Roasting Coffee in a Rotisserie Drum in a Toaster Oven Air Fryer

Some Air Fryer / Convection Toaster Oven models come with a Rotisserie spit, and it’s possible to roast coffee in them. Here’s why you shouldn’t do it!

I bought this particular model of air fryer because it had a rotisserie, and because the spit rod that came with it fit and inexpensive metal mesh wire drum sold online. The air fryer toaster oven I have been using is this: Cosori Brand, 30L, 31.7 Quart, CS130AO Model, $199 online. The drum is sold under various names, mine was called Falytemow (!?!) Stainless Steel 12 x 18 cm Rotisserie Drum, $19.99. The plus side of this pairing is the drum does fit on the Cosori roasting spit rod including with the oven!

So let me back up … I am definitely not saying you shouldn’t do this! Roasting coffee in a rotisserie drum does indeed turn green coffee brown! It’s just not as easy as it seems…

I just want to share my experience, which was a surprise to me, a person with 30+ years of coffee roasting experience. I was really shocked how difficult this was to judge the roast, how slow the roast process was, and how the coffee turned out. At the same time I was more surprised (pleasantly) that roasting on a flat sheet using high convective air flow on the “bake” setting, or on the air fry setting, has great potential!

The drum roast was very even I admit. The coffee looked nice.Why is it so slow? Partly this has to do with the limited heat range I mention below. But you can roast at 400f max temperature in other modes. Why? Because the coffee is not massed together in the limited drum space; it is spread out thin on a sheet.

A solid drum commercial roaster versus a rotisserie: Two different things!

400f is not hot enough as an environmental temperature for drum roasting. Commercial drum roasters are capable of much higher ET. And most important, in a commercial drum roaster you aren’t heating a huge space around a perforated mesh drum; you are transferring heated air directly through a solid steel or cast iron drum.

The heat transfer is completely different. Even though both are “drum roasting.” they couldn’t be more different. (This goes for roasting on an outdoor barbeque rotisserie as well but that’s a different egg to crack). That’s not saying a mesh drum or perforated drum rotisserie can’t be used to good effect. It does after all turn the coffee around … but even that is not at all like the design of the commercial drum roaster. Perhaps some illsutrations help:

Coffee roaster illustration from the web labeled as Probat Air Flow. I don't think that is right - it appears to be a recirculating Jabez Burns Thermalo roaster type
An image from the web, which was labeled as Probat Air Flow. I don’t think that is right – it appears to be a recirculating Jabez Burns Thermalo roaster type to me. Needless to say, it documents air flow channeled through a solid drum, which has a complex system of paddles, not much like a perforated drum / rotisserie operating in a large hot box at all.
Sketchy sketch: To illustrate this I attempted  to draw how a drum coffee roaster of the commercial Probat variety focuses air flow through a solid drum. But a rotisserie type roaster with an "open mesh drum" has no "focused" air flow.  It's a turning cylinder in an environment with general air blowing around in it. One is like a wind tunnel (the solid drum roaster). The other is like a windy place.
Sketchy sketch: To illustrate this I attempted to draw how a drum coffee roaster of the commercial Probat variety focuses air flow through a solid drum. But a rotisserie type roaster with an “open mesh drum” has no “focused” air flow. It’s a turning cylinder in an environment with general air blowing around in it. One is like a wind tunnel (the solid drum roaster). The other is like a windy place. -Thompson

Some of my issues might be with the model I bought, the Cosori, but I did seek out the highest wattage model with a rotisserie spit I could find, so perhaps these are issues with many models with and with drums like this.

The biggest issue: You really can’t see the coffee roast level at all. I end up feeling like I’m lost as to where the coffee is at in the roast process … and I’ve been doing this quite a while on many types of roasters! To stop the drum, check the coffee by opening the door (burn alert), reinstalling it, and starting up the process again is difficult and impractical.

The roast results were indeed even, but the installation and removal of the drum spit made it too hard. Pinpointing the stopping point in the roast, which matters by a measurement of seconds in coffee roasting, was guesswork to some degree. Opening the hot drum to get the coffee out to cool was painful, since I don’t have those neat high temperature gloves.

It’s not impossible of course. Here’s my tips: Set the fan speed to the highest possible. Since my oven restricts rotisserie high temp to 400f, it’s important to preheat the oven, then put the loaded drum in to start roasting. Listen carefully as coffee sounds can be confused with first crack, especially since first crack is faint sounding in a long roast process. Push the heat as much as possible to get the roast done asap. My fastest, despite all my efforts was 25 minutes, which is slow and results in a somewhat flatter roast taste in the cup. You can get some improved visibility of the coffee in the drum by shining a strong led light through the front glass of the oven, upward toward the drum.

