HELP -- I can not hear any cracks

[green beans]

To give everyone some background I recently started roasting on a propane YM2, Costa Rica beans. I am having difficulty getting the beans to develop while roasting.

Here is an example: I roast 2 pounds and I drop them in at 420 degrees

-the temperature goes down to about 355 and steadily rises to about 390 at 9 minutes.

-at this time the beans are still looking very light and the heat continues to climb up to about 460 at 18 minutes

-i take the beans out even though they are not looking too dark but i do not think they should roast for too much longer time wise. I roasted one batch until it was looking dark (still not oily) and it took almost 30 minutes and tasted burnt.

I do not know a lot about roasting I am the first to admit that but I am trying to figure it out. Where is my major malfunction? I have not heard a single crack 1st or 2nd. The beans are always really light in color and seem to darken in splotches when it they do darken.


Any guidance is hugely appreciated.

[ElPugDiablo]

Did you test the accuracy of your temperature probe? The quick and dirty check is to stick it in ice water and it should read 32F, then stick it in boiling water, and it should read 212F.

[green beans]

Great thought ElPugDiablo it had not even occurred to me that the probe may need to be calibrated or adjusted.

There was one batch where I kept the temperature very high (never went under 400). The beans looked good but were totally baked/burnt to taste so that could mean that the temperature is mostly accurate.

[Davec]

it's a bit odd, you seem to be using quite a high drop temperature....I used to drop into a 25kg commercial probat at a substantially lower temperature than that!

Then the recovery of temperature also seems a tad slow and it drops a lot considering how high your drop temp is?? you also seem to be achieving quite high temperatures and ones at which you should definitely hear 1st and second crack.

yet you say the beans are either uneven or burnt.

Just a guess as I don't know the roaster....but I would be looking at airflow! if your airflow is not controllable, then remove the blower and check it, also check the cyclone and the stack for obstructions, sharp bends, facing into wind??...I say this because it sounds like somehow your not getting enough airflow (and hence convective heat through the roaster).

[ElPugDiablo]

To give everyone some background I recently started roasting on a propane YM2, Costa Rica beans. I am having difficulty getting the beans to develop while roasting.

Here is an example: I roast 2 pounds and I drop them in at 420 degrees

-the temperature goes down to about 355 and steadily rises to about 390 at 9 minutes.

-at this time the beans are still looking very light and the heat continues to climb up to about 460 at 18 minutes

-i take the beans out even though they are not looking too dark but i do not think they should roast for too much longer time wise. I roasted one batch until it was looking dark (still not oily) and it took almost 30 minutes and tasted burnt.

I do not know a lot about roasting I am the first to admit that but I am trying to figure it out. Where is my major malfunction? I have not heard a single crack 1st or 2nd. The beans are always really light in color and seem to darken in splotches when it they do darken.


Any guidance is hugely appreciated.

What temperature is it measuring? Sounded like it is an atmospheric temperature reading not a bean temperature reading.

[green beans]

Thanks Davec, I wondered about airflow but was not sure how it is controlled. I know how to turn the air to the cooling bin on and off but not air around the drum.


There is a bean probe ElPugDiablo going straight into the roasting drum. I have not tested the probe yet for temperature reading.

[Davec]

On the roaster I used there was a little wheel on the outlet tube from the drum. It may be that your airflow is not controllable, if so then it might be worth thinking about a blockage or if it's an old roaster, mabye the blower needs cleaning.

It's just what you describe is pretty much what you might get on a roaster trying to do most of it's heating via conduction from the drum rather than hot gases, especially the burnt taste and scorching together with the long long roast times.

Is the roaster new or old, hows the chaff clearance from the drum (do the beans come out very chaffy)?

[topher]

have you thought of doing a full batch? Try doing a full 5 pounds of coffee? Try that and see if you can hear anything then.

[Davec]

have you thought of doing a full batch? Try doing a full 5 pounds of coffee? Try that and see if you can hear anything then.

Whoops, just caught that Topher, I thought he was doing full batches!

[green beans]

I do have that control for the burner flame, a manual knob on the control panel. I do adjust it but I will be the first to admit my biggest problem probably is me being new to roasting.


I have done about 3 pounds but never 5 I figured I would try to figure things out with a smaller amount. Is it possible that I may hear cracks doing a full batch (5 lbs.) roasting the same way I have been smaller batcher??