1200m Rest L2.4 vs K-Logic L2.4

[Wayne]

Good day Sam

Thank you so much for the pictures and the logs . These are invaluable to better understand if it is indeed the KL , coffee or any other factors .

On the pictures . In true Santos fashion , you see both lighter and darker - even slight oil development on the beans . This mottled appearance is standard with santos . I know you made mention of removing a good bit of the tipping . I don't see any more and no scorching of coffee - Common divot in the side of the bean . The amount of tipping and scorching would generally be a lot more in the batch .

I have had a look at your logs . and compared them to mine . Everything looks good on both your logs from a travel and adaption to the log . On the 0-1200 REST log , the mean temp line fluctuates immediately from the start all the way to 1st crack . The control system is working hard to bring the coffee under control and trying to get the temp on or as close to the profile . I do not believe this is the cause of the issue .
On the Kaffelogic Classic profile , the coffee mean temp followed the profile beautifully without bumps and dips and flicks .

However , with my Santos on the 0-1200 REST , the mean temp had the same look and result that your santos had on the Classic profile . Smooth on the profile . Attached below .

As we know that Santos is a blended origin with different altitude and varying density , I believe that your coffee , although santos , is different from the santos I have and it is simply reacting to the 0-1200 REST profile differently .

Santos is , in my experience , an easy coffee to roast but does not always give you the uniform colour . especially at lighter roast profiles .

If the coffee tastes good , in the Kaffelogic Classic or any other profile . Why not use it and make it your standard ?

On the Fan profiles , the Kaffelogic Classic and the 0-1200 RESO profiles are the same . So I don't believe this is an issue . I have roasted El Salvador and other brazils on the profile with my same result . If you feel like experimenting , maybe adjust the start of the 0-1200 REST profile higher . See if you get a better result .

Regards

Wayne

[Wayne]

Hi Sam

This is excellent . Maybe try the 120 g batch . This might make all the difference .

Thank you G .. I hope you are well ? How is the roasting going ? Any new coffees ?

[nrdlnd]

Hi Sam, try a 120gm batch and see how it goes. I recall someone saying here that smaller batches can sometimes cause the beans just to spin, not necessarily bubble, with smaller amounts under certain conditions.
Newbie here myself, but I would imagine the beans not bubbling up and around would mean that some beans more than others a) stay closer to the heat source, and b) in contact with the chamber wall.

Purely theoretical, but the softer start of the 1200m profile might be causing that. There is a chance a larger batch might see the air force the beans to move differently.

Whats it's worth. In my test above with the 0-1200 Rest I used batches of 100g with my beans and I had no scorching. I checked the movement of the beans and it looked OK.

[Sam]

Thank you for all the responses and suggestions.

I think I will default to K-L for Brazil Santos.

I have used the core profiles with other beans and had similar issues with tipping and scorching. Both Peru Organic RFA and Ethiopian Shakisso had similar issues.

Btw, is anyone measuring green bean density? If so, how would one go about measuring density and then applying the measurements to selection of the core profiles.

Sam

[Geronimo]

I have used the core profiles with other beans and had similar issues with tipping and scorching. Both Peru Organic RFA and Ethiopian Shakisso had similar issues.

Btw, is anyone measuring green bean density? If so, how would one go about measuring density and then applying the measurements to selection of the core profiles.

Sam

Hi Sam

I've put aside for the time being my Peru Organic RFA as I have similar issues.

With respect to density, Wolf College of Coffee, have some useful Youtube videos on all things coffee. Here is the link to vid on measuring bean density.

https://youtu.be/_LODgPOQRPA

Cheers

[Sam]

Hi All,

Geronimo, thank you for the link. Makes for interesting viewing.

The Peru Organic RFA made an excellent sweet espresso. I have a little remaining and will try again with K-L Classic.

Is measuring bean density a way forward to better understanding the core profiles?

I have weighed my beans for a fixed volume but haven't translated this to the core profiles.

Sam

[Steve]

Here some measured observations of the 2 profiles in question.

Coffee is a Brazil Pulped natural Andressa 2018 / 2019
800 - 1200m
Grade: NY2/3 SSGC
Caturra / Bourbon
Milk chocolate, caramel, big body

Chris did a good job with the Classic profile, it is pretty close to getting the basic roasting Environment Temp principles right for an air roaster. Understandably when creating a catch all profile compromises have to be made. Still it is fairly user friendly profile across a wide range of tastes and is a great replacement for stale supermarket coffee. The Classic at 2.4 is substantially more and better developed than Rest1200 at 2.4. Classic = 15.8% weight loss, Rest1200 = 15%


Rest1200 takes far too long to reach appropriate ET, under developing the roast from the very start, this likely causes the outer layers of seed to over dry and the insides never get done. Eventually the temp picks up, it stalls out around 240 - 242 after first crack never really gets going, I counted 6 individual cracks from 9:30 (233ET) until near drop around 11:00 (241ET). Because of the over drying from the slow start the beans are far more susceptible to damage when the temp finally gets hot enough, coupled with being stuck at very low agitation in the latter parts of the roast for a much longer amount of time compared to the Classic = charred and still under done in the centre.

