Manual roasting using ET only

[Steve]

More cupping, brewing and espresso I am still not satisfied with my profiles.
The higher airflow tends to leave things thin and wispy, the cup lacks structure and even though there is no astringency I dont think any of the roasts are particularity well developed. Lower airflow just increases baked brown flavours. This is after cupping the Worlds Largest Cupping coffees twice against my own KL roasts as well as others from here over the last few days.
Square Mile quality green / roasts are really world class...

Have been working my way through a bag of fresh washed Indian beans, basically should be super smooth, sweet, big body creamy milk chocolate a bit bold around the start of 2nd crack

The following readings come from a very long 3 mm K type probe bent under KL bead sitting in the middle vent of the black hot spot in roast chamber.

This is what I have landed on after another 20 or so roasts trying different things.
The roast is basically a 3/3/3 profile and fits into well established guidelines for roasting purely by ET with an air roaster.

I am still getting my head around how to best turn this into a usable profile?
Power profiling is definitely in order and I will have to fiddle with appropriate fan profile to mimic my changes during the roast.

After going through this manual roast process again (after 1 year of bashing head against wall) with an open mind / starting over, feeling like I would love a KL probe that is fully sheathed and bent down at a right angle into the same spot as my 3mm K type probe.
Could this be done as an added extra for those wanting to abandon the chaotic ROR / bean temp readings? Which I am starting to think are pretty much useless no matter what machine you are roasting on....

The espresso this roast produced straight after roast, ground on Niche, pulled on BDB with flow profiling mods completely floored me, super sweet, big creamy body, as clean as an Indian coffee can be, reminded me of great medium - dark roasts I have had from commercial drums but a lot cleaner, bold chocolate in a milk drink.

Any comments or suggestions are welcome, still just trying to get the best out of this little beasty.

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ManS2ndcrack.klog

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[Steve]

OK so another several roasts creating a profile for proof of concept from the manual roast.

With the lid off the roast chamber there is a definitive loss of heat requiring substantially more power 100 - 200W extra to maintain a profile.

With my external venting on a low draw the loss is less / pretty close to having the stock black lid on.

Put a hole in the black lid for the long K type probe to go through into roasting chamber.

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As with many things in life it turns out that simplicity is often best, could it be this simple?

Locked power profile (1200W) until just after first crack end where the ET will start to drop off, then use 2nd "zone" with a ramp % up in power to what ever you want to finish at.

This roast hit start of 2nd crack at 1300W with room to move if one wanted to stretch out DEV to 3:30 or beyond and stop the ROR flicking so hard, just requires experimentation with end power calculation over that specified time.

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The devil is in the details of the fan profile which takes care of keeping a steady RISING ET profile throughout the entire roast which is what stops the roast from UNDER DEVELOPING and BAKING.

I assumed for quite some time that keeping the POWER PROFILE steadily rising throughout the roast would do this automatically but it turns out this is most definitely not the case and I was wrong.

Fan profile starts at a whopping 16000 RPM which gives excellent agitation right from the start, throughout the roast it drops to 13500 RPM where it stays stable into FCS until finished.

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The Environment Temp profile degrees C : (can not log in Artisan because of electrical noise)

0:30 - 190
1:00 - 199
1:30 - 204
2:00 - 205.7
2:30 - 208.7
3:00 - 212.2 = Yellow
3:30 - 219.3
4:00 - 223
4:30 - 228
5:00 - 236.5
5:30 - 242.5
6:00 - 247 = First Crack Start
6:30 - 250
7:00 - 252
7:15 - End Of First Crack
7:30 - 254.3
8:00 - 256
8:30 - 262
9:00 - 262 = Start Second Crack

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IEH2ndcrack.klog

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[Steve]

Graphed the ET profile using KL studio, just need a new probe and updated temperature settings in the software yes I know I am a dreamer.

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[Steve]

Back to the washed Ethiopian Guji.

Several manual roasts dialling it in, after which I decided to use the information I had to make some guesses and create a profile for it. I wanted a roast around the same time 9:00 as the dark roast so need a more gentle start then carefully ramp up the heat, which I did not do that well.

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Simplified the Fan Profile

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Made the KL bean temp ramp a straight line as a guide going off the start of the manual roast. Made some guesses around the power, I wanted a little bit more at the start then a more gentle ramp which the zone 4:00 to 8:00 worked quite well.

Ground straight off roast waited 20 mins and cupped it and its very promising, the viscosity was immediately noticeably more syrupy in the mouth and just pushing on the surface tension in the cup with spoon.
Sweet, red fruits, much longer middle and milk choc finish. Will keep testing it over next few days, colour looks spot on.

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[Mark]

Wow ... I admire your dedication Steve ... your a real credit to this little community.
Please keep up your good work ... it's much appreciated by all of us I'm sure!

Cheers Mark

[Steve]

Cheers Mark, still learning heaps over last couple of days about what all this means.

[Angela]

Wow ... I admire your dedication Steve ... your a real credit to this little community.
Please keep up your good work ... it's much appreciated by all of us I'm sure!

Cheers Mark

Spot on comment! I totally agree.

[fnq]

Hi Steve

i just used your EH2ndcrack log to recreate your profile at that time. My log is attached... and falls away from the profile ( only gets to KL 232 degrees as opposed to your logs 238, so prob not second crack and not making 5.1 roast level?

After rest for just under 3 days,- i am missing the sweetness. I have a dark roast flavour but not ashy, seems a bit thin on first taste but finishes with a really textural buttery finish and aftertaste. (certainly some good traits worth exploring)

Sorry i have missed the 'creating profile' sessions ( last one was june just before i got my KL) so newbie questions/ thinking.

My power, power factor and calibration are slightly different, ( what else isn't imported when i recreate a profile from your log?/)

Without taking up too much of your time could you suggest options emulate your roast without overly lengthening the roast time.
cheers Darryl

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[Steve]

Hi Darryl,

These were just exploratory roasts and the MET thing is a bit of a dead end BUT this did help generate further ideas about early roast development.

I and a couple of other people have spent considerable time and greens testing many other things out culminating in what I think could be the ultimate "baseline" profile or starting point for what ever one might want to roast. Ive been waiting to see how things pan out before writing yet another profile journal.

Main points:

Applying correct amount of heat at the start of roast by taking control of the first 1:00 to1:20 with a power profile = apply heat and see what curve is generated and fine tune "profile" after for PID to follow on subsequent roasts.

Constantly Declining Fan Profile = no fixed high RPM fan speeds or flat spots ever = no more power issues and hopefully no baking. Draw a diagonal line through the Classic Fan Profile and you will be pretty close.

Max time around 8 min for med - dark roasts
6:30 - 7:00 for light roasts

[fnq]

thanks Steve

I will take heed of your suggestions and look forward to future developments.

Again, I appreciate your efforts and willingness to share. Cheers Darryl