RyanP wrote:I'm not sure. An error message did first show up on my phone right when the machine disconnected. So perhaps that error message contains a code or some more detailed info that is automatically forwarded to ikawa? Really not sure..

Glad that you will get a new machine and IKAWA is backing up the warranty. Also kind of interesting that IKAWA the company is getting data of the roaster (which we may or may not have access too) and it being sent automatically.

I'm tryin to understand how an air roaster works in comparison to a drum. Anyone out there want to help with my education?

GDM528 wrote:But the big takeaway for me, is the 40 degree drop between the setpoint and actual - yikes. I haven't tested it yet, but I wouldn't be surprised if the fan speed affects the temperature drop.

A large temperature drop is to be expected. The inlet probe is under the metal louvre, which undoubtedly absorbs some heat, and far enough away from your thermocouple for there to be a considerable drop in temperature.

There's a similar difference between inlet and exhaust temperature at the start of a roast on my Ikawa Pro V3, and it increases quite a bit by the end of the roast, in the following case to about 100F:



The profile is based on the Espresso Roast I profile in the Ikawa Pro library. I dropped early to get a Light roast. The increase in the temperature difference is probably due to a combination of increasing inlet temperature and decreasing fan speed.

FWIW, I used to see a similar large difference between MET, which is a rough measure of inlet temperature, and BT in my Quest M3. Lots of distance and metal/airflow between those two probes.

It's not clear to me from this thread which profile(s) and batch size(s) aren't able to get to dark roast level and/or second crack, but it seems to me that a 50g profile with a larger batch size could easily result in not enough heat being applied for darker roasts.

When I was considering the Pro V3 versus the Pro 100, I pointed out to the sales rep that most of the profiles in the Pro library were developed on Pro V3 roasters and asked whether 50g profiles would work on the Pro 100. I was told they work "consistently" on the Pro 100 (whatever that means), though Pro 100 profiles won't work well on a Pro V3 (now Pro 50.) I don't recall whether I asked if the batch size had to be reduced -- i.e., reduce it to 50g when using a 50g profile, but I vaguely recall the rep saying that the Pro 100 is designed for 100g batches. Although I knew the Pro app would let me adjust profiles to compensate for any differences between the two models, I was looking for more of a "plug-and-play" solution, and the uncertainty over profile compatibility was one of several reasons I went with the Pro V3.

I wouldn't be surprised if Ikawa's profiles for the Home 100 shy away from darker roasts to avoid burning, fires, liability, etc. I think if you're going to use legacy Home profiles and you want a darker roast, you need the editing capability. And you should monitor the roaster so you can stop the roast if there's any sign of burning.

I don't know how you're judging color level, but I wouldn't eyeball it. Often surface color can be deceiving. Best to use a color meter. I use the EspressoVision RoastVision, and it works quite well.

BTW, the thermocouple taped to the roast chamber is a great idea (as long as the tape is rated for high temperatures!)

Wanted to better understand what the ROR curves look like on the provided profiles.
Using the Guatemala Blue Ayarza beans and provided profile, I was able to connect to Artisan via a Perfect Prime 3 mm K type thermocouple and Phidgets.
Used Ikawa recommended Medium-Dark++ profile.
Weight loss and Dev % is higher than I generally like, but would have been easy to stop the roast earlier. Just wanted to see what happened.
The Perfect Prime isn't the best thermocouple, but at least gives you an idea what is going on.
Not sure I can explain the first couple minutes.
Seems like the ROR is rising way too high if that is really measuring BT and not air temp at that point.
Thoughts on the first 2-3 minutes of this curve?

Looks like a good, heat resistant Kapton tape, that's what I used to tape down my thermocouple in my Behmor for almost 10 years without issue.

Peppersass wrote: It's not clear to me from this thread which profile(s) and batch size(s) aren't able to get to dark roast level and/or second crack, but it seems to me that a 50g profile with a larger batch size could easily result in not enough heat being applied for darker roasts.

In my roasting to date, no batch size (usually 50g-75g, once 100g) with any Ikawa supplied profile has passed "medium", as defined by grinding some Klatch medium roast and looking at the ground coffee side by side. The legacy Full City Second Crack profile posted above yields ground coffee matching Nossa Familia's Theodoro's Italian roast (4 out of 5 flames). I am fully aware of the unscientific nature of this information, but it is as good as I can do.

