Start of profile - Issue or not?

[Geronimo]

Greetings

I always get the start of the curve very different to what other people post for various profiles, and have tried many profiles.

Granted it is cooler at the moment. This stock profile 1200-1500m Rest, has a higher than normal pre-heat which expect to be a good thing given the cooler ambient temperature.

Any thoughts anyone.

Cheers
G

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[Howard W]

I have no idea why there's a slower start in the initial 30 seconds but my guess is that it won't matter much if it follows the profile curve subsequently. Are the roasts to your liking?

[Geronimo]

I have no idea why there's a slower start in the initial 30 seconds but my guess is that it won't matter much if it follows the profile curve subsequently. Are the roasts to your liking?

Hi

Thanks for comment. Just trying to find out if maybe there is something wrong with the roaster, or other simple explanation such as ambient temperature. It does seem weird when I look at other peoples curves that are posted, their roast curve follows the gradient of desired roast curve initially, as in it is steep from the kick off.

It was suggested by Steve in this group who is very knowledgeable with respect to commercial roasting and suggested a higher pre-heat, but doesn’t seem to do much.

The jury is still out on taste as many of the profiles within my power constraints I’ve tried have quite a bit of tipping and I feel more burnt beans than there should be with a roaster that is supposed to produce an even roast. I am now trying the altitude profiles just posted. However yesterday’s roast of Brazil Cerrado on the 0-1200m Rest profile still has an unacceptable amount of beans with tipping evident. I pushed them to a roast level of 5.0 because I want to put them in a blend for milk.

Circulation of beans is definitely an issue with this roaster, and tweaks to fan is required, as others have found, but in saying that the vanes which the air enters the roast chamber, I feel should be at more of an angle, to allow more fluidisation of the beans, because if you get the initial weight wrong for your fan speed, the beans swirl around in a circular motion, rather than bubbling upwards, and possibly cause beans on the outside to be in contact with the steel chamber longer and scorch. Conversely happens if to much weight of beans, not enough movement, and again possible scorching.

Cheers

[Howard W]

Hi Geronimo, yeah I'm trying to find the sweet spot for fan profiling as well. Seemed to have got the ROR smoothed out using higher RPM but I'm keen to get rid of the scorching completely (albeit quite mild but I'm trying to do very light roasts so any tiny bit of scorching would seem particularly apparent). I haven't tried the timer mode yet, it'll probably help to make sure the starting agitation looks alright. Did a search for how an ideal fluidised bed looks like and wonder if we can replicate this on the kaffelogic:

https://www.youtube.com/watch?v=sBMnw6Wwzi0

[Geronimo]

Hi Geronimo, yeah I'm trying to find the sweet spot for fan profiling as well. Seemed to have got the ROR smoothed out using higher RPM but I'm keen to get rid of the scorching completely (albeit quite mild but I'm trying to do very light roasts so any tiny bit of scorching would seem particularly apparent). I haven't tried the timer mode yet, it'll probably help to make sure the starting agitation looks alright. Did a search for how an ideal fluidised bed looks like and wonder if we can replicate this on the kaffelogic:

https://www.youtube.com/watch?v=sBMnw6Wwzi0

Hi again

Thanks for link on video.

Ive used Damians D-Roast with a fan modification near the end to get under the power limitation. It is a very good profile, and like his reasoning behind it. Still not perfect for all beans that I have tried, but better than normal. For me it’s a good proof of concept, that the higher fan at the start works with the right weight of beans. Less burning/scorching.

According to Kaffelogic (Chris), the fan is supposed to slower on this roaster by design to “soak” up the heat so to speak, and something about the air flow not taking the heat away from the beans and get some momentum going heat wise. Something like that. It’s discussed in one of the videos for viewing down the bottom of this community support page, which is from one of the virtual cafe sessions.

Unfortunately with all the profiles pre D-Roast and core profiles just released I’ve always had a little bit of tipping, but more so the burnt/scorching which definitely causes issues with the taste/flavour. It will be interesting to see what the newer profiles are like. I had first crack happen at only 6 min 30 seconds on the 150-2000m Rest profile on a Guatemala Huehuetenango. Be interesting in a few days to see how it turns out.

Cheers

[nrdlnd]

@Geronimo
I have used the same profile 1200-1500 Rest as you and I have not had any problem with tipping. This profile has the highest preheat setting at 1200W of the core profiles. My not so long experience with the "Official" profiles with fan speeds at the start of 1470rpm hasn't given any problems with the movement of the beans or any tipping or scorching. I have used 100g batches and the environment temperature has been above 20 deg C. I have published a picture of this log in another thread before and the ambient temperature was about 23 deg C.

Kalledavarapura_1200-1500_Rest.png (59.51 KiB) Viewed 5941 times

I happen to have some roasted beans left of this roast and I can't see any signs of tipping or scorching and here is a picture of what's left. Edit: The white balance is not quite ok in the picture (too yellow) but I think there is possible to see that there are not many defects on the beans.

