BC-600 roaster review - Page 2

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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FotonDrv
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#11: Post by FotonDrv »

One of the things I like is that the BT Probe is NOT mounted on the moving dump door but sits in the face plate in a fixed position. No bending of the wiring every time the door is opened.

I am sure there are other things that I might spot in person and really am looking forward to more information about the roaster.
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brettpavia
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#12: Post by brettpavia »

Thanks for posting about these machines, as this is the first I have heard of them. For some reason the North Roasrter that Mill City is sell must have just come up in my search result more often.

Still have many questions about these BC and Sedona machines, but I do find them to be a good option

Again, thanks for posting this.
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slickrock
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#13: Post by slickrock »

FotonDrv wrote:One of the things I like is that the BT Probe is NOT mounted on the moving dump door but sits in the face plate in a fixed position. No bending of the wiring every time the door is opened.
However, if that probe placement is for BT location, it will largely miss the bean mass at small batch sizes and/or at low drum speeds. Also, an ET probe will be needed as well... its location up for grabs.
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FotonDrv
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#14: Post by FotonDrv replying to slickrock »

You certainly are correct. The probe placement is very important; do you think the BT probe is a bit to close to center to be real effective?

The ET appears to be measured from the exhaust temps and not in the hot air that encircles the drum exterior above the burners. On the otherhand that is all relative and would be peculiar to this roaster.
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keno (original poster)
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#15: Post by keno (original poster) »

I've now done about 10 batches on the BC-600 and thought it's time to post a little bit about my initial roasting experience with the roaster. I can already tell that the learning curve will be much quicker than when I first got my Huky 500 given all of that prior experience, but it is still quite a different machine in a lot of respects and it will definitely take more time to really get comfortable with it.

The very first two batches I did were only 170 grams (half my standard batch size) just to test it out. With this small batch size I had a hard time controlling the roast, which I think was due to two factors: (1) the machine is definitely more responsive than the Huky, and (2) the bean probe placement (about a half inch above the top of the door) is a little high for a 170 gram batch size. As a result any change in air or heat was immediately picked up by the probe, meaning that it was not really situated in the bean mass.

However, my typical batch size is 340 grams and when I switched to this batch size I noticed a steady reliable bean temp reading. My next four roasts (a couple done with my friend LDT) were just intended to get a handle on the new machine. We've all read on HB that every roaster is different and nothing teaches you that lesson like switching to a new roaster. At first, for lack of knowing what else to do, I found myself trying to use this roaster as if it was my old Huky 500. The result was a roast that was way too fast - finishing in about 7 minutes! But each additional roast provided a little more feedback and helped me to figure out my landmarks and navigation for the BC-600. By landmarks I mean things that we can reliably observe during the roast - like turnaround, yellow, and first crack. On my Huky turnaround was around 1:30 after about a 150F temp drop, but on the BC-600 turnaround was closer to 1:00 with only about a 100F drop. On the Huky I'd generally get to yellow at 320F, while I noticed I reached yellow at 310F on the BC-600. And, finally, I would generally hit first crack at 390F on the Huky but got there 20F lower on the BC-600 (at 370F). Consequently, I realized that my drop temps would need to be shifted back by about 20F to get a comparable roast. This was a really good lesson in how much roaster design and thermometry can impact temperature readings. And it made me realize that one needs to be very careful when looking at or using roast profiles done by others on different machines.

So I had my roasting landmarks and now needed to figure out navigation with the BC-600 - ie, how it responds to changes in gas and airflow. The first thing to note is that the BC-600 has an insulated drum. I took this photo when I had the cover off and you can see that there is about 3/4" of fiberglass insulation around the drum (notice also the direct drive motor - no chain).



The roaster also weighs about 120 lbs, which I think is about 4 times as much as the Huky, so it has a lot more thermal mass. It also has three burners, which for a roaster this size is plenty of BTUs. So between the greater thermal mass, the insulated drum, and three burners it has plenty of gas power. So far I've found it requires a much lower charge temp for a 340 gram batch compared to the Huky, about 300F versus 350F. With the insulated drum and three burners it also does not require much gas during roasting. It heats up pretty quickly with just 2 Kpa and I could roast 340 gram batches with a max gas of 1.5 Kpa and achieve a Nordic roast profile - something I couldn't really do with the Huky. With the Huky I often had to max out the gas at 2.5 Kpa for a 340 or larger batch size and the roast times stretched out to 12 plus minutes. I have a 5.5 Kpa Marshall regulator but I think this machine would probably be just fine with a standard 2.75 Kpa regulator (when I test some larger batches later I will confirm this).