While I found the rotisserie setting disappointing, I became curious of the potential of the air fry settings and similar ones available by using “bake” function but manually setting the fan on the highest level possible. And I had some good results! (Please read the main article about Air Fryer Coffee Roasting / Convection Oven Coffee Roasting for details).

Related: Toaster Oven Coffee Roasting Method (Air Fryer – Convection Toaster Oven)

16 Responses

  1. I have been roasting with the Ronco Showtime oven for five years now, and the roasts turn out great, at least in my opinion, and i have been roasting with every roaster under the sun since you guys have been in Ohio. Can’t remember his name, but a guy on the internet builds drums to accommodate the Showtime. I picked up four Showtimes at yard sales for next to nothing. People buy these things, then never use them. Basically, I am set for life if they all have a decent life span. The drum is stainless and built well. I roast mostly by sound, and when I get first crack or whatever, I shut the cook cycle off, but leave the drum on, open the glass front door, and point a small fan in at the drum and let it cool and loose chaff for about 15 minutes.

    1. Great to hear about this … 5 years is a long time so I can see this definitely works well for you. Can I ask you a couple questions? How long is the roast cycle with the drum. This is the issue I was having with the set-up I am trying to use. Is the drum a wire mesh? Perforated sheet? or Solid? Very curious…

  2. I have been home roasting for about a decade, on and off using a cheap convection oven. I recently upgraded to a 1500W HomeLabs Rotisserie Convection Oven, and a Falytemow Roaster drum. Stock, it restricted rotisserie temps to 350F, and the rotation was maybe 2rpm. I’ve since modified it to operate up to the max temp of 450F with rotisserie on, and replaced the motor that’s now 24rpm. The system now rotates up to a full pound of coffee, at full temp with convection fan on. I’ve done a few batches at a variety of weights, 1/4 lb to a full pound at various temperatures. With a 1/2 lb load, what do you recommend to set the temp at, at various times throughout the roast? In your video, you preheated to 450F, roasted at 400F and sometimes increased it to 415F about halfway through the roast. I’ve read conflicting advice that says that drum roasting is best at higher than 450F, so I’m confused. I’ve roasted 1/2 lb of Ethiopian coffee in this setup without preheat at 450F constant temp and got to City + in 13 minutes. The results weren’t as good as hoped, and I thought maybe I should start out at 400F preheated (as you did in your video), and change the temp somewhere along the way to approach a recommended profile. What do you recommend? I prefer light-medium roasts up to Full City .

    1. Hi Steve – I’m really interested how you modified the motor to such high RPM. That’s great … more drum rotation has the effect in coffee roasting similar to increasing the air flow, so higher drum RPM is almost always a plus for quality. As far as idea temperatures, I think it is hard to pin that down. Drum roasters with a mesh type drum are completely different from cast metal or steel commercial roasting drums. They need to be approached differently … that said, an environmental temperature higher than 450 would be really hot and likely roast on the fast side. The best roasts I have had when pushing the heat higher is around 8 minutes to first crack (just the start of it), and finishing roasting about 10:30-11:00 for a medium City+ roast. Longer roasts have been good, but the coffee tastes flatter to me … which is nice for espresso use but not as good for brewed / drip coffee IMO.

  3. Hi Thompson-

    I tried many modifications before I got it all to work to my liking. I believe most toaster ovens with rotisserie use the same size/type of motor. They are all 2-3 RPM, which is too slow. I purchased 3 higher rpm motors until I got one that worked properly. The first 2 were the same physical size, but the higher rpm was a problem. The design of those smaller motors don’t have enough torque to spin the weight of the roaster cage and coffee at ~30rpm, and the motors stall and reverse continuously. Luckily I found one with 3x the torque, with 20-24rpm speed. That did the trick, and the setup can support a full pound and rotate without struggling. The higher torque motor had the same mounting bracket and circumference, but it was about twice the length. Luckily, it fit fine with the chassis cover on.

    The motor that worked properly was the “CHANCS 50KTYZ AC 110V 20-24RPM Synchronous Motor Geared 6W CE Pass Gear Motor”. https://www.amazon.com/gp/product/B013W3TZES for about $20. There’s also a version that’s 50/60rpm, but I was afraid that might be too fast for this application. Also, 10rpm. Not really sure.

    This motor did require additional wiring, as it has 4 wires (stock is 2), with a capacitor. I wired it to a small toggle switch on the front of my oven, and I can run the drum clockwise or counterclockwise depending on switch position. It wasn’t that hard. If you want more details, I took a bunch of pictures which I can provide.

