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

Buying a new “Air Fryer” (basically a toaster oven with a fan in it) led to re-discovery of what a great coffee roasting method this can be!

A current craze in the kitchen is the Air Fryer, which is most cases is a glorified convection toaster oven. This means it’s a typical roaster with a high speed fan to move hot air around food, and cook quickly and evenly.

There have been many types of convection ovens and toaster ovens for many years. But I guess it took the new “air fryer” moniker, and the fact that the one I use (Cosori Brand, 30L, 31.7 Quart, CS130AO Model, $199 online) has a rotisserie. I saw some inexpensive metal mesh drums online, and the fact the spit in this Cosori model fit, and said, “what the heck, I’ll try it.” I mean, I needed a new toaster oven after all. Note that when I talk about an “air fryer toaster oven here” I mean just that … the type that looks like a big toaster oven! I think many types of air fryers are obviously not right for coffee roasting, such as the HotPot types, top loading ones, or ones with front loading fryer baskets and such.

Cosori Brand, 30L, 31.7 Quart, CS130AO roasting a pound of coffee.

How to Roast 1/2 to 1 Pound of Coffee in an Air Fryer: Video

So here’s my video about roasting coffee in a convection oven air fryer. I roast a 300 gram batch in this video, using the best method I have at this point (and after burning through a lot of coffee!) I am still refining my method, but most of my batches are turning our really well. In this video I discuss what has and hasn’t worked for me, the best settings to use, and the cupping results of various batches I roasted while searching for the best settings and technique.

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

Oven Coffee Roasting Then and Now

We used to talk about oven roasting / toaster oven roasting. It was part of the original material I created when I started Sweet Maria’s in 1997! But roasting in an oven dropped off the radar for several reasons. The main issue was that it was hard to move the coffee around and roast evenly.

That is still the case with the convection toaster but much less of an issue since air flow is creating more even roasting. The other drawback was that oven roasting could be too slow, baking the coffee rather than roasting it. But the newer air fryer toasters can roast coffee in 15:00 or less, with first crack being possible at 10 to 11 minutes.

Roasting coffee in an air fryer or other convection toaster oven with an internal fan / blower works well! Especially considering that you might already have one in the kitchen!

Air Fryer Rotisserie Drum for coffee roasting
Air Fryer Rotisserie Drum – Seems like a good idea, but difficult and it roasts too slow!

Roasting Coffee in a Rotisserie Drum

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. I want to explain why you should not go this route … or more specifically, why it isn’t the best way to use your convection toaster/ air fryer to roast coffee as far as all my testing goes (and I did a lot of roasts and burned up a lot of coffee trying!) Sure, roasting in a drum is even and yes, it turns green coffee brown. And yes, it looks more “pro” than cooking coffee on a sheet or in a basket. Anyway …here’s a separate article explaining the problems with using a Rotisserie Drum in a Air Fryer Toaster Oven.

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!

Pros and Cons of Convection Toaster Oven Coffee Roasting or Air Fryer Coffee Roasting

I am still working to master my method roasting in my air fryer toaster oven. I have tested many variations though and gone through a lot of coffee doing it! It’s not that bad though; most of my test batches are quite good, and it’s a fun process to figure out which way is best. Note that I can only speak to the particular equipment I am using, and that this method, like all cooking and experiments, involves some risks to you and your equipment. I am not endorsing this, just trying to be helpful so you can learn from all my trials and errors:

