Large mass-loss & flat roasts out of a Loring air roaster

[essquared]

Hi everyone, new to the forum here. We've switched over to a 15kg Loring and are having issues dialling in baselines.

Still getting accustomed to it - have to say its a very efficient machine, however after a couple of trial runs the coffee's are coming out very flat, so 0 acidity, and getting very large moisture loss by the look of the weight going in and going out, and just the way they grind - too soluble. The interior is much darker than the exterior even though I am roasting to a light degree.

I suspect that there's too much energy and heat going in too early in the roast, and the beans don't have ample time to dry properly, and/or the charge is too high. Since there is no drum, it makes it more difficult to tell since there wouldn't be any sign of scorching if thats the case.

The roasts are not long, 10lb batches, 12 minutes for the first couple, and I tightened them up for the next after I saw the results to 10minutes. Has anyone encountered this, or can say that it would be the charge/turn around point? Below is one of our runs.

Charge @ 380

1:00			245
2:00			310
3:00			337
4:00			352
5:00			364
6:00			373
7:00			382
8:00			390
9:00			393 FC**
10:00			397
11:00			408

Thanks - any input would be appreciated.

 

[peterjschmidt]

What percentage of weight loss are you seeing?

Based on where you're seeing 1C, I'd say you're correct about rushing the roast in the drying phase; 4min to 352* is very fast.

The strange thing is that a quick roast like this in an air roaster is producing a flat, non-bright result. <scratches head>

 

[essquared]

As high as 20%.

That's why I'm confused as well. If its not the dry time and too much energy in that period, I was thinking possibly too little airflow.

 

[peterjschmidt]

If you can increase the airflow, that would be a good place to start. Or conversely, drop the batch size by a pound.

 

[JumpinJakJava]

Having never used an air roster like the Loring or Sivetz, I do not know what control you have to manipulate the roasts.
Peter mentioned airflow control increase, is that possible? I am assuming temp control is your major control function on an air roaster.
Is that correct? If so, I would start there. Noticing your roast log between 1 min and 2 min. there is a 65* increase. That is really fast.
Then 27* over the next min. also a little fast at that point. From there the temps look good.
So you are losing moisture too quickly. That is why the internal bean is too dark.
Lengthen the drying time with less heat. You stated " I tightened them up", I would start with
lengthening the roast time beyond 12 min. To around 15 min. and beyond, and cup results.
Here are a couple of links that may be of some help:

Roast Profile Translation in Typica - Coffee Roasting - YouTube

Roasters Guild Forum ? View topic - Delta Point

 

[essquared]

Thank you for the input guys - Im going to give it another shot monday, run each roast slightly differently with the temps specifically in the beginning.

 

[DirtyDave]

Are you still having problems with your roast?
The Loring is not an air roaster, nor does it do "normal time" roasts well.
Closer to 20 (or more!) minutes is de rigeur for the Loring.
The flexibility of the control system should allow you to overcome most shortcomings.
You'll always be left with the recycling of roast chamber effluent back onto your load, can't bypass that.
Don't attempt to install one in a AQMD conrolled environment, they will not pass.
Good luck.

 

[ccooper]

DirtyDave, I'm seriously considering buying a Loring, and hope you can answer a couple of questions.
1) Do you have an explanation for why longer roast times seem to be required?
2) The Bay Area, where I am as well, is certainly AQMD-controlled. But I am given to understand that these roasters will easily pass the permitting process. Can you clarify your statement with further details?

 

[DirtyDave]

Been busy roastin'
If you try to execute traditional drum roaster profiles, since you have no conductive effect, it takes allot longer.
If you are in Oakland, call the AQMD, and determine the acceptable level of NOX effluent.
They won't pass this aspect of the test.
There are different standards for stack measurements in different counties in California.
Typical.
The Loring IS NOT AN AIR ROASTER.
It barely qualifies as a hybrid.
Although it has many interesting mechanical solutions, I've never had an acceptable cup out of this device.
I can't tell you what to buy, I gave up on commercially available roasters 20 years ago.

 

[ccooper]

Well, I guess we'll see. I bought a Loring. It will be about 4 weeks before it is running.
We did some test roasts on this machine. Not as good yet as our current product, but that's by simply using our current drum profile, an 11-12 minute roast.
I will be surprised if we have difficulty with AQMD. Yes, I'm in Oakland, but a friend recently installed one next door in Berkeley without trouble. Also, a coffee roaster right next to me operates without even an afterburner!

 

[DirtyDave]

All you need is one complaint.............

 

[brewroland]

The flatness on Loring machines are common problems, you could end up roasting "raw"