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Am I missing most of the first crack?
sam-l
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Posted on 04/22/2023 9:20 PM
I have a FreshRoast SR540. I've been trying some of the roast protocols here and elsewhere. I keep the power medium and fan high for 4-5 minutes, temp is a bit over 300F, for drying. Then I'll turn the power up and gradually turn the fan down. If I don't turn the fan down almost all the way, the readout temp seems to never get above 400, and I assume the beans will never be hotter than that readout temp.

Once I have the fan almost all the way down, I can usually hear first crack starting between 7-9 minutes.

The problem is that I seem to only get a few scattered cracks. I've read that you should hear every bean crack, like popping popcorn. I don't know if I've ever heard that. So, what happens is, I'll hear the initial first cracks, I wait for a while, not sure if it's still "first crack", or if I'm in the development stage after first crack, and eventually I'll just stop the roast when the color looks correct.

This is the most recent one I did. I heard a few cracks at 7:40, definitely not all of them, I let it go until 10 minutes, at which point I was concerned it was getting too dark, so I stopped it. Haven't tasted it yet, but my recent roasts have been lacking flavor.

i.imgur.com/X3awfKZ.jpg

And just to prove that it's wasn't some temperature problem, the one before that I roasted pretty dark. I heard it crack some more as it was getting really dark, around 15 minutes, which one would think is *second* crack, except that it sounded more like first crack (loud popping) and also I didn't hear a thorough first crack, only a few scattered cracks.

i.imgur.com/Gn2PDHX.jpg
 
renatoa
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Posted on 04/23/2023 2:19 AM
Welcome !

A video to see the bubbles dance would help a lot.
Based on your figures, my guess is that your agitation is more energic than should be. I would aim for just a boiling, without lot of pops.
Lowering the fan allows you to roast faster, in the 6 minutes ballpark for FC.
Will also improve uniform heat transfer to more beans, compared to a chaotic dance where half of beans are in the air.
 
HarryDog
Top  #3 Print Post
Posted on 04/23/2023 10:15 AM
Hello Sam-I, Welcome and it will take some time to get a feel for roasting so don't be discouraged!

I do see some issues in the two roasts provided, controlling the bean movement will help clear up some of those roast defects as well and give you a more consistent roast. (Less Facing, Scorching & Chipping)

I don't have a fresh roast but have seen many videos, what is your Green charge weight? Lowering it might help the movement as well if needed? Note even a small change can make a difference.

I have also seen that the roast chamber does not lock into place on some units, not sure they have changed that?
You can rotate the chamber a bit to see if that will smooth out the bean movement or air flow as well. You might find a better spot you like.

I have also had beans that don't have a loud FC and will be tough to pick up on with the fan noise.
Edited by HarryDog on 04/23/2023 10:42 AM
 
renatoa
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Posted on 04/23/2023 11:04 AM
Rotating FC should not change anything, everything is circular and symmetrical on all axes.
RC, perforated plate, can take any position in the heater circular bay.
Of course, without lock in place, for small load, no chaff collector on top, and high airflow, the glass RC can be ejected, but this is an extreme case...
 
sam-l
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Posted on 04/23/2023 11:46 AM

Quote

HarryDog wrote:
I do see some issues in the two roasts provided, controlling the bean movement will help clear up some of those roast defects as well and give you a more consistent roast. (Less Facing, Scorching & Chipping)

I don't have a fresh roast but have seen many videos, what is your Green charge weight? Lowering it might help the movement as well if needed? Note even a small change can make a difference.

I have also seen that the roast chamber does not lock into place on some units, not sure they have changed that?
You can rotate the chamber a bit to see if that will smooth out the bean movement or air flow as well. You might find a better spot you like.

I have also had beans that don't have a loud FC and will be tough to pick up on with the fan noise.


What issues do you see with the first roast picture? The second was just a test to see if it would get dark.

Do I want more movement or less? I have been roasting a small batch size just to get more roasts in, but I'm starting to think it's too small, beans moving too much and not trapping enough heat.