Pros: Reasons the air fryer or convection oven coffee roasting method might be worth a try!
  • This seems great for roasting larger amounts of coffee, up to 1 pound. I prefer half pound, up to 300 grams in the model I use.
  • You can see and hear the roast process … like really well! (It depends on the ovens internal light of course. Many of these have as yellow hue too). Since the coffee lays still in front of you, you can see first crack happen as never before, and it’s kind of magical! It’s easy to hear first crack too.
  • This method seems best for medium roasts (City+ to Full City). The light roasts tasted a little flatter and less sweet than other roasters we sell. Dark roasts are fine, but the smoke produced as coffee enters 2nd crack can get overwhelming. Maybe you are willing to carry your machine from the kitchen to the patio or garage to roast each time. Not me.
  • The roasts can be really nice, especially the Full City roasts carried just to the edge of Second crack. They have a nice bittersweet quality and the Kenya I tested had a lot of the blackberry and black currant fruit I so love.
Cons: Reasons you might want to not roast coffee in a toaster oven or air fryer like this…
  • You need a convection type model, or an “air fryer” to do this well. A regular toaster oven without a convection fan isn’t the same thing.
  • I really can’t speak to other types of air fryers at this point either. I can only refer to my experience with the front-loading types like the Cosori brand one I use. Other’s have actual air fry baskets and those seem inappropriate. But I don’t know that for a fact.
  • Chaff can come off the coffee and get on your burner or into your fan. It might be bad for the machine. Like other things you cook in your oven or air fryer, it can ignite. We don’t sell toasters and air fryers for coffee roasting. So be cautious and alert. You never, ever step away from any roaster when it is in use. That goes triple for this method.
  • I am still battling “hot spots” in the oven chamber. Since this is largely a static method – the coffee doesn’t get rotated and turned, but largely lays still while hot air circulates around it, some parts of the cooking tray show lighter and darker roast areas. Playing with different trays (perforated trays can help), thicknesses of coffee, and patterns of distribution of the beans on the tray can all help. Agitating the coffee during the roast works, but it’s hard to fully rotate coffee on a flat surface. Simply shaking the tray doesn’t generally do this. But you likely can develop a technique that does pretty well.
  • Opening and closing the door of the oven toaster to see the coffee or shake it around loses heat and affects the roast.
  • Possible Deal Breaker! Think about it: A coffee roaster is not a great multi-function machine. You might not think a rotisserie chicken cooked with the scent of coffee roast smoke sounds bad. But you likely won’t go for coffee with the taste of rotisserie chicken infused in it. Right? So if you use the oven for other functions, they might not be conducive to roasting coffee and vice versa.
  • See the “roast range” note in Pros, since it includes the cons of lighter City roasts tasting less sweet than other methods, and dark roasts being too smokey for the kitchen.
  • You need to cool it manually outside of the oven, in a tray. You can use a colander, or use a cookie sheet as I do, which transfers heat away well by spreading the coffee in a thin layer and conducting heat away as well.
  • Potential dangers with handling the hot oven tray and coffee, transferring it to cool, etc. Not for the super clumsy. Luckily I am just regular level clumsy.
  • Chaff: It doesn’t come off the coffee during the roast. The presence of chaff on the coffee has little effect on the quality of roast but it throws off your perception of roast level, and makes the final result look a little funny. Chaff is easy to remove while cooling, with a fan and some stirring. Best done outdoors though because it is messy.

Does it seem weird I titled this “Toaster Oven Coffee Roasting Method – It Works” and then list all these Cons? Well, I just want to not over-promise. This method is definitely worth a try, especially if you already have a convection toaster oven / air fryer!

Convection Oven Roasting FAQ

Please add your comments or questions to this post, and we will incorporate them into the FAQ below:

What is the best Air Fryer to buy for roasting coffee?

I’ll be honest and say I don’t know. I chose the Cosori CS130AO because it was high wattage (1800) and had a rotisserie spit, but that turned out not be ineffective for coffee roasting. It’s also the size of a medium microwave, so I would likely opt for something smaller and without some features like the rotisserie. Let us know what works for you in our comment section below, and I will add it to a list of models that are ok for coffee roasting.

What is the ideal roast time to aim for in an air fryer?