Contrary to popular belief low density / dry beans actually require more heat at the start of a roast.
Look at the picture of the 2nd crack roast I did with fixed high power profile using India elephant hills 1000m - 1300masl. Beautiful colour, not tipping or scorching to be seen because it ramps to an appropriate environment temp very quickly while the beans still have moisture to spare. https://kaffelogic.com/community/viewto ... =240#p1545

Classic2.4.JPG (73.59 KiB) Viewed 5444 times

Classic.jpg (1.62 MiB) Viewed 5444 times

ClassicET.JPG (79.53 KiB) Viewed 5444 times

Rest1200.jpg (1.65 MiB) Viewed 5444 times

2.4Rest1200.JPG (83.13 KiB) Viewed 5444 times

Rest1200ET.JPG (72.11 KiB) Viewed 5444 times

[Sam]

Hi Steve,

Thank you for the clear explanation.

This is exactly what I've been experiencing with the Rest1200 on my low altitude beans.

I agree the K-L profile is a safe bet with most beans.

Sam

[nrdlnd]

Here some measured observations of the 2 profiles in question.
----
Rest1200 takes far too long to reach appropriate ET, under developing the roast from the very start, this likely causes the outer layers of seed to over dry and the insides never get done. Eventually the temp picks up, it stalls out around 240 - 242 after first crack never really gets going, I counted 6 individual cracks from 9:30 (233ET) until near drop around 11:00 (241ET). Because of the over drying from the slow start the beans are far more susceptible to damage when the temp finally gets hot enough, coupled with being stuck at very low agitation in the latter parts of the roast for a much longer amount of time compared to the Classic = charred and still under done in the centre.

I'm sorry but I can't see any stalls on the 0-1200 Rest. Please advice me how to see it!

I have made roasts with the same bean Brazil Doce Diamantina (good/medium quality Cerrado pulped natural 2019).

1. 0-1200 Rest at L=3.0. Difficult to hear 1C but it was around 10 min and DTR around 18-20%. Evenly roasted without apparent defects. Medium dark (City+) No scorching and only a small tendency to tipping. I use to cut the beans to look inside and it wasn't completely even colour inside.

2. 0-1200 with a merged fan profile from Steady&Dark II at L=3.0. A little lighter roast. Evenly roasted without defects. I did cut the bean and it had a very even colour inside. Very easy to hear a distinct 1C that came earlier.

3. Classic at default L=3.3. My intention was to stop the roast at an appropriate DTR but I couldn't hear 1C. Darker than the other two (Full City). No defects but a little more apparent tipping probably without concequencies for taste. I cut the bean and it looks inside the same as 0-1200 Rest. Roast no 2 had the most even roast inside.

The 0-1200 Rest and the Classic looks very similar but the Classic is of cource roasted darker. The 0-1200 with another fan profile is more evenly roasted inside.

I don't know yet how they will taste. This is just my observations of the roasts and I don't have the same knowledge and experience as Steve to evaluate them. For me the 0-1200 Rest looks good and is about similar to the Classic profile. Decisive is of course the taste!

[Steve]

Here some measured observations of the 2 profiles in question.
----
Rest1200 takes far too long to reach appropriate ET, under developing the roast from the very start, this likely causes the outer layers of seed to over dry and the insides never get done. Eventually the temp picks up, it stalls out around 240 - 242 after first crack never really gets going, I counted 6 individual cracks from 9:30 (233ET) until near drop around 11:00 (241ET). Because of the over drying from the slow start the beans are far more susceptible to damage when the temp finally gets hot enough, coupled with being stuck at very low agitation in the latter parts of the roast for a much longer amount of time compared to the Classic = charred and still under done in the centre.

I'm sorry but I can't see any stalls on the 0-1200 Rest. Please advice me how to see it!

Roasted any other way this coffee cracks quite well for a Brazil PN. First crack languished for about 2:30 and nothing good ever comes from this even if one was to disregard all temp readings.

Compare the overall shape of the two ET curves.
Classic holds a very even nearly straight line angled upwards all the way through. This is what I expect to see on a 100g air roaster which has zero mass to fall back on if the bean mass drops in temp.
The rest1200 is more of a gentle downwards curve.

If you are enjoying the coffee produced then thats great / dont worry about it.