Level: Apprentice
Reading Time: 20 minutes
Drum roasters are so expensive. They are only a drum, motor and some heat. Isn’t there a cheaper alternative? Couldn’t I roast in a pan like they do where they make the cocoa beans. Would you tell me how to do that? Should I use low or medium heat?
As a reminder, the focus of this series is the Iron Triangle of Anguish/Needs/Desires where although you want all 3 things for something you only get to have 2 of them and it is a trade off.
A drum, motor and some heat…..that is an interesting way to describe a drum roaster. I would put out there for consideration that a roaster is more than that in the same way that a car is nothing more than a motor, a seat, 4 wheels and way to stop and go. Right? Why are we all not still driving a Ford Model T?
It is very worth noting that I have been as guilty as you are with this view and it took me many years to work out that the Iron Triangle will not be broken. Let’s talk a bit about my path.
Read All The Articles In This Series:
The Iron Triangle Of Anguish (ATA #310)
All about Cocoa Beans (ATA # 311)
Only a Drum, Motor and Some Heat (ATA 312)
Cracking and Winnowing in baby steps (ATA 313)
Melangers et al (ATA 314)
Tempering (ATA 315)
Over 20 years ago I was introduced to roasting my own coffee and for about $10 and a little bit of research I was able to buy a West Bend Poppery I, the gold standard for the DIY home roaster. It was originally used for popping popcorn but it also does a pretty good job of roasting coffee....mostly. I found I had to take it apart and disable the thermostat or it would not quite get hot enough.....then I had to install a thermometer to know how fast the roast was going....then I had to re-wire it because it was now too hot. Notice there lots of payment in labor because it was only $10. But this is about cocoa. What I quickly discovered was that cocoa beans don’t work well in a popper. The beans are too big and if you roast nibs the ends tend to get burned. That meant I had to move onto the next level since a roaster is just a motor and a container and some heat...yeah, right.
My next ‘roaster’ was a light piece of rolled up sheet metal and a couple duct caps and a tabletop hibachi. Drum, check. Motor, check. Heat source, check. Roasted beans....nightmare with the set up, lack of energy, slow drum and no way to tell what temperature my beans were. But I could fix this.
I took away the hibachi and installed it into a cheap propane grill. I now had a good heat source, and after a few roasts the light weight sheet metal started warping and that ended that.
Enter next the RK drum but it was really more suited to coffee and the large vanes just didn’t work well with cocoa and when I had them modified (thank you my friend, Ron Kyle, I miss you) I still was roasting in a black box and could not tell where in the roast I was. I’ve since explored a modified system to get a temperature reading but the labor equity was just getting too high.
If you notice, each great idea just lead to another aspect of the Iron Triangle. The cheap ideas didn’t work. The expensive ones left out some critical piece I needed, either temperature readings or power control. Over time I learned that building a roaster yourself was more complicated and expensive that just a motor, drum and some heat. To that end I started looking at off the shelf solutions where I let someone else do the work.
I explored the Gourmia Air fryer. It did ok but you got what you paid for (it was about $130). Again there was no direct temperature measurements, lowish capacity (about 1.5 lb) and worst of all, because of the very slow drum, inconsistent temperatures within the drum.
Riffing off that I can’t tell you how many kitchen rotisserie ovens didn’t work. Really, it was just more of the same. No control, no temperatures and/or not enough heat.
At this point I mostly gave up on being able to offer an affordable drum roaster to you, my chocolate making followers and just dove into making my own good drum roaster from scratch. For those curious, and I’m not going to name names as I don’t want you to use them, there are two heavily modified ovens out there for about $6000 the last I checked and they have all the flaws I have identified (no control, no temperature readings, and in these cases, under powered). You’ve been warned.
After failing at making my own drum I ran across a George Foreman rotisserie basket and with a little careful drilling (oh, yeah, I needed a drill press for that, thanks Iron Triangle) I was able to drill a hole in the shaft so I could insert a thermocouple probe. Bean temperature problem FIXED. Cost...$700 drill press. I then designed and built a roaster chamber frame around it. Ignoring all the inexpensive failed attempts (and more $$$) I had it built. Good structure with easy access, fixed. Cost $250. After adding in heat (I found nichrome heating elements, and halogen lights) I needed a way to control the heat so I added an off the shelf variable voltage transformer. Cost $250. A $60 motor later and another weekend building and my own 5 lb drum roaster was complete.....for a mere $1300. (that is it in the photo above).
Why don’t I build them and sell them? The short answer I think is pretty obvious. It is not cheap. The less obvious answer is one I’ll address at the end in more detail but in short it is safety certifications and our litigious society.