Usually I will hear some very distinct cracks, but just a few, rather than the whole batch, so I don't think it's the bean. I have a variety pack of beans, but I ordered some 5lb bags so I can run some tests holding the bean constant.
 
sam-l
Top  #6 Print Post
Posted on 04/23/2023 11:48 AM

Quote

renatoa wrote:

Welcome !

A video to see the bubbles dance would help a lot.
Based on your figures, my guess is that your agitation is more energic than should be. I would aim for just a boiling, without lot of pops.
Lowering the fan allows you to roast faster, in the 6 minutes ballpark for FC.
Will also improve uniform heat transfer to more beans, compared to a chaotic dance where half of beans are in the air.


This is very possible, I have been roasting only about 65g at a time to have more roast attempts with the beans I have, but I think by changing the batch size I'm changing an important variable and making it harder on myself.
 
HarryDog
Top  #7 Print Post
Posted on 04/23/2023 1:18 PM

Quote

sam-l wrote:
What issues do you see with the first roast picture? The second was just a test to see if it would get dark.

Do I want more movement or less? I have been roasting a small batch size just to get more roasts in, but I'm starting to think it's too small, beans moving too much and not trapping enough heat.


Hello, first roast is facing and scorching. Not a lot but some. Second roast scorching and chipping, that's the round hole in the outside of the bean.

The beans are not moving evenly or enough on both roasts causing this uneven roasting. They need to move/rotate more. If they move but slide on the glass on one side it will face and scorch.

Sweet Marias has 130g as the sweet spot for charge load.
https://www.sweet..._sheet.pdf

A video would help.
Edited by HarryDog on 04/23/2023 1:25 PM
 
HarryDog
Top  #8 Print Post
Posted on 04/23/2023 1:24 PM

Quote

renatoa wrote:

Rotating FC should not change anything, everything is circular and symmetrical on all axes.
RC, perforated plate, can take any position in the heater circular bay.
Of course, without lock in place, for small load, no chaff collector on top, and high airflow, the glass RC can be ejected, but this is an extreme case...


Interesting, so the air pressure is perfectly even on all outside edges of the roast chamber?

I have seen a video on moving the chamber and it changing the bean movement, will look for that, I don't remember which version of the Freshroast roaster it was. This is a fine tune measure anyway, also an easy test to be done during the next roast to see if helpful or not.
 
renatoa
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Posted on 04/23/2023 1:35 PM
The heater unit is a very similar, but oversized version of a popcorn machine.
The main difference are the holes in the roast chamber bottom, versus the lateral slots of a popcorn RC, so a lot less vortex, and a lot more lift.
 
HarryDog
Top  #10 Print Post
Posted on 04/23/2023 1:35 PM
So this video used 130g at full fan, I don't think the beans are moving enough and they sit on the inside shoulder (In the roast chamber) maybe 125g so they don't sit in this area going around the chamber facing the same direction.
Edited by HarryDog on 04/23/2023 2:02 PM
 
HarryDog
Top  #11 Print Post
Posted on 04/23/2023 1:46 PM

Quote

renatoa wrote:

The heater unit is a very similar, but oversized version of a popcorn machine.
The main difference are the holes in the roast chamber bottom, versus the lateral slots of a popcorn RC, so a lot less vortex, and a lot more lift.


So the popper heaters I have taken apart have slots in the heater material to let the air in and 4 areas that block the air flow (For stability of the heater I assume), this causes channels in the air flow.

You have probably used or worked on these roasters so would have a better understanding of the air flow.

This video goes over some profiles for your roaster.
Edited by HarryDog on 04/23/2023 2:48 PM
 
renatoa
Top  #12 Print Post
Posted on 04/24/2023 1:58 AM
There are also two versions of the bottom holes pattern, that can change the beans movement.
The most recent is honeycomb, with a central dead zone, probably to favor circulation.
~~~
renatoa attached the following image:
image_2023-04-24_095821201.png
 
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