Green Coffee Buying Club
Coffee Discussion boards => Hardware & Equipment => Topic started by: kwksilver on May 29, 2008, 01:07:33 PM
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hi guys,
I recently acquired the gene that was for sale here, and I am wondering if I could dip into some wisdom of fellow owners here.
My prior roastign experience is with modded popcorn poppers and stovetop style.
I have used a cheap and slow thermometer in the past to correlate temperatures to bean stages. That seemed to work well.
With the gene I am just starting to explore the machine. So for now my goal was ramp to 1st crack at max temp setting (484)
and then scale back heat production by setting a target temp of 440. I tried stopping it when I am a few seconds into 2nd where the large smoke increase is.
My problem is that hearing 2nd is difficult, and I am not convinced the displayed 440F are really there. With my popper by the tiem that thing read 440 I was very deep in 2nd and smoke was there. (I really that thermometer lagged behind)
But even with 20 minutes at a max temp of 440 the gene does not bring out appreciable smoke or an oily sheen on the beans.
It is not that I want my beasn that way, but I have to understand every stage to know when I want to stop her.
Does anybody know about accuracy of that thermometer in the gene? Is that just an arithmetic estimate based on heate rinput maybe?
What is going on here? What would a fast K type thermocouple be telling me? (I cannot do that here no idea where to put it even if I had one with the gene).
What would you expect the beans to look like after they have done a 20 minute roast with 440 after 1st crack? (hustled to first crack with max ramp)
I clearly have a learning curve with the gene. If the temp is an estimate, could that be thrown off by a weaker outlet? (this outlet has served me well with the poppers they used a similar wattage, dunno bout amperes)
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First, the temp that is being read back to you is from the exit thermocouple and is not at all representative of the bean mass temp.
Second, try using a consistent amount of beans. I use 283 grams (10 ounces, loss easily calculated) and try to stick with that amount.
The higher the altitude at which the bean was grown, the higher the initial temperature setting should be. Accordingly, try these beginning settings on your beans:
* Yemeni, Africans, Central American - around 470 degrees
* Brazilians, Island, Indian - around 460
* Decaf, Konas - around 450
(Some start with a lower temp and hold it when it reaches about 350 for about 3 minutes, to develop the sugars), then raise the temps. Compare the roast of identical beans and see if you discern a difference in taste.
After your roast hits first crack, let the beans move through the crack for 30-60 seconds and then turn the unit down 20 degrees. That profile works for me. I am grinning because I trying someone else's profiles lately whom I respect and the beans ended up without sufficient fruits. Profile was too flat.
My voltage is usually around 119 and drops to about 116V as it cycles through. Not sure why you aren't drawing some oils at 20 minutes but you didn't share the weights with which you are working. Less beans will take longer (if memory serves me) as there is greater flow-thru of heat and less temp build-up in the bean (I would need to check my notes - got into an argument about this and wanted proof).
B|Java
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Hey BJ, reads like some great advice. This gives me plenty of little experiments to do.
You are referring to specifically the Gene yes?
So the thermocouple reads the air temp exiting the chamber, going to the chaff bin? (good to know)
Is there a rule of thumb that lets one estimate rough bean mas temps? I expect that to obviously be lower if I am heating and slightly higher when I am holding or cooling. I understand that this differential has to obviously vary, but I don't even have a feeling for the ballpark here.
Again, thanks a lot BJ! (I had found that 350 holding thing before, never knew what the purpose was)
So do I understand you correctly in saying that you do not subscribe to ramping the initial roast at maximum setting on the gene?
Regards,
Felix
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Yes, the Gene.
I can't give you readout:bean mass ratio. Don't know. Also depends on amount roasting and time to cycle into the temp you are trying to achieve.
350? All B'Whispers and PeterPetunia's professorships. I listen. Alot.
No way I just crank it up to 481. Always gives me a bit of burnt roast flavor that I don't care for. Our West Coast friend has that on his website and I think it is a disservice to the machine (or he used to, I should recheck).
Pyment is very good on the Gene and he is a fiddler with profiles. I like repetition, if and when I follow my own advice.
B|Java
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http://coffeeproject.com/roasters/gene_info.html
The aritcle I wrote for Coffeeproject on the Gene.
B|Java
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WICKED!
GCBC seriously came through in the form of bold Java.
excellent, thank you.
Felix