My first roasts on the Huky

[dynamiteid]

OK, I finally got everything set up and did my first roasts last night. I definitely have much to learn on controlling the profile. I am moving to the Huky after roasting with a popcorn popper for 6 months and then a Genecafe for 3 years. I was able to get some really good coffees off of the Gene. In fact, I tied for first in last year's Homebarista roasting competition for espresso. However, I just couldn't get the control I needed to take my roasts to the next level. I think the Huky paired with a Phidget and Artisan will be the tools that allow me to do that.

I will post a separate topic on my unpacking and set-up. I also will forego details about my first roast as this was really just targeted to understanding how everything worked and testing out the Phidget/artisan set-up. The only thing I will note is that when using the Phidget, the BT is the first input, followed by ET, and then MET. I had the ET and BT switched. Also, 400g generates a lot more smoke than 226g!!! I had to go get some ducting to direct the exhaust outside before doing the second roast.

On to the second roast:

I tried to follow Kfir's suggestions:
Preheat the roaster to 220-230c (ET), no airflow. turn around point usually at 1:35.
Drop the beans, keep the heat at 50% until BT=150c, no airflow (you can leave the "chimney" open).
At 150c BT (~3.5-4 minutes), increase the heat to 75% and use very low airflow or 6-7 sec of high airflow every minute.
at the start of FC (~198c BT, ~8-9 minutes) give a strong pulse of airflow for few seconds and reduce the heat to 50% till the end.

As you can see by my log, my TP dipped too low in temp, and subsequent drying phase took too long. I guess I need to pre-heat longer to get my ET higher before drop. I was rushed to get started. I think this would increase the TP temp and shorten the drying phase. Also, I need to slow things down when approaching FC. I turned the air up too much trying to adjust the exhaust. The roast didn't develop long enough and started SC before I knew it.

Please give me your advice. What should my Delta-BT targets be for each phase? I hear people mention a steady decreasing ROR. What values are people targeting?

I am loving the Huky!!!!!

[edtbjon]

That is good results for a first roast. (Well, at least the graph looks very good for a first session...)
First, you don't have to worry about if the TP is "too low" at 90C. That's OK, but you have to press on a bit more with the heat from the beginning. (That's really a good thing, which I'll come to later...) I do suspect that the roaster had cooled off a bit as MET was lower than ET and BT. That made the beans cool a bit more than what you planned for and also made the roast slower in the beginning.
I take it you may be using some kind of dimmer or Variac to control the exhaust fan (like most of us seem to do). Also, you seem to have set up Artisan to record these values (manually in artisan while you roast). Else follow the instructions in that doc. on the Artisan website about Artisan with the HotTop. Once you have the sliders (or possibly event buttons) going, it's easier to refer to the graph and see what you did with the controls (fan and gas).
Anyhow, the Delta-BT is that curve which goes up just after TP. Once it reaches its top a "perfect" delta-bt curve would be a "straight" line in about the angle in between 2.45 and 5.30 in your roast. (The fact that is isn't "straight" there is mostly due to a resolution setting in Artisan.) I.e. if you had kept adjusting gas and fan to keep that line on it's current slant, it would have been a very good example of a "steadily declining RoR". I got to give it to you, that you are not that far from it.
About slowing down at FC, I add quite some air just before FC and then throttle the gas quite a bit some 20-30 sec into FC. FC is tricky as the beans "releases heat" for a while there.

Maybe not a perfect roast (given the graph), but I guess that after say 6-7 days of rest, I wouldn't spit that coffee out.

[SusanJoM]

Else follow the instructions in that doc. on the Artisan website about Artisan with the HotTop. Once you have the sliders (or possibly event buttons) going, it's easier to refer to the graph and see what you did with the controls (fan and gas).

There are some screen shots of Artisan button set-ups in a PDF file that is in the Dowloads section of the forum.  The actual settings in the document are probably not optimal, but it at least shows how they get configured....ifn that works for you.

[dynamiteid]

Thanks for the advice. I did two more roasts. Here is the last one I did. It was a 400g batch of a Yemen natural. I was able to control the declining ROR better. The beans look and smell great. Can't wait to try them in a few days. This is going to be a fun learning curve.

[Johnny4lsu]

You appear to be doing an awesome job right out of the gate

[SusanJoM]

I'm curious as to why MET is lower than ET and BT when you charge.
(Not that it shouldn't be, but it never is on my graphs.)

Is your drum maybe not turning during the warm up?