 370-375 deg, turn heat down to 50%.
at 400 deg - 1st crack should occur, turn fan up to 25%.
1st crack ends - 1:30 - 2 minutes.
After 13 min 30 sec, turn heat down to 30%.

What I noticed about their instructions is it takes a long time to roast the beans. It seems like they are baked instead. All the youtube vids show the guys not using the fan, but they get a lot of smoke. When I use the fan according to the manual, it keeps the smoke down. My last Hottop roast took 21 min 33 seconds to achieve light city roast. I started with 250grams of beans and ended up with 226grams. Started roast at 168 deg, noticed browning at 350 and finished roast at 420 deg. in the garage it was 32 deg at 67% hum. First pop was 16 min 58 sec, ended 17 min 50 sec. 2nd pop was at 21 min and 3 sec. 1st pop was very heard to hear. 2nd pop was more predominant. I brewed it a half hour later and the beans seemed small and light when grinding. The coffee was watery. I primed it for 30 sec and saw a lot of co2 and brewed for 4 min with proper temp 6 oz water at 11g of grinds. Either it was the roast or the beans are crappy. I'm going to try to roast the Vietnam beans and see how that came out. I loved the flavor on the Vietnam when I used the popcorn machine.
 

John P

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Jan 5, 2007
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Peter,

there is that.:D And I would like to add, there is no such thing as "tasty Vietnam beans". They are firmly seated at the top of the bad coffee bean list.

PPP,

Maybe you should steer clear of coffee. You have a questionable palate.
 

paypalboutique

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I was only comparing the 2 robustas. I haven't tried roasting Arabica yet, but I have a sampler pack on order from Sweetmarias.
 
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paypalboutique

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It worked. Yesterday I used my Hot top and got to 1st crack. I ejected too early. The brew tastes grassy. Today I took them and reroasted them in a heated garage for 5 min. And got to 2nd crack dark Italian roast. The Mexican robust a bean I'm working with gives me weak caffeine no mater which roast I perform.
 
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