Taking an existing profile and moving the slider to Dark++ seems to suggest extremely long development times. Dark+++ just looks silly. Granted, FC often happens 30-40 seconds after the graph suggest it should, so Development may not be quite so extended. I have not experimented with Dark+, though I expect it to be my goto for medium roasts.

yakster wrote:Looks like a good, heat resistant Kapton tape, that's what I used to tape down my thermocouple in my Behmor for almost 10 years without issue.

Bingo! That Kapton tape is rated to about 400C. I started with a conventional Type-K thermocouple and stripped off all the asbestos cladding, 'cause "asbestos roast" doesn't sound very appealing. Also needed to fit under the glass cover without interrupting the seal. relaminated the wires onto a couple strips of narrow and wider Kapton so it could hug the side of the chamber without messing with the trajectory of the spinning beans. the approximately 1cm extension of the wire off the wall of the chamber kicks some of the beans out of their orbit, just like the ramp that's already in there. Actually seems to improve bean mixing, so I may keep it installed longer term. The location also gives me an inference-free readout of air the beans are experiencing.

Peppersass wrote:A large temperature drop is to be expected. The inlet probe is under the metal louvre, which undoubtedly absorbs some heat, and far enough away from your thermocouple for there to be a considerable drop in temperature.

There's a similar difference between inlet and exhaust temperature at the start of a roast on my Ikawa Pro V3, and it increases quite a bit by the end of the roast, in the following case to about 100F:

Is there a teardown of the Ikawa out there somewhere? I had been speculating the temperature control feedback loop might work off the temperature of the heater (rather than the airflow) to minimize the loop delay (helps control stability). However, it would improve accuracy if the temp was taken from the actual airflow, but I have a hard time reconciling such a large drop given the aggressive airflow rates.

Going outside my pay grade: given the first law of thermodynamics, changes in volume/pressure will change temperature. So perhaps the pressure drop and volume expansion going into the roast chamber might account for the temperature drop. This is why I wanted to put the tip of the thermocouple right in the same air as the beans.

My first attempt at going over to the Dark Side:

Started with Ikawa's Mexican Huatusco recipe. My reasoning is that it was developed by people who's full-time job is to do that sort of thing, using beans they didn't have to pay for themselves.

Opened the recipe using the Android version of the Ikawa app, which still allows editing sans subscription. The edits can also be made in the free iOS app, but the graphic for the exact temperature readout is obscured (intentionally?). I then bumped up just the last three temperature setpoints about 10-15 degrees C, and added another 30 seconds to reach exactly 8 minutes for the roast 'cause I like integer numbers.

I don't have a color analyzer, so apologies for a measly photo (yeah, I know I misspelled "Huratasco"):



I'm spitballing the roast levels, but what I'm calling City + finished first crack and had roasted quietly for at least a full minute before cooling. What I'm calling Full City just started 2C as cooling kicked in, the beans have a subtle shine that's not apparent in the photo, and a few of the beans show signs of cracked shells and cratering.

Below are the recipes I used to chase my dark demons. Batch size was limited to 60 grams so the beans could keep up with the profile, and yield exactly five batches from the 300g bag Ikawa gave me. Disclaimer: I'm unqualified, never know what I'm doing, and these recipes could very well ruin your prized beans and/or burn your house down.

https://share.ikawa.support/profile_hom ... uZWkxYgEw

https://share.ikawa.support/profile_hom ... uZWkxYgEw

I'm much happier with the color and aroma of the darker roasts. Apologies for the sacrilege inflicted on single-origin beans.

I consider this a magic moment in my nooby, first-time Ikawa-user experience, given the precision with which the machine bent to my will. I asked it to to go up 10 degrees, and it went up... 10 degrees. Just the behavior needed when trying to thread the needle between baking and burning.

sosha wrote:I'm tryin to understand how an air roaster works in comparison to a drum. Anyone out there want to help with my education?

I've found Sweet Marias to have useful introductory content, like:
https://library.sweetmarias.com/how-to- ... aster-faq/

My physics-y explanation is air roasting uses convective heat transfer, whereas a drum roaster uses conductive and radiative heat transfer. Kinda like the difference between cooking chicken wings in a hot air 'fryer' versus on a hot skillet.