Moved from Behmor to Hottop- How to Keep Body

Discuss roast levels and profiles for espresso, equipment for roasting coffee.

#1: Post by jlehet »

I've been roasting for over a year and a half on the Behmor. We drink a fair bit of coffee, and I've gotten pretty good at getting a variety of origins to come out in ways that please me on the Behmor. 360+ roasts, most of them very drinkable or quite good -- better than I can buy locally anyway. I know there are notes I couldn't hit -- clean bright and clear fruit, for one thing. Basically I'm a beginner still, but I've gotten to know what the Behmor can and can't do by now.

I often roast with a Variac. We have solar panels, and on a sunny day my line voltage is quite good, over 120v at the outlet before drawing through the 12 gauge wire. And the variac of course gives me 120.

So now I've been roasting with the Hottop 2k+ for about a week, hooked up to Artisan. I've adopted a very different approach than I used on the Behmor, based on youtube videos I've watched of Hottop roasters and Artisan roasts. There are many more possibilities. With the Behmor most of the time my approach was to give it as much heat as possible, spin the drum faster, and hit cool at at the right time -- the latter being the main trick. Of course taking it out of the cool cycle after a minute instead of 12.

On the Hottop my main approach with variation has been to use between 150 and 200g of beans (I'll standardize eventually). I've been charging at between 380 and 415, heat to zero until turning point, then heat at 100, backing off a little before Dry End, more air, less heat as I go along, hitting the heat a bit after maybe 10 sec of First Crack. Unless I want a darker roast I'm dumping right the beans right after the end of First Crack or maybe 5 or 10 seconds longer in general on this roaster. I'm trying to keep my RoR curve generally declining. I suspect maybe too much emphasis on that is the problem I'm having.

I haven't yet tried all my roasts (resting), but I'm feeling pretty mixed about my results. I know the Behmor is known for emphasizing body and complexity over brightness and clarity, so that is what I'm used to. One Hottop roast of Flores was exceptional. There was a nice brightness along with a clear and delicious strong sweet chocolate. It was like a tangy chocolate bar. I had never roasted anything that good on the Behmor. Still, it didn't have as much body as I might expect.

On the other hand both a Colombian and a Honduras roast resulted in thin, flat, bright but uninteresting brews. I've been reading about "Flick and Crash" a bit, and my Artisan curves don't show that as a serious issue in these roasts. But these roasts seriously lack flavor that should be in the beans. I thought I got all the way through FC and the beans are dark enough to look like what I would call City+ from my past experience. The Honduras I know is an excellent coffee, very fruit forward with a chocolate background. But the cup I just had is thin and insipid.

I can post Artisan graphs of these if anyone wants to look. But I guess the main question I have is what principle in the roast promotes body in the cup, and how can I get a bit more of that? I'm wondering if attempting to keep the R0R curve going down is sacrificing flavor development?

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#2: Post by mkane »

I feel your struggles. I don't know the Hottop but set air and forget it. Also try not to raise gas. Just carry enough momentum into 1C to keep from stalling.


#3: Post by jlehet »

I don't think it stalled. So the Honduras roast hit FC at 358 BT. BT rose through FC, FC ended at 386. I dropped the beans at 388.

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#4: Post by mkane »

Increasing air to close to 1C will either cause R0R to flick or crash


#5: Post by jlehet »

I have been increasing air just before FC. Sometimes I see a peak and dip in the RoR curve through FC, sometimes not as much -- depends on the beans it seems. I will stop doing that with the air! Any advice for a 2k+ hottop roast coming into FC as far as an air setting?

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#6: Post by mkane »

Peak and dip heading to 1C means to much mid roast gas. Use just enough air to get rid of smoke & chaff. Take a look at my post next to yours about struggles with taste. Mine seems to be water related I hope. Take a look at gas settings, always declining. I set air and forget it.


#7: Post by jlehet »

20 some roasts later on the Hottop with Artisan, I've gotten better, though I don't pull it off every time. I haven't tasted all of those 20, but I am making a lot of small pots and single cups to try today.

It's funny, the Behmor is frustrating because it has so little power available to change anything during the roast and there is so much intertia. But then the flip side of that is that the environment and roast process is very stable. Over the last year and a half I had evolved tricks and compensations (my roasts probably even had a nice RoR curve, but who knows). Likely the Behmor doesn't flick and crash. I missed brightness, clarity and some of those upper notes, but I also appreciated the smoothness and body and lower-end complexity that the Behmor gives. It was pretty rare to get a bad roast on it by the time I got the Hottop.

The Hottop is a whole different world in terms of results. It's still rather hit or miss. I still sometimes get flicks and crashes, or roasts that don't taste really great even when the curves look pretty good to me, as far as I can tell. I'm coming along with it.

I was charging too hot. I'm getting a fair number of roasts close to 40/40/20. Figuring out when to drop is a new skill compared to the old skill (probably even harder to learn when to stop a roast on a Behmor, but you get used to it after about a year).

I think I won't sell the Behmor yet.

I'm drinking too much coffee today. Zzzzzzzztpxt!


#8: Post by rmongiovi »

mkane wrote:I feel your struggles. I don't know the Hottop but set air and forget it. Also try not to raise gas. Just carry enough momentum into 1C to keep from stalling.
Keep in mind that the hottop is electric and changes to power take a considerable time to have an effect. It's essential to plan ahead.


#9: Post by jlehet »

Having been a (successful) behmor roaster for 18 months, I'm vividly aware of the lag in electric roaster response. Based on both the graphs, the results, and what I know about the hottop by now, it is a lot more responsive than the Behmor, and of course I can decide on the instant and knowing the bean temp when to drop. Changing air can change the dynamic of the roast (for better or worse), adding some control. The hottop may be a lot more responsive to changes in heat than the Behmor because the heating element is a lot closer to the drum, while the behmor's elements are heating the relatively larger chamber. However the opposite may also be true with the behmor: the beans in a relatively insubstantial drum are directly exposed to the element.

It may also be that I need to rest the roasts more than I am. In my Behmor roasting flow I had a stash of roasted beans, and the rest period before drinking often was 4 days to a week or more. Now I'm trying to evaluate after two days rest, which is different from what I'm used to. I just realized that while sipping the current cup, an fruity Ethiopian Suke Quta Daanisa. I hadn't even bothered to try it close to roasting, because according to the hottop experience I was developing around that time I figured I had probably ruined it. After 6 days it's not fantastic but it is drinkable. I thought for sure it would go into my blend-into-cold-brew stash.

Anyway, yeah, electric and lag - hottop specific advice might be appropriate - charge temps, air control, etc. I am anticipating the future with thermal adjustments, but I'm still not getting fantastic roasts most of the time.


#10: Post by rmongiovi »

I was specifically responding to mkane who has been giving gas based advice. Being electric the hottop already has plenty of momentum.

I also roast with a hottop 2k+. I try to follow the "continually declining ROR" advice but I found that the thermocouples in the 2k+ made that very difficult towards the end of the roast (at least, with Artisan at the time). The problem is that the 2k+ returns temperatures as integers; there are no digits after the decimal point. So the more slowly the temperature is rising the more Artisan sees a RoR of 0 degrees followed by an instantaneous rise of 1 degree. Early in the roast where that's happening relatively quickly smoothing fixes it. But at the end of the roast you end up with sinusoids in the RoR graph due to the inadequate resolution. That makes it really difficult to determine if your RoR is steadily declining.

I ended up modifying the roaster to use my own thermocouples using a phidget which I believe has something like 5 digits after the decimal. That alleviated the sinusoids. I can now happily report that my crappy roasts are entirely due to my lack of skill.