Yes, I notice that in the RoR graph for sure on my Hottop. So sinusoidal it's hard to see what's going on in the critical phase of the roast. That seems like a pretty bad deficiency on Hottop's part. If they're going to to go to the trouble of getting thermocouples in there and a USB interface, might as well have it be useful.

It is not helping with my frustration in learning to roast on the Hottop. I had very few roasts on the Behmor that I wanted to throw away, but I've already got several jars of bad coffee from the Hottop. I feel like I"m going to get it, and then I read this and feel less hope.

I did drink a decent roast of Guatamala Marco Roja today. It's funny, I did two roasts back to back a few days ago of these beans. The first one had an apparent flick and crash so I tried again and didn't have the flick part of it. Except for that the curves looked pretty similar. The one that seemed to have a big flick is the one that tasted much better!

I am getting better with the Hottop, though it is still more of a challenge than with the behmor, and I still find I have less body. I definitely get more flavors from the Hottop roasts, but it also kind of cuts both ways. This morning I brewed a Sumatra (Aceh Bebesen, currently in stock at Sweet Marias). It might be the particular coffee, which I haven't tried on the Behmor, but this is full of clean flavors and without the deep murky body I always got with Sumatrans before. On the Behmor a Sumatran was pretty much a Sumatran: full bodied, deep, murky. This Hottop roast, even though this coffee is Wet Hulled (Giling Basah), it is completely different. I dropped at 397F BT on my Hottop, which seems to show cooler temps from the probes than normal, I think. The drop was 3 minutes after the start of 1C

Also brewed this morning a Hottop roast of a Burundi (older beans, Kayanza Gakenke). This is a coffee I've roasted now and then for over a year on the Behmor. I'd say this roast was successful. Though I think the greens are getting too old (arrived at Sweet Maria's on 12/18), it's a little flat-ish (which has been a problem with my hottop roasts) but the fruit flavors are much clearer than I've ever tasted, but without the deep complicated body I'm used to. This one I dropped at 374F BT on the Hottop at 9:15, 2 minutes after the beginning of 1C and about 20 sec after the end of 1C.

The problem with my early roasts, which were super-flat and weird, was that I wasn't giving enough heat through the roast. Partly I was newly obsessed with getting RoR to decline (since I can see it for the first time) and partly I watched a youtube video of Hottop roasting (Black City Coffee), where she really used a lot more air and a lot less heat than I think I need to with her Hottop. I use a Variac, and I also know that when my solar panels are going my house voltage is nice and high. So I have as much power as the Hottop can make, if I use it. With Behmor roasting, you mostly just give most dense beans as much heat as you can get the thing to make from a wall socket, if you want any brightness at all. With the Hottop I've been running it hotter than I did at first, to good effect so far.
But still finding coffee is a bit harsher and without as much body and depth, less flavor on the "bottom end."

I actually read that paper before I made my last post. I also thought about the possibility you suggest, that there are other characteristics now that overshadow the body. When I read that paper, after my recent experience, I thought it was very clear they were wrong about body. But, science. I guess I don't know. I am prone to trust science. However I remember a consumer report article a couple of decades ago where their panel of expert tasters had decreed that Miller beer was the best overall. So there's that.

One thing for sure, is that learning to taste is an ongoing process, and we don't always like tastes we don't understand. One coffee I roasted some in the last year, and I still have over a pound to try some more, is a Colombian Honey Process Aponte from Sweet Marias. And I didn't like it much, even though the description sounded good, and in my Behmor days I was reliably generally getting roasts that pleased us here. Then one day not all that long ago I had that coffee in a car cup running errands. I guess a bit distracted by driving, so the experience was able to sneak in instead of hitting me full on and meet resistance. I "got it." If I remember, it was an unusual combination of fruity and caramel, which was very pleasing once I understood it. It's just that I hadn't tasted that combination before the way it showed up in that coffee.

So yeah, with this morning's Sumatra, the strong cedar taste, that takes the spotlight, while before all I had was the body. Interesting exploration.

Everything is improving, getting at least some coffees down I think. Right now drinking the Durato Bombe from Happy mug. The kind of clean blueberry I could only dream of with the Behmor. I've had a few single origin pour overs at coffee shops while traveling in the last couple of years, "Blueberry..." on the chalk board, and I'd come home and roast good Ethiopian naturals and never get those notes. Now I'll have to try to perfect some of the full body chocolate coffee we like as well.

I've been experimenting so much, roasting so much, since I got the Hottop I have to just stop roasting for a week or more. Way too much roasted coffee built up. I've got some early Hottop roasts I'm going to have to just throw away, which I've never done.