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Skywalker Roasts
amaller
Looks to be city/city+. I roasted this two weeks ago and there’s still no surface oils. No scorching that I see other than the 3-4 faced beans that I seem to have to sacrifice each roast. Overall pretty uniform for a decaf.
amaller attached the following image:
img_0402.jpeg
 
HarryDog
I think they look great, I have some guidelines I can use now, thanks.
 
HarryDog
This a decaf roast only 10% weight loss and I swear first crack was much later, (189c) I dropped at 193c as they were quite dark.
My chew test tells me they are already bitter and look like a 15% weight loss roast.

Note I marked the roast FC at 183c as I thought I missed it?
Not sure what to make of this roast, any comments, Thanks.
HarryDog attached the following image:
decaf-columbia.jpg
 
renatoa
You are right, that RoR plateau at minute 7 is the prelude of FC beginning.
Without power reduction at 40%, a flick probably would have happened.
Already a master of manual mode !
 
Isdel7

Quote

renatoa wrote:

Sorry for image quality, but this is the light available here... and old phone camera.
The duller image, with the tube shrunk, is the first adapter I did.
The second is an actual work in progress, thus the tube is in the non contracted state, as is sold.

When wires soldering and other electro-mechanical jobs finished on Nano board, will fully insert it into the tube, and apply a blast of hot air, hotgun or above a stove flame some seconds until it shrinks.

