mathof wrote:Of course, it was made for the original 50g Home Roaster, so it may need some adjusting or keeping to a 50g load. Let us know how you get on.

First attempt with Sweet Maria's Polar Expressso (mandatory misspelling) ended just at the first pop of Second Crack. Perfect! I used 75g, and the fan was a bit slow for a while - I wasn't sure the beans were mixing well. But the funnel shape opened for the last four minutes, and I think it was even in the end.

I'll report on taste after I let it rest as long as I can stand to, but it looks great. Thanks again!

It was from post #199 above. Matt Hoffman kindly gave us a link to his legacy profile.

[quote="mathof"]Here is a recipe for "Full City 2nd crack" from my legacy collection. Maybe clicking on it, or pasting it into your browser, will open it in your IoS app


Thank you mathof! Yes, it does load into the iOS app, and is fully editable within the free version of the iOS app. The temperature profile is interesting - I would call it 'relentless': a steady 9 minute ramp from 187C to 289C, with the last five minutes above 225C. I imagine all beans would crack (twice!) under that kind of pressure. Screenshot below is from the free iOS app. The editor layout is kinda sloppy in the iOS app, but I can read-out the exact temps in the Android version.

RyanP wrote:Around a dozen roasts in and my machine went on the fritz yesterday morning. Stopped connecting to the app. Purple status light. I contacted Ikawa and my unit sent them a "motor fault" error code. I have to send it back to them and they are going to replace it with a new unit. Good customer service so far. Quick response, replacing the unit, sending me a tracking label and scheduling a dhl pickup for Monday. But, I'm definitely feeling a bit wary now of the purchase, especially considering warranty is only for 1 year. Hopefully just a fluke...

RyanP, do you know how Ikawa was able to obtain an error code if your app was no longer connecting? The Bluetooth connection to your phone should be the only contact the machine has with the outside world...

Next chapter in my quest for a true dark roast on the Ikawa Home:
.
What the iOS app sez is a dark roast, is really only a City roast. The temperature setpoints (as viewed in the Android app) are easily high enough to hit 2C, yet their Dark +++ only hits 1C for a couple minutes before cooling down.

So I taped a thermocouple inside the roast chamber, with the bead right in the path of the spinning beans:



Then I created a profile that would set and hold a couple key temperatures long enough to get stable readings. I ran both with and without beans in the chamber:



First off, I salute Ikawa's PID tuning - impressive! 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. One bit of good news, is adding beans only delays the response by about 30 seconds, so I don't have to sacrifice any more beans for science.

It appears that Ikawa's Dark +++ recipe doesn't quite put enough energy into the beans to reach Full City, and simply extending the development time would only produce a 'baked' city roast. If Ikawa had scaled up their recipe setpoints by just 3% I'd be a happy camper.

Ikawa's smart enough to know exactly what they're doing and why, so was there some sort of bad outcome with ever-so-slightly higher setpoints that would lead Ikawa to leave the dark-roast aficionados at the altar?

Thanks, Gary. Very useful data! When I measured exhaust temperature, I thought the difference was due to beans absorbing the heat.

If I had to guess at Ikawa's motives, I'd say that they wanted to keep Full City away from the folks who just want to push some buttons (that's me, BTW) and not design their own roast profiles. The former are more likely to be upset at a burnt roast or litigate after a fire. Perhaps part of the point of charging for the advanced editor is a "You obviously knew what you were doing and took the risk upon yourself" defense. The extra revenue doesn't hurt either, I suppose.

Their stated reason (somewhere in their labyrinthine website) is that folks want lighter roasts these days, or something similarly vague. Or I'm imagining it. I'm probably being too cynical. But now that I have a Full City curve on my phone, I'm much less annoyed about it.

I have noticed that +++ at medium or medium-dark makes for a simply duller roast. ¯\_(ツ)_/¯