From my tests, you want to push the oven to roast as fast as possible, while still maintaining an even yellowing/tanning phase early in the roast. I have had the best results with 15 minutes to roast 300 grams to City + roast level. I would like to reduce the roast to 13 or 14 minutes and see how that cups, but haven’t had success speeding up the roast while maintaining an even heating phase early in the roast. Preheating the oven is definitely good to get the roast moving, so I recommend it. I can definitely say that my roasts that lagged over 20 minutes had less sweetness.

By the way, what is an air fryer?

The type I have is basically a fancy toaster oven that has convection, that is an internal fan. I had a toaster oven with “convection bake” setting but the air fryer has more controls, and 2 levels of fan speed. There are other configurations of “air fryers” and some seem incompatible with coffee roasting. So in this article I am referring to the toaster oven type with a glass front-facing door.

4 Responses

  1. I have been roasting my coffee on a perforated pan in my regular oven which has a “quick bake” setting which is actually a convection oven setting. It works beautifully and makes delicious roasts. As the article said, it does roast a little unevenly but I think that adds something to the complexity of the flavor (maybe that’s just my imagination). I just cool the beans by shaking them in a strainer over the sink after a few sprinkles of water to start the cooling. The shaking separates the chaff nicely. I can roast a 1/2 pound on a tray but it gets more uneven if I try two trays at once in the oven. Thanks for the article.

    1. This is great to know. What model oven is it? People have told us for a while that newer ovens have a lot of convection as yours does, but our “oven roasting” instructions really focus on roasting in a non-convection gas or electric oven. I really did find that I could overcome the issue of “hot spots” by slowly heating the coffee in a thicker layer until slight yellowing occurs and then spreading it out. I also maped out the hot spot by doing a roast with a single thin layer, then I spread the coffee out in the next roast avoiding those areas… seemed to help. Anyway I agree that, as long as the coffee isn’t getting scorched in the hot spots, it can add some complexity. Thanks for the comment.

  2. I always enjoy your enthusiasm and fearless tendency to geek-out and explore the world, Thom. That’s the main thing I want to say here.

    Our Air Fryer is a Cuisinart model with a perforated tray. I think it would be just right. I have the ability to monitor power use at quite a granular level, and this thing uses more power than just about any 120 volt appliance we have. Way more than the Hottop (which is applying the heat far more efficiently, probably) and more than my Behmor by about 200W. I have no doubt it will have enough heat to turn some beans brown in a timely manner.

    I wonder about this popular notion that you need a constantly decreasing Rate of Rise of bean temperature? This probably depends on roast method to a large extent? Would you try to pay attention to the Rate of Rise in the Air Fryer? I guess you wouldn’t in a popcorn popper, and this is more like that than a drum roaster.

    In my Hottop, I do seem to need the declining Rate of Rise. In the Hottop if the RoR curve is not right the coffee tastes flat. I went through a lot of coffee in the Hottop with some bad roasts learning this. Now I pay serious attention to the RoR, and roasts are great.

    I started in a Behmor, which I still have, and who knows what the RoR might be. I doubt I’m getting a “perfect” or even good RoR curve in the Behmor, the way I was roasting at full power, but most often great results — better for smooth chocolate than bright fruit. I’ve had fewer great roasts in the Behmor, at least according to certain flavor profiles, but almost all 450+ roasts in it have been at least pretty good to great. Smooth and chocolate flavors are fantastic in the Behmor, even if it’s harder to get clear, bright fruit flavors.

    Next time it’s OK to smoke up the house I’m going to try the air roaster.

    1. Well that’s a great question about the rate of rise, and I really don’t know. But I suspect like you it is very different for different roasters. But it also seems like the bean mass itself matters, and with small roast batches like a home roaster the coffee doesn’t “roast itself” as much as a large commercial roaster … so that has a bit impact on rate of rise. Anyway, my best guess is that the ROR for each roaster is going to be really different, and also hinges on what style of roast people want … I think this question could be a whole Phd thesis likely! Big question

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.