Pro -> Home profile conversion

roasting

#1

I read previous threads discussing about how to mimic the pro, how to convert the pro profile, and I tried to compare two exact same Ikawa Gesha profiles on Pro app (inlet and exhuast temp based).
ikawa_inlet_exhaust

and it shows quite predictable difference in inlet and exhaust (evironmental?) temp,
which is,
+46c at 201c inlet,
+44c at 210~220c,
+40c at 230~235c,
+38~39c at 237~241c.

I know that bean characteristics and humidity can have effect on this difference, but these small differences can happen all the time, bean by bean, day by day.

I wanted to know applying these inlet to exhaust temp differences and converting some pro profiles to home can be a good starting point, or totally meaningless attempt because it’s just so different for every bean.

I read that some of the members already installed thermo sensors to get exhaust or environmental temp data, and want to hear if the temp difference is way different on other profiles or beans.

How does the preheat and charging temp exactly work on Pro?
Does it preheat until the temp goes up to the temp set at 0:00, and notify the user to drop the beans?
If that’s the case, how long does it maintain at that temp for preheat? if it’s 60s~90s or so, we can mimic this with inlet and drop the beans then?


#2

In an effort to find the truth and not necessarily be right, I’ll throw my hat in the ring.

So far as I see it, the air temp because of such a large amount of volume and velocity will not differ much in readings from inlet to exhaust given that (regardless of size of the bean) the same velocity and volume of air passes through the beans. Meaning that using the same profile with slight tweaks to the air speed to achieve the same speed, the temp reading from inlet to exhaust will not be significantly different. That isn’t to say how the beans are effected by the heat remains the same. So if I have a small Kenya bean and a large Pacamara the profile will have to be different because the beans will not react the same given the same temp/fan profile.

Because we aren’t measuring the bean temp we are measuring the air temp the amount of air is masking precise readings of bean temp.


#3

Hmm… then why is the same profile for inlet temp and exhaust temp significantly different on Pro?

But isnt Pro only measuring air temp too? Just two different air, inlet and in the cahmber? (Exhaust)


#4

But it isn’t really radically different every time, this it is consistent. It is reliably the same difference of average 43C with the range being 38C-46C from inlet to exhaust. My intuition when I wrote way back when, when looking at “Pro” profiles, and trying to mimic them on the Home roaster that throughout the roast the the variation was from about 100F-60F based on color changes and cracks and finishing temps.

I don’t think looking at the Pro profiles are a good starting point. They are made by people either roasting for a competition or sampling both are dependent on brew, ratio, and possibly even brew temp. And will require just as much testing and theorizing if you were to plug in any random profile, look at the color changes, smell the beans periodically as they roast, note first crack (it’s duration) and possibly when second crack is. Tasting the coffee in the cupping will give you an idea if yellow took to long (dry/baked), too short (acidic vague), development too short and too slow (vegetal), or if you over shot the roast (Burnt, acrid, ashy). Personally I think taking one profile and roasting it many ways to see how it changed that bean has taught me a lot more and gave me more information so now, if I wanted to use a Pro profile, I know how to adjust it. I have written a lot about these kinds of things too, they are in the backlogs if you wish to visit them.

Though, my way isn’t the only way. I don’t write this to deter anyone from doing whatever they want. It is just my experience and thoughts which I don’t mind are taken up or completely ignored.


#5

AFAIK the Pro warms up to pt1 at 1min and automatically drops the beans.
The Pro was changed after the Home came out to also run via inlet profiles whilst still retaining the exhaust option.
I haven’t looked for a long time but was only one Pro inlet profile I could find - may well be more now of course. I modelled a Costa Rica geisha on it and it turned out well. But so did a number of other Home profiles.
I don’t think that there is anything magical about the Pro profiles as @deven.patel411 points out some are very likely not optimal in their intention as sample roasts.
Enjoy your experiments!


#6

@deven.patel411 and @stephen.pickering21
Thank you so much for your experience and thoughts. Well yeah I didn’t really expect something magical(?) from the profiles but was interesting to see most of them roast really short (around 5 mins) and charging hot. Wondered what it would bring, but again as Deven mentioned, yeah maybe it"s natural to roast very light for competition, thus they are usually really short time.
Thank you always for sharing your experience!


#7

I think experimenting is great fun and certainly would not discourage it.
Looking back I was roasting around 5m30 inc 1min heatup before manually dropping and had mixed results. Some really good ones but I was brewing next day.
I think short roasts can be great as next day roasts but maybe don’t age as well? It may be they pick up again after a couple of weeks or longer.