The tube is sold in electrical stores, or online like this: www.amazon.com/Di...ref=sr_1_1
~~~


Thanks a lot for that! I am going to try it soon. :-)

I also want to add one data point to the discussion regarding ambient temperature and how it affects roast times.
The usual temperatures outside during my roasts are between -5C and 5C, while in the room where I roast around 19C. I do have the exhaust pipe going outside through a window which probably affects things a lot. When comparing with other peoples' roast times and power settings, my times are significantly longer (never had a roast that lasted less than 10mins) and I have never seen a RoR larger than 11C/min. Also, I had a couple of instances where I was using the presets in AST mode but the RoR would plummet to 1C/min between DE and FC which forced me to overextend the development phase to reach a preplanned drop temperature. Perhaps not surprisingly, these batches were not great (still not too bad though).

I am now confident enough to roast in manual mode and I think that increasing the power a bit and/or decreasing the fan speed should get me to similar roast times. More batches to be roasted soon. I will report back if I have any interesting results.

However, I was wondering, is there any significant advantage to have a similar roast profile lasting 9mins say over a similar profile lasting 13mins? I mean an ideal scenario where all phase percentages are the same and so basically the same curve, just compressed over a shorter time interval. I have heard that the trend is to roast as fast as possible these days but I am curious why is that. Just starting my roasting journey so I still have no clue what I am doing.
 
renatoa
Check my post last days about my friend roasting at 15C degrees Grin

I don't think exhaust outside in the cold affects the machine, unless there is a strong wind blowing straight into the pipe.

1C/min RoR decrease is reasonable, same here.
I have typical 11C/min at DE, minute 4, and I plan entering into FC with 6-7 RoR value 4 minutes later, thus 4-5C RoR decrease spread over 4 minutes ...

The same for RoR maximum value... here 11C maximum too.
If TP is around 120C at 1:30, and DE is 3 minutes later in the 145-150C ballpark... 25-30C over 3 minutes... why and how should be RoR average higher than 10C ?
Keep also in mind that Skywalker RoR is computed as degrees per minute, literally as the definition.
Is not a short term RoR, as in Artisan.
Thus, when you read 11 at minute 3, this could mean RoR 13 in the first 15 seconds, then drop down to 12-11 at mid minute, and finish as RoR 10 for last seconds of the minute. What we see on display is the average.

Fast roasts comes from nordic school, using heavy convection heat transfer machines, different dynamics than ours.
My fast roastings so far, in the 7 minutes ballpark, not so many, only two I think, have resulted in underdeveloped beans inside, while the exterior looks darker than average.

It's easy to experiment, try 3 roasts using same profile allure, i.e. power change moments, but each having 5% more/less power than the others.
Then taste and decide what you like to drink.
Edited by renatoa on 02/16/2024 6:04 AM
 
HarryDog
Hello Isdel7, I basically do the same thing (Even lower temps), I open the door a bit and run the bathroom fan to stop any missed smoke from going down the hall. I have a board I slide in the window I put the vent in.

I turn off the furnace when I roast or it will draw the cold into the roaster as it pulls far more air then this roaster will generate. Might be some of the issue.
 
HarryDog

Quote

HarryDog wrote:

This a decaf roast only 10% weight loss and I swear first crack was much later, (189c) I dropped at 193c as they were quite dark.
My chew test tells me they are already bitter and look like a 15% weight loss roast.


Well I cupped this decaf, I want to call this imitation coffee because it does not taste much like coffee and the notes taste more like imitation flavoring?

What I get is a weak coffee tea note then as it cools a stronger sweet Malt, caramel-chocolate brownie taste that is very dominate.

I'm going to increase the charge temp and maybe go 2 degrees more in development. Maybe I can introduce some roasting notes and see if I like that a little more? By the way I thought it might be bitter, it still has room on that side to go darker.
 
amaller

Quote

HarryDog wrote:

Quote

HarryDog wrote:

This a decaf roast only 10% weight loss and I swear first crack was much later, (189c) I dropped at 193c as they were quite dark.
My chew test tells me they are already bitter and look like a 15% weight loss roast.


Well I cupped this decaf, I want to call this imitation coffee because it does not taste much like coffee and the notes taste more like imitation flavoring?

What I get is a weak coffee tea note then as it cools a stronger sweet Malt, caramel-chocolate brownie taste that is very dominate.

I'm going to increase the charge temp and maybe go 2 degrees more in development. Maybe I can introduce some roasting notes and see if I like that a little more? By the way I thought it might be bitter, it still has room on that side to go darker.



I have noticed that coffees coming out of this roaster seem to take way longer to off gas than from the fresh roast that I used before. Maybe that has something to do with it? Weight loss also isn’t super reliable for decafs since they tend to have lower weight loss than regular beans.
 
ctjameson
So I haven’t been able to reliably get more than about 2 back to back roasts out of this thing before all hell breaks loose and the element goes into overdrive and turns on full blast and I can’t turn it off without literally unplugging the roaster and letting it sit and completely cool down. I think there’s something wrong with mine maybe. I’m going to reach out to ITOP about it I think. I hope their guidance isn’t just “wait for it to fully cool between roasts” because that would defeat the whole purpose I got this thing for. I’d ideally like to get 4 full pounds before needing a cool
Down cycle
Skywalkerino - Arduino/artisan powered Ali Roaster
 
renatoa
I did three roasts back to back first days of initial testing, so there is no need to wait for complete cool.
Actually, started using the COL mode only recently.
 
Mike_Mathis
@ctjameson there is a thread that mentions this issue on Facebook group fresh coffee roasters. Started by a guy named Alex. It should be toward the top.
*Kaffelogic Nano 7
*Skywalker V1
*2023 BC-2
 
ctjameson

Quote

Mike_Mathis wrote:

@ctjameson there is a thread that mentions this issue on Facebook group fresh coffee roasters. Started by a guy named Alex. It should be toward the top.


Could you DM me a link to that group? I can't find one with that exact verbiage.

TIA!
Skywalkerino - Arduino/artisan powered Ali Roaster
 
renatoa
Possibly this: https://www.faceb...819774625/
It's a private group, so can't search further inside.
 
amaller
Has anyone tried the Ethiopia Dry Process Senna Katta Mountain that was on special from SM about a month ago? I roasted a batch last week and it seems like a miss. Lots of quakers and way too much size variation to get a decently even roast. The profiles on this machine seem too high powered for natural process bean. Thinking I’ll have to get artisan set up for manual roasting sooner than later…
 
renatoa
Try manual mode, using what I posted in #8 as a starting point.
Probably today I would lower power even more, to 35%, and drop after 7 degrees development.
 
Mike_Mathis

Quote

amaller wrote:

Has anyone tried the Ethiopia Dry Process Senna Katta Mountain that was on special from SM about a month ago? I roasted a batch last week and it seems like a miss. Lots of quakers and way too much size variation to get a decently even roast. The profiles on this machine seem too high powered for natural process bean. Thinking I’ll have to get artisan set up for manual roasting sooner than later…


I purchased one lb of Senna Katta Mountain recently from SM and roasted it on two different roasters. It was ok but I didn't care to purchase it again. I roasted 350g of it manually on my SW and cut back on the suggested heat from the stock profile (22). I roasted the balance on the Kaffelogic and though it was better, wasn't anything to write home about. I also purchased 2 lbs of Ethiopia Sidama Shantawene from them and after roasting one time ordered 2 more lbs. The Sidama may well be the sweetest coffee I have ever drank to not put sugar in it. It is very flavorful, hence the repurchase. I will roast the Sidama on the Kaffelogic only, as I have taken someone's profile and tweaked it to suit me to a tee. I realize you didn't ask about another coffee, but I couldn't help myself.
Edited by Mike_Mathis on 02/23/2024 6:42 PM
*Kaffelogic Nano 7
*Skywalker V1
*2023 BC-2
 
Mike_Mathis
I did my first roasts today with the Skywalker Spy hybrid control setup. Interestingly, the adjustments are curved lines as if it is reading the watts by the single digits. If that is true then this is some extreme accuracy. I also liked how the temps on the controller pad and Artisan were in exact lockstep. I noticed when ending the roast and pressing "P" to cycle to "COL" mode, the roaster shut off. I left it in "COL" and just pressed the power button to turn it back on and it went straight to "COL", so that's ok. It didn't shut down Artisan recording which is the issue I had with the other Artisan control scheme. This is far from a perfect roast (if there is such a thing) but I am happy with the results.

I'll drink it! Thanks renatoa. You are one smart cookie!ThumbsUp

Edit: 4-4-24 After 15 days, the Costa Rica is really developing into some very flavorful coffee.
Mike_Mathis attached the following image:
costaricalamagnolia.jpg

Edited by Mike_Mathis on 04/04/2024 9:08 AM
*Kaffelogic Nano 7
*Skywalker V1
*2023 BC-2
 
Mike_Mathis

Quote

renatoa wrote:

The only out of the box button meaning redefinition I did, was to use the factory defined FCend button as heater cut-off, at the end of the roast.
So, the roasting routine for finish is: wait for FC, mark, wait for development, press FC end, i.e. heater OFF, open the dump door, press DROP = starting cooling.

