Rob Hoos/Loring Free Roasting Defects Seminar - Page 2

#11: Post by **drgary** » May 6th, 2021, 5:38 pm

I didn't participate in Discord but thoroughly enjoyed the Zoom presentation and took lots of notes. His answer to my chat question about too much convection was very helpful in suggesting that I roasted too fast. Here was my thread on that. The coffee was awful:

How does high airflow strip flavor from the bean?

It was fun to hear TomC and Luca (if he was our Team HB member) participate.

May 6th, 2021, 5:39 pm

The recording should be posted on the Loring YouTube channel: http://www.youtube.com/c/Smartroaster/videos.

#13: Post by **TomC** » May 6th, 2021, 5:54 pm

Great stuff! And thank you Chris for sharing the link!

May 8th, 2021, 5:37 pm

The video has been posted.

May 11th, 2021, 2:12 am

I've been away for a while and seemed to have missed some good discussions lol. I'll be watching this tonight while most of you are asleep

Thanks for the heads up and posting the video afterwards. Much appreciated.

#16: Post by **luca** » May 11th, 2021, 6:03 am

drgary wrote:It was fun to hear TomC and Luca (if he was our Team HB member) participate.

Yes, sorry, that was me. Whilst I was interested in the answer, I was also conscious that Loring had put the whole event on and, to their credit, none of it was especially Loring focussed, so I wanted to ask some Loring focussed questions. It's a strange beast, in that they call it a drum roaster, and it looks like a drum roaster, but it really seems to have quite different heating.

#17: Post by **Almico** » May 11th, 2021, 10:19 am

My concern with the Loring is the link between heat and airflow. You cannot raise or lower each separately. If you want more heat, you automatically have to turn up the airflow and visa-versa. This reverses the typical drum operating practice of high heat/low airflow to start a roast and low heat/higher air to end it. Add to that the inability to lower the heat below 20% makes roasting on a Loring significantly different than roasting on a proper drum.

#18: Post by **EddyQ** » May 11th, 2021, 11:33 am

Overall, I enjoyed the talk. I couldn't agree more about how scorching ruins flavor. I like how defects have been identified and terminology defined.

That said, I don't 100% agree that scorching can only be done with a hot drum. I have scorched beans with my DIY heat gun roaster years ago. But a half decent commercially available roaster should be much better than my heat gun approach, so we likely can bet scorching is generally due to a hot drum.

IMO all Lorings are drum roasters. But the heat delivery is very different than the traditional drum roaster and their drum is relatively thin. Until someone goes out and measures incoming air temperature and drum temperatures of a Loring, I am going to believe they are very similar. True heat delivery of a Loring is still to be determined.

I heard the convection/condition ratio mentioned again as possibly 70%/30% for drum roasters. This I have proved to be completely incorrect for my drum roaster (and I believe all drum roasters) during development phase. Since this ratio does in fact change throughout the roast, the ratio isn't very useful without talking about the phase it occurred. Perhaps when one compares the maximum convection heating of one roaster to another, this ratio may be meaningful. But show me some measurements instead of some far out there claim of general performance.

IMO, the solid, smooth heat delivery of a heavy drum could buy us more stable heat during development (relative to a more convection roaster). Does this result in better flavors? I surely don't know.

#19: Post by **luca** » May 12th, 2021, 4:44 am

For anyone wondering, Lorings are quite different from regular drum roasters:
1. They have a stationary drum, not a rotating drum. The stationary drum has rotating paddles in it.
2. They only have one burner, which is offset from the roasting chamber and heats air. The burner provides very high heat, for both afterburner and roasting.
3. The hot air is filtered and recirculated through the closed system
4. The stationary drum has no direct heating; it's all air.

The advantage of this is that it's incredibly energy efficient. The figures that people claim are that lorings use something like 1/3 of the gas for the same amount of coffee compared with a traditional drum.

So that's the background.

I don't really know much about lorings, but I do know:
1. They are the "weapon of choice" for a number of highly regarded roasters that roast light.
2. TW thought that, compared with the classic Probat UG series, they make it easier to get better development at lighter roast colours.
3. I've been trying to use the kaffelogic fully fluid bed air roaster and I've found it very difficult to get good results. I suspect that the changing airflow and the changing temperature are part of what makes it very difficult to control.

I suspect that probe temperature readings sort of mean different things at different airflows, but I don't know. I'd have hoped that with the loring the decoupling of airflow from agitation (by having paddles) would make it easier to control, but I don't know how you adjust temp. If you still have to adjust airflow to adjust temp, then maybe that's not the case. It'd be interesting to know how that works on a sivetz (sounds like you don't get much control) or another fluid bed commercial roaster like a Neuhaus Neotec. It'd also be interesting to know how it works on the Roest, given that there's no recirculation, so you probably can adjust temperature without changing airflow.

Christopher Feran had a very interesting blog post about accounting for the effect of the drum to create a loring profile that performs like a drum roaster:

https://christopherferan.com/2021/04/21 ... -roasting/

What all of this means for getting good coffee, I don't know. I've had good and bad coffee from lorings and more traditional drums. Plus I gather other drums are somewhat on a spectrum eg. the probat P series I gather has some sort of hot air feed and the new probat sample roaster I gather uses hot air.

#20: Post by **Almico** » May 12th, 2021, 9:51 am

luca wrote:1. They are the "weapon of choice" for a number of highly regarded roasters that roast light.

I would have thought that too. But when I attended an "Ask the Roaster" seminar at Coffee Fest a couple of years ago, all 4 roasters on the panel that roast at the Pulley Collective in Brooklyn, NY (where they have a Loring and a UG15) said they prefer dark coffees on the Loring and light on the Probat.