New in roasting, how to understand the graph

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
Imihai
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Joined: 3 years ago

#1: Post by Imihai »

Hi everyone,

As many of you, I understood at one moment I have to go deeper with my hobby of just preparing coffee so I started to roast. From the beginning a very "dumb" roast (a strain net over the stove). Now I've upgraded myself with a fluid bed roaster from K-bopar (Smola BP-300). It is so cool and at the same time so many new doors opened with the new roaster.
I understand that each person has its own roasting profile and I should find mine, but I need some directions on how much time, RoR and other help.
Also I would like to understand the graph

Maybe it looks ugly, but it's my first roast, and I would like to understand it and to try to make it better.

Any help and any tips would be accepted.

Thanks!

pcofftenyo
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#2: Post by pcofftenyo »

The first thing would be to configure Artisan so that when you make heat and/or fan changes you can mark them.

That way we can determine what's causing the bean temp (blue roller coaster) to cycle so much.

Second, if your probes are moving in the roasting chamber you'll get inconsistent results.

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Rickpatbrown
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#3: Post by Rickpatbrown »

First thing is to get your charge right. How many grams of green did you put in? For drum roaster, about 75% of states capacity is about right.

You need to get your ROR curves under control for them to be useful. Either you made too big of changes, or your charge is too small and the roaster overpowers the charge.

It's also a really fast roast. Fluid bed should be faster, but not 4 minutes.

Pictures and description of the roaster controls will help. I'm having trouble finding info on the web

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MNate
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#4: Post by MNate »

This thread on using the FreshRoast, a common fluid bed roaster, might be helpful. Fresh Roast SR800 - 1/2 lb Air Roaster
In part it's helpful because as the thread goes you see people trying different approaches. So keep reading and trying. What works for one person/roaster/bean might not for another. And fluid beds do seem difficult to compare to drum roasters.

I'm far far from an expert. Just another normal person fairly new to roasting but, I think:
Bean Temp Rate of Rise (your deltaBT on your graph) is the main thing to look at. Big swings (roller coaster) isn't what you want, but I think it's kind of inevitable with fluid beds as you get used to them. But try to keep it within a range...
-from charge to when the beans yellow you can keep the rate pretty high (um, in Fahrenheit above 30degrees per minute, not sure what that might be in Celsius...)
-from yellow to first crack aim for it to stay in the 15-30 degrees Fahrenheit per minute
-and for the rest of your roast keep it under 15, but don't let it go negative.
Many people want that rate of rise to gradually go down throughout the whole roast.

The other thing I really pay attention to is the end temp I'm aiming for. This will likely NOT be the same as anyone else's because probe placement matters so much for the temp. You'll just have to try one batch at one final temp and another a bit higher and see what things are like. Compare their final state to a roast level guide, like this one: Sweet Maria's roast profile summary Oddly for me I want to drop the roast before all the cracks of first crack are done, even though that's not what good roasters would do but Otherwise it just gets a bad dark... yeah, I'm not a good roaster but you kind of just have to go with what you can do to make your roast as good as you can.

But yeah, pictures and more descriptions of everything would be helpful!

Imihai (original poster)
Posts: 5
Joined: 3 years ago

#5: Post by Imihai (original poster) »

pcofftenyo wrote:The first thing would be to configure Artisan so that when you make heat and/or fan changes you can mark ...
I'm afraid I cannot do these things (at least automatically) because the only input to my artisan thermometer are the two temperatures in the roaster.
But for my first try I used 60% of power for the first 2 minutes, and 80% of power for the last part. The fan power I didn't change for the entire roast.
Oh, and I used 100g of coffee beans, when the machine can roast 300

Imihai (original poster)
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#6: Post by Imihai (original poster) »

Rickpatbrown wrote:First thing is to get your charge right. How many grams of green did you put in?
I used 100grams

Rickpatbrown wrote: It's also a really fast roast. Fluid bed should be faster, but not 4 minutes.

Pictures and description of the roaster controls will help. I'm having trouble finding info on the web

I tried to see what the machine can do. After posting here I went to find some books about roasting and now I have some ideas, about RoR or deltaBT and also I understand why the time should be as it is.


Imihai (original poster)
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Joined: 3 years ago

#7: Post by Imihai (original poster) »

MNate wrote: But yeah, pictures and more descriptions of everything would be helpful!
You can see the photos in the answer above.


I have read some guides on how to roast and now I can understand a little on how to control things on the graph. I will use some time, but I can do it.

Thanks for the answer, it is what I was looking for

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MNate
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#8: Post by MNate »

Nice. You know... the reason we had to adjust the fan a lot on the Fresh Roast was, first, because the beans would blow out the top if we didn't, and second, less fan can actually deliver more heat to the beans, (which I still don't understand, really). But... if you can leave the fan on max and keep the beans churning (but not bouncing together in a big mass), I'd leave it on high.

Just for fun, try to just set it at one temp the whole roast and see how it goes. In theory that would deliver a declining rate of rise. If it's too quick of a roast then next time set it lower.

Also, we Fresh Roast people also have to manually enter the fan and heat levels in Artisan which we do just to keep a record. Here's how I did it: Artisan Setup without Input Devices

I bet you'll have good success!

Rickpatbrown
Posts: 461
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#9: Post by Rickpatbrown »

Imihai wrote:I'm afraid I cannot do these things (at least automatically) because the only input to my artisan thermometer are the two temperatures in the roaster.
But for my first try I used 60% of power for the first 2 minutes, and 80% of power for the last part. The fan power I didn't change for the entire roast.
Oh, and I used 100g of coffee beans, when the machine can roast 300

These are settings that you can congigure in Artisan. Its challenging to dig into all the setting (events, sliders, smoothing, etc), but its super worth it. Check out the Artissn documentation that CarefreeBuzzbuzz has put together. Very helpful

Imihai (original poster)
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#10: Post by Imihai (original poster) »

After reading some documentation about how to roast coffee and what are the approximate standards I've got a more stable roast



Also you can see on the graph my gradually increasing power of the roaster: starting with 50% and going up to 80%.

Now I found that my drying phase RoR can be a little higher, the second phase is acceptable and after the first Crack RoR is a little higher. So onmy next roast I'll try o keep the power at 75% and let it develop slower.

But thanks everyone for tips. At the moment I just practice with some beans that are not the best quality. When I'll learn to operate the roaster I will try with better beans andI will try to develop a nice taste.

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