Ikawa Home thermal performance - Page 5

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
nicolai

#41: Post by nicolai »

GDM528 wrote:I need to drink down all the experiments I've been running, before I sacrifice more for science. :)

A few other fan experiments I'm thinking about:
1) Effect of fan with beans in the chamber
2) Spinning bean mass 'altitude' versus fan speed
3) Effect of fan speed on the exothermic phase, e.g. 'flick and crash'
:D I know the feeling, I love roasting and observing how things work out, but my friend brought over about 3 kg's of roasted beans from his last training, so trying to get through those - In the mean time no roasting for me...

As for the experiments it could also be good to investigate dose and fanspeed - I.e. bigger dose, higher fanspeed? And can it be the reason why some people are facing slightly more uneven roasts at higher dose?

As for point 3: I think flick and crash is almost irrelevant in an airbed: First of all thermal mass of roaster is extremely small and let us assume 1st crack does create a drop in temp the applied energy would very quickly be able to recover.
Even in conventional drum roasters it is still discussed if a flick or crash has any significant impact to flavor - Although that there is a high level of emphasis in many of the "bibles" of coffee roasting.

Let me know if you find some teardown information on the machine - I will be ordering a Yoctopuce thermocouple and the electronics are so small that I should be able to find a smart place to mount the controller inside the enclosure of the roaster.

mgrayson
Supporter ♡

#42: Post by mgrayson »

Overlay of a data dump from a roast on the Pro100 vs. Gary's Home roast in post #23.

Well, I screwed up a bit entering the intake temperature profile. But the biggest difference is that the Pro asks you to drop the beans after preheating, where the Home seems to like preheating with the beans. Or, at least, that's what I was doing and looks like was done here. Still! The temperature curves are very close! And I think the bean thermocouple is a perfect analog of the Pro's exhaust numbers.



I've also noticed that the Pro's fan speed is normally slower than the Home's I used the Home fan speeds here, so that may have been part of the mismatch. ¯\_(ツ)_/¯

Matt

nicolai

#43: Post by nicolai » replying to mgrayson »

Hi Matt.

Thanks for doing the graph.
Where is the exhaust probe located? Mind snapping a pic?

mgrayson
Supporter ♡

#44: Post by mgrayson » replying to nicolai »



Matt

nicolai

#45: Post by nicolai » replying to mgrayson »

Thanks a lot!

ira
Team HB

#46: Post by ira »

I have been raising the fan speed on one profile to see if I can get 100 gm batches with better bean movement without losing any beans. It's a balancing act for sure and while the editor gives me control, I find small adjustments difficult, wish I could just type in numbers. Maybe when my own iPad shows up this week, I'll just sit and play with the app and figure it out, now I have to steal my wife's to experiment.

Ira

GDM528 (original poster)

#47: Post by GDM528 (original poster) »

mgrayson wrote:Overlay of a data dump from a roast on the Pro100 vs. Gary's Home roast in post #23.

Well, I screwed up a bit entering the intake temperature profile. But the biggest difference is that the Pro asks you to drop the beans after preheating, where the Home seems to like preheating with the beans. Or, at least, that's what I was doing and looks like was done here. Still! The temperature curves are very close! And I think the bean thermocouple is a perfect analog of the Pro's exhaust numbers.

image

I've also noticed that the Pro's fan speed is normally slower than the Home's I used the Home fan speeds here, so that may have been part of the mismatch. ¯\_(ツ)_/¯

Matt
Nice overlay! This bodes well for recipe sharing across the user community.

GDM528 (original poster)

#48: Post by GDM528 (original poster) »

mgrayson wrote:image

Matt
Wow. To paraphrase Crocodile Dundee (first movie): "now that's a thermocouple". Is that the only thermocouple in the chamber?

mgrayson
Supporter ♡

#49: Post by mgrayson » replying to GDM528 »

Yep.

GDM528 (original poster)

#50: Post by GDM528 (original poster) »

mgrayson wrote: But the biggest difference is that the Pro asks you to drop the beans after preheating, where the Home seems to like preheating with the beans.
For what it's worth, I've observed my Ikawa Home (100g) switches from pre-heat to roast at a chamber temperature of about 45C after an overshoot to about 50C for just a few seconds. Seems like that may be largely inconsequential to the final roast outcome. Dropping the beans upfront saves the user from having to hover over the machine for 30 seconds or so.