    My suggestion is to pop the cover of your rotisserie oven, and see if it has the same main dimensions and shaft length and location as the 50TYZ motor. If it does, you should be able to replace it as I did. But verify it’s the same voltage, mine was 110V.

    The only negative about the setup is that with the rotisserie cage spinning the beans, it’s hard to hear 1st crack. But the toggle switch I added allows me to stop it and listen.

    steve w.

  4. I to have been roasting with the Showtime for about 10 years. I modified it years ago to accept a heat gun running on high. My roasts consistently run at 450-500F and last from 12-16 minutes depending on outside air temps. I used a hole saw and drill to cut a hole in the non powered side of the showtime.

    1. Interesting! I didn’t know this was an option honestly. It’s a bit like the Gene Caffe roaster, mechanical drum moving the coffee, hot air stream for roasting. I bet the roasts are very even. Brilliant!

  5. Most confusing review ever. I doubt “not through it” is actually a thing. The drum does move every bean due to rotation, doesnt it? That means all beans take turn to be briefly close to the heat source.

    Coffee roasting is all about speed and if the roast did not turn out good I assume the temperature was not right then.

  6. Hello, last year I got this Airfryer with a rotisserie basket and ended up here while searching for how to roast coffee at home. Thanks for triyng this anyway! I am thinking about trying it myself with some generic green coffee I got and was wondering how much coffee you would say is the minimum amount to do this? I wasn’t planning on roasting a lot since I’ll probably burn it hehehe

    My Airfryer is this one here (also 400oF max temp) https://www.oster.com.br/fritadeira-super-fryer-10l-oster/p?idsku=4690&gclid=CjwKCAjwy42FBhB2EiwAJY0yQkmg0yo5LoiSM1uiUlpEvH0A_rM9KkNG3sXtNd5jX1UmJ_9_OrPCHRoCaBoQAvD_BwE

    1. I looked at the model of Oster and I think that would work. My advice is to preheat it to the highest temperature and then use the highest temperature setting to roast, with the air fan on the highest setting. As for the amount of coffee, I think its best to fill the tray you roast on so its not more that 1 – 2 beans thick. Don’t overfill it. In mine it tends to roast faster on the outside areas of the bean tray. If there is a safe way to open up the oven and move the coffee around in the middle, I would do that, to roast more evenly. It’s going to take some experimenting, but my results were quite good.

  7. I roast all the time using a German air fryer with a mesh drum. The fryer claims to get a maximum of 450 degrees. I roast 1 pound at a time, maximum. Preheat the oven to 150 for 15 minutes. Then i pack the drum with metal objects: and old steel food chopper, a steel can opener, a steel garlic press, the prongs you put into each side of a chick when roast it on a BBQ rotisserie. The metal increases the heat in the basked and forces the beans to circulate. Between the airflow sound and the noise of the fryer motor I cannot hear the roast very well. I also cannot see the roast unless I quickly open the roaster, but i have done it long enough to not worry about it. I know that 21 minutes for one pound on most beans gets my beans to a nice lighter city roast. When I am finished there is a little smoke coming off the beans; just slightly. You do have to be careful; the basket gets very hot and I have lots of scars from burns. Oh yes, I roast for 10 minutes at 450 and then drop the temperature to 410 for a minute, then raise it to 430 for another minutes, before raising it to 450 again for the remainder of the roast. When I am home just hanging out Ido 3 consecutive roasts. I am not sure what absolutely delicious coffee is. All I can say is that I like my morning coffee. I should also point out that I roast for everyday use so I am using the most economical specialty beans I can find.

    1. Wow – this is very unique. But it makes sense to use these metal objects to help move the coffee within the drum, if not to conduct heat to the beans.

  8. Interesting article read and I agree on their own they really cannot roast the bean correctly. You really are going to bake the beans (slow roast) or have the drum rotate too slowly so possibly burn the beans. Also the chance of burning when removing the beans.

    As some people here have mentioned; I also modified a rotisserie roaster. Though I added a thermalcouple and control all the elements through an arduino.

    You are on point about the chaff; it can be a bit of a struggle to keep it clean.

    1. Thanks for your thoughts on this – yes the roast really is on the slow side. I think by pre-heating the oven you can get roast times into more acceptable ranges, but yes, there’s a risk with handling the drum and a hot oven / metals. Not fun…

  9. Wish I had known about that motor for the rotisserie! I couldn’t find anything with the same footprint for my modification. I eventually went with a 24V DC motor that I control with a microcontroller, but I had to make a bracket to get my moor to connect cleanly to the oven!

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