These days I tend to aim around 9 to 10 days resting and roast both for filter and espresso.


#8

It is many years since I tried the IKAWA PRO (v2) And as I recall you press a preheat button and when ready you are instructed to drop.
From this IKAWA PRO (v3) profile, the roast was started when the inlet temperature was measuring 175°C.
Yellow=Inlet Red=Exhaust


#9

That is really interesting to look at that graph with inlet and exhaust. It looks like they stay very evenly spaced the entire time. Also no noticable blips on exhaust for FC or anything. Does the crash and flick that Scott Rao talks about not apply to fluid bed roasting?


#10

Wow thanks for the graphs. This tells a lot.

  • This was a taken after the preheat right?
  • it seems like we need the initial spike to match the exhaust temp, even with the preheat. I guess we pretty much need that initial temp spike to mimic any Pro profiles, or without it seems like we will go through a pretty slow drying phase.

Another thing I noticed is that the inlet to exhaust temp difference is pretty steady, at around 40c?


#11

I tried the Tim Wendelboe profile converted to Home,
with preheating at 197c for 1 min, and dropping the beans and ending at 240c~241,
with two different beans,

  1. Ecuador La Papaya Typica Mejorado Natural (which heat up pretty quick)
    and,
  2. Colombia Pink Bourbon

The 1) finished right after the 1st crack started,
and for 2) I couldn’t even hear the first crack.

I’m curious if this is intended or my beans just need more heat.
The 1) had great flavors and smelled sweet from whole beans, but it was pretty acidic after V60 drip.
I wonder how they brew these super lightly roasted coffee.

It was light enough to jam my Niche Zero grinder.


#12

I think they let them rest for weeks or even a month. I have actually been experimenting with ways to shorten that as I don’t have the patience to wait 2 weeks or longer to test. I have tried longer times of open air rest and even pre grinding 12 or 24 hours in advance. Both really help with releasing gas and taking away grassiness, but flavor is flat. I have found myself gravitating towards more medium roast, even though that is not my preference, just to use quicker. If i find something that works I will pass along! I am starting to wonder how these light roasts I buy are good within 1-2 days of being roasted. I am starting to question the validity of those dates, they must let that stuff sit awhile and just stamp a recent date on it.


#13

For me, 1) wasn’t that grassy. It had nice hints of fruits but just too acidic. Maybe I just needed to grind finer and pour much slower…

What are the roasteries you buy light roasted beans? Just curious what are the best examples of light roast.

Just a random guess, but they might cool down the beans really really slowly? So that it doesnt go darker, but still in a pretty warm environment for a longer time so that they gas out much quicker?


#14

Interesting thought on the cooldown, that makes logical sense though for sure. Maybe worth testing quicker cooldown once I get machine back.

I have a localish roaster that does great light roasts called ross street roasting. He does fluid bed, so feel like its something comparable to what we can do on ikawa, and I can find some of the green beans he uses on la bodega to see if I can match what he does. If he has any Ethiopian guji left, that is amazing. My wife can never taste anything in coffee, but that one she text me at work and said why did you put blueberries in my coffee this morning lol. Probably the best of the best for me though would be kuma and heart, just more expensive and no ability to get their green coffee to try roasting.


#15

Forgot to mention too good idea on the grind size. I recently started using a clever dripper in order to take out variables from comparing my roasts, but it knocks out a lot of acidity to brew that style too, so you could try that too.


#16

This has also happened to me with lighter roasts, I haven’t tried the slow feeding that James Hoffman is making popular on the YouTube.


#17

I have been doing a lot of reading lately on home barista forum on roasting. Someone there made a good point about trying emulate pro profiles with home machine. If the pro model is able to follow an ET line, it would have to make constant adjustments to intake air based on origin, moisture, ambient temp etc. The pro model is actually really cool when you think about what it has to do to make that happen. That being said, i think it is futile to try to match pro profiles.


#18

I can’t agree that trying to copy a Pro profile is futile per se, but if someone doesn’t know how to adjust profiles in general and given different beans inherent nature and the purpose (brew method) then it would be futile. But if you see a profile and you know the range the transitions and markers take place on the Home, then looking at Pro profile for a Pacamara or Geisha then it would be a nice starting point as a general marker to start with that and then make adjustments based on your bean and purpose, et cetera.


#19

Good points, are you crunchybean over on HB forum?


#20

A twenty character answer: yes