First Series of Roasts w New Huky

[e.p.alx]

So, finally got my Huky allll set up last week and got a 5lb bag of pretty cheap beans from a Bodhi just in time to roast this past weekend... !!!

First off I "seasoned"-lightly by gathering about 250g of leftovers, stinkers, suspected quakers etc. and roasting them half way to charcoal. They got all greased up and it was great, everything went well and smoked out the back yard.
Next I did 3 separate roasts of the washed Mexican bourban beans from Bodhi.

The first batch 250g I burnt up.. was overwhelmed while writing in temps (no artisan yet), checking notes and modifying flame and air and pulled them out later than I intended. They actually came out looking like FC+ but really just tasted like a slow roasted Firestone; burt rubber and acid undertones..
2nd batch 30 min later or so, 300g charge, actually came out decent! Pulled at about 11min, solid fullcity roast, certainly could have been better but no bad flavors this time at least.
One more roast the following day came out like a C+ only totally dry and flavorless.. Kind of disgusting actually, like a full batch of quakers. Funny because I thought my 2nd roast had been my worst and this last one seemed to have the most control but I'm guessing I just slow roasted them to death in the drying phase..?
Anyway, it was fun and felt like quite a steep learning curve coming from my popperyII (surprise..), but I'm just trying to get a better idea of what to do better/ what parameters to focus in on more from here. I know the second roast easily came out best but looking at my sheets its hard to really ascertain why exactly, so any feedback would be much appreciated.
Thanks yall.. 

-e

ps. please excuse the sloppy notes..

[edtbjon]

Congratulations! You're doing good! These roasts are definitely in the ballpark. Getting started is an adventure and you seem to have gotten through it in "one piece".

Well first, it takes a few days for the coffee to mature (but I recon you knew that...). Give the third roast a few days more for a second chance.
While I do understand your choice of 250g charges, which is a rather small charge weight, they are a bit tricky to control. It's a bit like driving a car with only on/off instead of a throttle with a decent throw to it. My idea of using smaller charges was that I'd be able to do more roasts while learning, but I found it expensive, as the main experience was that the roaster is a bit hard to control. Roasting 400g to full pounds will make the whole experience much more "stable".
Another thing I note with your roasts is that the turning point (TP) is a bit high. This has (at least) two side effects, first you risk scorching. Second, the roast is harder to control from there, as (in my experience) a high TP just makes me trying to break the speed of the roast without stalling.

[hankua]

200c is too high a charge temp. for 1/2lb, at least with the solid drum. Since the second roast came out OK, I'd stick with that profile and tweak the RD phase (1st crack to finish). At the beginning of 1C cut the heat back to the minimum setting and see what happens. Air can still be on low, low-medium, or medium; depending on how the setting affects the ROR (rate of bean temp. rise) If the BT stops increasing (stalling) the settings were too agressive, conversely if the BT shoots up crazy the setting were also too agressive.

The Huky stove can reach 4kPa and your only in the .5-1.5kPa; also the BT probe might not be as accurate. Keeping an eye on the ET temps is a good idea and try to get it down near your intended drop temp. at the end. BT can only reach the environmental temperature inside the drum.

[e.p.alx]

Wow, thanks a lot for the replies guys, it's taken me a couple days and reading up to better understand both your suggestions here and some of the larger concepts of how to operate.. But at least it feels like the train's on the track

Hankua, I was actually charging at about 220c for these roasts (BT i believe.. didn't take a good enough note of that however), this was based on Kuanho's guidelines for a 250g charge. I figured it high myself based on some posts here but I figured his guideline might be a good place to start.
Going to try a roast tonight w a charge temp <200c and see where it takes me.

One factor I've found particularly elusive is how to maintain a good control of ET without mismanaging BT. It's actually to the point after those last roasts that I began to just ignore ET because it seemed to behave so erratically (just a result of low bean mass maybe?).
What isn't recorded at all on those sheets however, because i don't have enough hands or multitasking skills, is the fan speed changes. They varied quite a bit on each roast but always started out off and eventually went maybe 80-90% for last few minutes (thus the constant ET BT cross late in each roast, i presume). But I'm still trying to understand what role that fan plays here and even more so to what degree the ET is effected by it and how to use that information.
So for now my attention remains strongest on BT but I look forward to hearing what you guys have to say about that approach. It does seem the strangest thing here how similar the BT curves are in each roast compared to ET curves and yet how different the end results came to be.
Curious indeed..

