Real time colour tracking

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

#1: Post by stoned_survival »


I have recently moved from an Aillio bullet to a Probat 05 series 2 roaster. I missed the controls I had on the bullet so I have upgraded the Probat with extra thermocouples( ET and BT 3mm probes) as well as a differential pressure sensor. I went the Phidget route. However, my experience as well as Marten Munchows(coffee mind) research both point towards "roast colour" being the most definitive predictor of roast consistency. Since I am roasting commercially consistency is key for me.

I wanted to ask the community here if there are any sensors/equipment to track colour change during the roast in real time effectively. I know there is ColourTrack RealTime. However, at the minute that is prohibitively expensive for me. Probat has its own new solution to this end however I have not been able to get any information about it yet. I have emailed them to ask for more details .

I have done my research online and real time colour tracking in the food industry is definitely not unheard-of. There are 2 possible windows to "look" at the beans - through the little "glass window" in the faceplate or through replacing the trier with some kind of probe. Look forward to hearing your thoughts regarding this. All commercial as well as DIY solutions welcome ! :D


User avatar

#2: Post by MaKoMo »

Did you read this: Understanding Roast Color

stoned_survival (original poster)

#3: Post by stoned_survival (original poster) »

Wow! All the knowledge about measuring colour in one place - amazing. I learnt a lot from that article. However, I feel like I am after something slightly different. I would like a tracking number to know when to pop out the beans from the roaster. Do you also know if the Tonino guys also explored a real-time measurement?
In my simplistic mind the question is this: Imagine putting alight inside the roaster, and a camera that only perceives "intensity" of colour even on a monochromatic scale. As the beans get darker , the intensity is higher.
Is this SO complicated in 2023 ? :o :D

Thanks a lot!


#4: Post by DenisSabou »

What you are asking already exists for commercial purposes not home roasting. ... r-control/

And there is also roest p3000 that has a camera to take color info and bean shape while roasting. But you are looking at it from a wrong angle, the inside color is not the same as outside color, lighter roasts have a bigger difference in-out while darker roaster have a less difference. The proportion between in-out might not be linear, specially after crack when the beans open the moisture is released so the heat can go inside, there are many variables to get to the to the drop.

Taste is related to color in about 80%, but we are talking about the inside color not the outside. The outside is not as relevant, specially now when you have one million processed beans and blends within the same single origin.

stoned_survival (original poster)

#5: Post by stoned_survival (original poster) »

OK. I understand what you are saying . However, I believe both Probat and Roest are implementing this with the mindset that for a given bean and a given profile, consistency will depend on achieving the same outside colour each time - Does that hold true in your opinion?

I also understand that this exists in the "commercial" roasting world. However, companies like Probat are asking for an arm and a leg for this. I wrote to them to ask if I could incorporate this tech into my roaster and they replied back saying that the price of colour tracking alone is more than the entire shop roaster itself, so no point!! I have had similar experiences with Probat before. Their upgrade VFD kit for fan speed control is unnecessarily high priced. I looked up the components that they used to add this functionality to my roaster and the cost of the components used are not even a fifth of what i was charged. They are not proprietary components and can be purchased on the internet.

In my (simplistic) opinion, this sensor/functionality should be possible at a reasonable pice point.


#6: Post by DenisSabou »

So then come with a project on how to implement it if it's so easy. You'll have to write a software to take a milion measurements, take out the odd ones (low and highs) and then average the values and display them at a decent refresh rate. Good luck with implementing it.

We barely got infrared temp sensors that are not influenced by bean mass/weight in some roasters and you want a camera to tell you the color. :D

That's like wanting a car that goes 500mph, but our roads are made for 100mph something like that. Yes the camera color would be a nice feature, but you can roast good coffee without. Also getting a new roaster dropping the beans at asked color doesn't mean great coffee, the exterior as I said can be roasted to X agtron the but taste can be really bad.

stoned_survival (original poster)

#7: Post by stoned_survival (original poster) »

I think you are mistaking my optimism for frivolousness :D :D
I don't mean to say that its an easy thing to do - just trying to find ways to do it.


User avatar

#8: Post by MaKoMo »

stoned_survival wrote:Is this SO complicated in 2023 ?
Did physics changed recently?

stoned_survival (original poster)

#9: Post by stoned_survival (original poster) »

Did physics changed recently?
Everyday! :lol:

User avatar
Supporter ♡

#10: Post by lassepavoni »

The Raspberry Pi Foundation just released a global shutter camera module, which might be adequate for this use case. Still a long way to go from there, though. ... er-camera/
Regards, Lasse
LMWDP #744