~~~

Who knows what nuggets one might find when looking back at posts that went by without grasping. I have now assigned my FC END button in my command.ino schemes. Since I use alternate bean cooling exclusively, I assigned DROP to run exhaust fan at 100%.

Spy takes care by control pad the Chinese sent me. All in all........everything is working and coffee tastes good to me.beach
*Kaffelogic Nano 7
*Skywalker V1
*2023 BC-2
 
renatoa

Quote

Mike_Mathis wrote:

...I also liked how the temps on the controller pad and Artisan were in exact lockstep. ...


Thank you to endorse the new formulas translating raw data to temperature, used in last build of SkyscannerSpy.
 
Tech2C
Hi all,

I bought the ITOP CBR\Skywalker roaster last month and have been experimenting with roasts. It is a learning curve but it has produced some great tasting coffee.

I wanted to roast smaller batches than 250g\330g as I buy coffee in 1kg bags and that only allows 3 or 4 roasts to get it right.

As such, I roasted down to only 85g which still registers on the thermocouple, but it under reads by about 10c. First crack occurs at about 173c when with larger batches it reads 183c.
The infra-red heating is unique. It roasts with radiant heat prominently, followed by conduction, but the drum isn't that thick. I'd call it a cage instead.

Anyway before I roasted such a small batch, I wanted to know how hot the heater is. As a test I stuck an external thermocouple PT100 into the trier hole, and it settled at 230c with only 40% heat power! Turning on the fan, even the minimum 5%, was enough to drop the temperature 10c.

With this info I roasted the small batch at only 40% heat with the fan at 5%. 5% is enough to evacuate the smoke I find. Preheat temp was 160c.
The 85g roast completed in 9:30mins, weight loss of 14.2%, final temperature reading of 180c, but most likely about 190c. I didn't change the heat or fan throughout the roast so the ROR was a constant 7c for this test.

It was only yesterday so I'll report back on taste in a few days.

Even when roasting at such a low power, the usual half dozen black beans were still present!

The infra-red element is very efficient to roast coffee. Here I roasted 85g with only 400w power! (besides preheat of course)
 
renatoa
Welcome !

You are right about the unique nature of IR roasting.
The good news is that if you found a good profile for 250 grams, you can apply same power changes to lower charges, and have close results, because IR has the same energy for any load, and the coffee bed is just slightly smaller, as surface.
This is all matter in radiant transfer: power, and distance/surface.
Volume of air is a lot less, or no more relevant at all, as for convection.
However, less beans means less layers, and faster beans re-circulation... thus more exposure to radiation... another factor that should be taken into account.

Does your newer roaster model provides drum speed change, as they promised ?
Lowering speed could help to get rid of charcoal burnt beans.
Half dozen... that seems a lot... never had more than 3-4 for 250 grams batch.
Edited by renatoa on 05/19/2024 3:17 AM
 
Tech2C
Thank you!
No speed change for the drum unfortunately. It is a ritual to search for burnt beans after every roast.
 
HarryDog
I Have added Renatoa's Temp & filtering code along with the cristianku multiple commands code and did some minor changes to load it on the ESP32. I used the TXS0108E logic converter and just finished some roasts. I had the sampling rate at 1 second and the filtering at 70%.
HarryDog attached the following image:
esp32-crt.jpg
 
renatoa
The Taming of the Shrew Grin

...on the eastern front, I want to report something related to burnt beans...
Replaced recently the motor with other model... long story, will come later with a detailed post in the mods thread...
Seems like the new motor is slightly faster than the original, even if both are sold as 60 RPM.
The effect is that I have a lot more beans jumping in the drum higher than before, up to the lamp level... and the result... more burnt beans.
Counted 8 charcoals the last roast, for a 250 grams load, which is huge for me.
Planning to add a PWM speed control, in order to reduce the speed until I have a mild rolling/cascading of the beans bed, instead the wild cataracting I experience now.
renatoa attached the following image:
image_2024-09-09_121655588.png

Edited by renatoa on 09/09/2024 4:18 AM
 
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