[edtbjon]

On the matter of ET, I've been roasting with the Huky for some 20 months now and I'm just in the beginning of even paying any attention to the ET while roasting. (While what's really happening is that I "control" ET by seeing what's happening with the BT probe...) The main use of ET (and MET) have so far been as an indicator for having the roaster properly preheated and "in balance" before I start a roast. There is good information around about how to use the ET probe. Susan linked an article written by Rob Hoos which I think is just about the best info around on the subject. But it does take some digesting...

[e.p.alx]

Thanks Jon, I did check out the Rob Hoos article, still digesting as you suggest. Really liked his explanation of RoR and keeping a consistent exhaust temp in order to force the BT to meet it, I'm just not really sure yet about how to keep the ET that high or consistent, as any use of my fan quickly begins to draw it down.

Also, when it arrived I taped my fan up quite a bit to create a very strong seal and maximize efficiency there, wondering now if that's proving to be less helpful than initially expected as the lowest setting still introduces significant temp drop to my ET.

On the positive side, last night's roast went great! Finally outperformed my air popper !!
Went with a slightly larger charge (305g) and lower charge temp (just about 200c i believe). Very sweet this morning with a nice medium level acidity. Some strawberry/ stonefruit flavors showing, light cacao dusting and cedar notes. Very pleased; I was beginning to blame the cheap beans for my woes (popper usually gives me a consistently good roast but even it didn't handle these very well). I'll post my sheet soon, usb adapter for my probes showed up today tho so I'll finally have artisan running soon. Good news all abounds!!

[e.p.alx]

Ok, so 3 roasts later annnnnnd.... I'm getting there.

Last roast mentioned here did come out very very nice, but the past two after that using Artisan didn't turn out quite as good and while tonight's does seem like it will be better than those, things ended up moving too fast near the end, couldn't get the heat down and so I don't it's going to be quite as nice.

First here's the good chart..
(ok, not sure how to place it here actually but it's the one on paper)
-Those are my heat notes jotted sporadically at the bottom, 305g charge (making this my control for the time being), fan only came on for those big dips in ET (don't think I had my variable speed control yet, so all or nothing here).
Pulled at 12min, just at the end of 1C, City+ territory and wow, just hit my lucky numbers on this one I guess cuz i promptly lost it for the following two ..

I tried to emulate this roast in my past several roasts to different degrees but with pretty limited success.. Most difficult thing for me to get my head around has been heat. I started at just 1KpA on the good roast and slowly worked my way up to 2 by the end. Trying temps this low since hasn't worked out so well though. I need to be able to get good med/dark profiles so I'm trying to up the heat early on and get it to gradually taper for a nice curve (seems like the most consistent sign of a good roast), but seems like I always end up chasing the heat early on and by the end I lose control.

Today's roast was better, at least i think (3rd pic), started at 2kPa, quickly moved to 3, down to .3 after 1C, but tragically it was too late and had already became a runaway train..
I'm sure I'm letting the temps just get too high in general, I'm not sure what pull temps should be for varying roast levels but I've had a tendency to loose track of BT a bit at the end, worrying about varying my heat, fan and valve, and checking trier, watching time, etc.

Hunt for the proper curve is elusive but I feel like I'm getting there..
Thinking next roast I'll shoot up to 3kPa at TP and bring it way down by maybe the 6:30 mark, and start cranking the fan to really try to flatten out the trajectory.
If you've got any other suggestions holler at me! I'm all ears..

[e.p.alx]

Also if anyone knows how to get deltaBT and deltaET logged, pls let me know; it seems to be tracking it live while Artisan is running but can't seem to get it to show up on the graph.

thanks

[Agrajag]

Hey mate, have you seen Gregr's Guide to Achieving a Rao Curve? My first roasts have been following this and I've been getting pretty good results right off the bat. With lower charge amounts you have to be more careful especially bringing the temp down, but I've found that guide will give you a good starting point.

For deltaBT/ET, see Tools -> Extras -> and check the checkboxes under Curves.

[e.p.alx]

Wow, can't believe I didn't see this earlier.. This is exactly what I've been looking for, thanks Agrajag!
I must have seen Kenneroast's perforated slow motor guide a while back and forgot about it (I do a lot of early am inebriated binging on here.. ), cause it seems pretty familiar. Either way this is a huge help.
Yeah leveling off the temp seems to be the biggest issue for me right now, but I like the suggestions here.

Thanks for the Artisan help as well Agrajag, I'll try that out when I get home!