# Gene Machine temperature readout



## mathof

I've just roasted my second lot of beans on my new Gene Machine. I followed one of the profiles recommended by Bella Barista (Gentle Rise, Gentle Finish) which calls for several changes of temperature. My problem was that I could never tell if the machine had reached the indicated temperature. For example, I was waiting for the green beans to reach 220C (which I had set as their first target), but as the digital display climbed to 219 and then maybe held there for a moment, it dropped back to 216 and then climbed back up to 219 and repeated the sequence. Eventually, I decided that, as the anticipated 9 minutes had passed, it must have reached its target, and I proceeded to the next stage. Similar problems occurred at every temperature. Is the display meant to hold firm at the set temperature when it reaches it?

I should add that I did this roasting on my terrace with overcast skies and a slight breeze. Perhaps this affected the temperature?

Matt


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## froggystyle

This is where the gene hits temp and then shuts down the heater, the temp then drops and the heater starts up again, ramping up the temp.

Its a tricky one to master, but a few have done the dimmer mod which helps...

I tend to set it to a temp i want and leave it, maybe dropping down after first crack, lots of info in the home roasters section, which you should read, plus Davecuk is the man to ask about this machine, in fact he wrote the instructions you have!

Never roasted outside as i fitted a flu to the gene going out the window, but i can imagine the winds will cause heating issues.


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## froggystyle

Just to add, my first three roasts were terrible, had to dump them!

Stick with it and youll soon master the machine and have decent roasts coming out!


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## johnealey

Hi Matt

If you keep a close eye when you start to see the temp read out getting around the 215 mark you will see it flick from 220 to 2.1.5 then up to very briefly 2.2.0 the dots in the display indicating the measured temperature vs the set temperature. As froggystyle sais above it will then cycle dropping back to 2.1.5 or 2.1.6 and then back up to 220 then drop etc. If you time your 1 minute hold from the first time you see 2.2.0 appear before you take it up to 230 ( same when looking to hit 2.3.0).

What beans are you roasting at the moment as may be able to give you a very time, won't be exact as everyones voltages are different leading to different timings etc.

Keep at it.

John


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## mathof

Thanks very much. I was wondering what those dots meant. I'm roasting Columbia Yellow Bourbon Las Margaritas La Esperanza.


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## johnealey

Hi Matt

Not roasted that particular one but roasted a Coffee Compass Columbian Finca Santa innes Antioquia that was hitting 220 between 5m40s to 7m30s over 3 roasts a week or so apart so you may be a little out at 9 minutes on an unmodded 240v gene. The brazillian Bourbons were hitting 220 at about 7m50s to 8m20 over about but may be a slightly softer bean than its Columbian cousin.

Hope this of help, the daily roast thread also a very good source of time / temps etc.

John


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## NickR

4 degC ie 216-220degC is not going to make much difference to the beans actually temp. Read it as 220c. Why were the roasts terrible?


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## mathof

NickR said:


> 4 degC ie 216-220degC is not going to make much difference to the beans actually temp. Read it as 220c. Why were the roasts terrible?


I don't know. I did the roasting last night, and I'm letting the beans degas before I try them. I just want to understand the machine at this point.


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## froggystyle

I would go with a simple profile to start with, pick an easy bean also.

What beans do you have to roast?


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## mathof

I have three types of green beans here, all from Bella Barista: India Monsoon Malabar AA; Old Brown Java; Columbia Yellow Bourbon Las Margaritas La Esperanza.

I don't know if these are easy or difficult beans. And although the handbook that came with my Gene Machine outlines various profiles, it doesn't say what results to expect from each of them. So I have no basis on which to choose one profile over another.

Thanks for your interest.

Matt


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## froggystyle

The MM are an easy bean in terms of hearing the cracks and roasting, plus you dont have to deal with chaff..

Try 230g in, set temp to 235ish and turn the timer up to max, then have a seperate timer running from the minute you hit go.

Aiming for about 13 minutes, this all depends on what level of roast your after of course.

You will easily hear the first crack as they are very loud, about 10.30-11 mins.

I found them a nice bean, easy to get a level coloring on the roast, as an espresso on its own i didnt find it that exciting though, try mixing some of the with your Columbian after roasted.


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## mathof

By "try 230 in", do you mean to preheat the machine to 230, or to put the beans in the cold machine and aim for 230, before raising the level to 235?


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## froggystyle

Sorry, put 230g of green beans in at cold, then set temp to 235c and go from there.

Wouldnt bother with pre heat, i used to but have since dumped it and dont see any difference.


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## 4085

If you do 2 roasts back to back, same beans the second roast will always be faster than the first.....preheating! Are you recording your roasts data?


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## froggystyle

Kind of, but if your using the cooling cycle then your bringing the heat of the drum down to almost your starting point...


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## mathof

I've followed your instructions best I could. I was aware of first crack at 11.49 minutes, when the temperature had reached 231C. (It probably started before that, but by the time I noticed it was cracking like crazy.) The temp reached 235 just as 13 minutes expired. Does that sound about right? I let it go another 30 seconds before starting the cool down phase.

The result looks very pretty. I look forward to mixing it with the Columbian I roasted yesterday.

Matt


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## froggystyle

Stick a photo up, everything sounds ok!


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## NickR

The thing about the Gene is thats its noisy, your lucky to hear cracks at all. I generally go by colour and chaff removal. You learn to stop the roast just when the chaff has seperated from the majority of the beans and the colour is slightly more pale than the colour you want the beans to end up. It sounds a bit daunting put like that I know, but actually its very easy once you get to know the machine.


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## mathof

froggystyle said:


> Stick a photo up, everything sounds ok!


Here it is, photographed just after the cool cycle completed:









Matt


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## froggystyle

Looks like you nailed that roast, well done!


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## NickR

They look great, better than my roast of today.


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## johnealey

The Old Brown Java you have, whilst giving off a huge amount of chaff in the early stages, will give you a similar easier roast to understand in the same way the Malabar does ( will also look equally as nice) and take about the same time roughly.

Your roast looks nice and in the right ball park for working out how far to go on the next one.

John


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## DavecUK

Those look good, you're getting the hang of it now.


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## froggystyle

DavecUK said:


> Those look good, you're getting the hang of it now.


Dragging up an old post here, Dave, in your sig you say full power control mod for the 1200, have you done any write ups on this mod?


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