1200-1500_Rest.JPG (142.58 KiB) Viewed 5941 times

I haven't had much success with the extremely high fan speed profiles like D-Roast even with modified fan speeds and I can't really see the reason for these high fan speeds. I'm trying just now to get good roasts from Brazil beans for espresso and I have had most success with Steady&Dark II. The first roast was with the standard setting L=4.8. DTR around 25%. This roast became a little too dark for my taste (but no tipping!). I have then made two roasts where I have as an experiment raised the preheat to 1000W and with L=4.5 and 4.2 respectively. DTR around 24% and 22%. Still no tipping with the higher preheat setting and no warnings. Both roasts tasted very good. They are both medium dark. The last one should have been lighter but there were different beans (the last one was a lower altitude bean). Next time I may try L=4.3. For now these are my best roasts with Brazilian beans for espresso. I want to make a blend for espresso and I will probably stay with this profile for the Brazilians that I want to have as a base in the blend.

[Geronimo]

@Geronimo
I have used the same profile 1200-1500 Rest as you and I have not had any problem with tipping.

Hi

Excellent comment and results. Could be a simple thing that I have a faulty roaster. It is quite a bit cooler and have to roast outside as chaff goes everywhere, as the mesh doesn’t seal perfectly, and the plastic that the chaff collector sits on is slightly warped from the heat, and leaks around the bottom.

I won’t be roasting for a week or so but will try same profile again but with 100g rather than 120g, and see how it compares. I’ll try and pick a warmer part of the day.

Here is the last Brazil roast, note this is using 0-1200m Rest profile.

Photos actually look better than what they are, as also the white balance is not accurate as the paper I've written note on is actually pink, and the beans are darker than seen on screen, as phone has enhanced the shot to make it more bright and vibrant. I tried to use the grey carpet to act like a photographic grey card to get the white balance right, but was a big fail.

This is log curve for roast 2. I removed the two zone boosts, which I don't know why they would be even be in there for a generic profile. And goes against what Chris mentions in a video. I'd certainly understand if it was for a specific bean.

Brazil Cerrado 0-1200m Rest V1.0 boost zones removed.png (47.85 KiB) Viewed 5929 times

Above, Curve for roast 2

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Above, Roast 1: Brazil Cerrado, 120g, 0-1200m Rest, Roast Level 5.0, DTR 30%

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Above, Roast 1: End view of beans (randomly selected)

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Above, Roast 2: Brazil Cerrado, 120g, 0-1200m Rest, Roast Level 5.0, DTR 29%

IMG_5703.jpg (2.05 MiB) Viewed 5929 times

Above, Roast 2: End view of beans (randomly selected)

[nrdlnd]

@Geronimo: In your first log 0140 your ambient temperature was 16.75 deg C. My temperature was 22.75. I think that it looks like the roaster tries to compensate for the lower ambient temperature and that it may be a normal behavior. Was the movement of the beans ok? The bean I used was a 100g batch. The bean is fully washed and grown up to 1400m altitude. It could take this higher preheat of the 1200-1500 Rest. As I've understood from "the books" a natural processed lower altitude bean has a lower density and is easier to heat but may also be more sensitive to high heat in the beginning. My experiment with raising preheat with Brazilian beans and Steady&Dark II went well but could maybe have gone wrong. I might have got an as good or an even better result by only lowering L from the default 4.8 that in my opinion gave a too dark roast. This roaster is a fluid bed roaster and it should be possible to have a higher preheat without scorching the beans if only the movement of the beans is ok. I find this little roaster to be an excellent piece of engineering with some really smart programming algorithms!

[Wayne]

@Geronimo

Thank you for posting the pictures and the roast profile .. Please can you send me the log of your roast . The one that you roasted the cerado .

You should not get any form of tipping . you also stated that this Recommended end level was 5 .0 and 30 % dev .. The coffee here should be much darker at a level 5 .0 ..

Let me have a look at your roast log and see if I can pick up anything .

Question I have , Are the beans tumbling and moving in the 1st 30 seconds o the roast ? Should have a very consistent flow in the first 30 , This will prevent further tipping . We might need to help you recalibrate the roaster .

On the zone boost points . All the core profiles are designed to work with multiple coffees with minimum adjustment needed to get the best from them. The zones are added to keep the mean temp line on or above the profile line and in some cases offer the added boost needed to take the cracking bean further into 1st crack . By doing so , trying to reduce or even eliminate the dump and flick coffee can go through from huge release of exothermic energy.

Please feel free to remove and play as much as you want . That is what makes roasting so unique to the individual . On that uniqueness , HOW DID THE COFFEE TASTE .

[Wayne]

Hi @Geronimo

Took a look at the Log 140.

you are sitting on the lower end of the main voltage . 231 V . Is there a plug in the house we can get more out of ? Maybe plugged into the socket on a stove or closest to the main DV board ..

This could be the reasoning for the longer initial heat . Also the fact that there was a lower ambient temp . This is really a stretch in my opinion .

Also , Please could you confirm what coffee you were using in the roast .