The hot air also functions a little differently on this roaster than the Huky. The main difference is that it has a proper cyclone which means you don't have to empty the chaff after every roast as it will not adversely affect the airflow as the chaff is all captured in the cyclone outside of the airflow path. While the cyclone is not huge it only filled up about a third of the way after four 340 gram batches.



The removeable tray underneath the drum and burners was virtually chaff free after four batches - an improvement over the Huky. The lowest airflow setting is about 25% on the dial, at settings below that the motor stops turning. And from there the airflow increases very quickly and seems to virtually top out at about 50% on the dial. So that 25% between those two settings is the usable range. At a given gas level airflow seems to reduce the ET (probe is placed right in the bean chute and where the air exits the drum), but this also increases convective heating.

The temperature probes seem to be quite fast and responsive. Temperature readings from Artisan were very reliable and I could even reduce the sampling interval all the way down to one second and get good results, but I have set it at 3 seconds based on Artisan recommendations. I have not noticed any spikes at all in the course of roasting, but in order to avoid some of the choppiness in the curves due to the probes responsiveness I have added some moderate smoothing in the settings. The only issue I have encountered with Artisan is that if I shut off the gas after charging and then reignite after turnaround, Artisan will stop reading. I believe this is due to some kind of electrical noise or interference caused by the electrical ignition. At Marko's suggestion I tried using a USB connecting cable with ferrite cores, but that didn't work. Instead I've been just turning the gas as far down as I can at charge without turning it off. It would be nice to find a solution to this, but I can live with it.

This morning I was able to produce some decent looking Nordic style roasts with a total roast time of around 9:30 and hitting first crack around 8:00. Below are two of the profiles. I'm looking forward to trying these out but want to give them at least 5 days or so of rest.




Overall it seems like a very promising roaster so far. The beans look nice and even (with no tipping or scorching despite an aggressive roast) and the cooling tray cooled them down very quickly as the fan is very powerful. It was also really nice to have the cooling tray vented to the outside and get virtually no smoke/smell in my garage. With the all the functionality of a full commercial roaster (hopper, cyclone, exterior venting, electronic ignition, etc) its a real pleasure using this roaster. As I get more comfortable with the work flow it I can see that it will be very easy doing back to back production roasts.



I plan to do experimenting and depending upon the results in the cup may stretch out the total roast time a little and/or add some additional development time - particularly when I get around to roasting some naturals. I also plan to experiment a little with some different batch sizes and try to get a better handle on the capacity. But for now I will focus on the 340 gram size as that fills my grinder hopper and the bags I use.


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Balthazar_B
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#16: Post by Balthazar_B »

Given the sheer mass of the roaster and the insulated drum, how difficult is it to hear first crack vs. the Huky and other roasters you've tried?
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keno (original poster)
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#17: Post by keno (original poster) replying to Balthazar_B »

With an insulated drum you might think that but it's no problem at all to hear first crack. I think the sound radiates out through the face plate as it's actually quite pronounced. I don't normally roast as dark as second crack but I'll have to give that a try sometime to see what second crack sounds like.

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FotonDrv
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#18: Post by FotonDrv »

Ken, in the photo you Posted of the insulated drum I can see insulation on the outer shell that looks like a high tech fiberglass but what is that stuff that appears to be on the roasting drum itself?
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keno (original poster)
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#19: Post by keno (original poster) replying to FotonDrv »

There is an outer decorative sheet metal cover and then under that is the fiberglass insulation. In the photo I removed one section of the fiberglass insulation to better show the thickness. Under that is a plate steel cylindrical housing that surrounds the drum. So you do not see the drum in that photo. So the drum is effectively enclosed within three layers.

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FotonDrv
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#20: Post by FotonDrv replying to keno »

It looks like there is insulation on the mid level shell as well.

There must be openings on the inner shell to allow the flame to contact the drum; am I correct?
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