But why isn’t it cheap if I’ve worked out all the bugs or phrased another way, why are drum roasters so expensive? I have clearly rambled a bit, so let’s get back to your question.
Isn’t there a cheaper alternative? Couldn’t I roast in a pan like they do where they make the cocoa beans. Would you tell me how to do that? Should I use low or medium heat?
It sounds like you want to be able to buy a safe, commercial roaster that is inexpensive and will allow you to use it easily and with confidence, without undo effort on your part and will not burn your building down. I of course read between the lines there and made some assumptions as a way to outline some of the options that you might want and the trade off available to you.
Starting at the top, by asking why they are so expensive you are totally implying you want to buy one off the shelf, i.e. you don’t want to expend sweat equity to make it yourself like I have. You are right....kind of...it is only a drum, motor and some heat. I showed you a glimpse into my decade long journey of drum/motor/heat vs the Iron Triangle. Let’s take a moment and break those down and see if that assumption is correct or not.
A drum. Yep, it is a drum. Having hand made a drum I have not to tell you they are not trivial. The tolerances needed for a traditional drum roaster are pretty tight and with tight tolerances comes the need for good technique and ability and guess what? That is not cheap. You need it be a nearly a perfect cylinder. It must be open on one end so you can load and empty the drum and because of that, it must have a front plate very close....but not too close or as it heats up, the metal will expand and then you will be treated to the most hideous sound of metal on metal screeching you have ever heard. 0/10 would not recommend that sound. For a small roaster, of like 10-15 lb capacity, the scale allows it to work....but when you get to some larger roasters the coefficient of expansion of metal simply gets larger than the tolerances need for beans not to drop through or bind in a screech of death. In that case you need a front plate that is adjustable and oh look, it is no longer a drum, motor and heat. There is an adjustment system....which adds expense.
Now of course, you could decide to ‘fix’ that issue by having a drum that you have to hand load and hand empty, basically like the Behmor 2000. In that case you have traded some convenience to save some money. Cool. Problem solved.....but have you thought about how you are now going to measure the temperature of the beans? When the drum didn’t have an end, you could put a thermocouple through the face plate. Now the only two solutions I see are this:
Drill out the shaft (like I show in our Modifying your Behmor roaster and how I modified the George Foreman basket) so you can insert a thermocouple probe, or
Don’t have the ability to have a temperature measurement (again, 0/10, would not recommend).
For me, 90% of the reason to have a drum roaster is to have the temperature measurement.
It leads to consistency and reproducibility. I would just as likely drive my car blindfolded than roast without the ability to take temperature measurements. That really then means that you really only have one option and with that option you have increased the complexity of the drum to build, so that is now going to cost more money....except you decided to forego some convenience to save money....and that failed. Remember, TANSTAAFL !!!
Alright, I don’t mean to make this into a treatise on designing a drum roaster so I’m going to go ahead and mostly stop on the drum......and I lied. I want to you consider safety. I don’t know about you but I’m not a weak or easily intimidated person. It does not bring me joy thought to consider opening up a hot roaster at over 350 F that contains 20 lb of hot cocoa beans when I then need to lift out the drum (which empty probably weights 20 lb) and dump it all into some cooler. Right, you also have to do all that while trying to not burn yourself or drop the beans or any other likely issues. And would you ask an employee to do that?
I hear you saying you would actually ask an employee to use it. You are willing to make that trade. Ok. I suspect OSHA might have some issues with that. And if someone gets hurt, it is possible (read likely) that your insurance might have some issues with it also. Oh, and even if you are willing, there are these pesky safety standards out there that although sometimes annoying (I’ll get into that later) really are there to protect your ass from being a Darwin Award Winner . In short, no one is going to build one for you because we ‘mericans tend to be litigious as fuck and who wants to be sued for you accepting dangerous risks and then changing your mind.
Next up is the motor. Yep, it is just a motor. What may not be straight forward is how you are going to attach that motor to the shaft of the drum. It is surprisingly difficult to do with everything perfectly aligned and durable for 10s to 100s of thousands of rotations. There are couplings out there that will make it pretty easy, and I bet it will come as no surprise that they are also not cheap.
As I write this out I feel it might be worth mentioning that all of the things I’m writing about come from direct experience, just a few that I told you about above. At this point I have now designed and built over a dozen different coffee and cocoa roasters in the past 20+ years. I’ve been hit over the head time and again that the Iron Triangle will NOT be beaten. If you are at all curious, I’m the lead designer and builder for Behmor’s Jake 1 kg roaster. Time and again I had to make the 2 out of 3 decision. I am mainly pointing this out so that it is clear I’m not talking theory. I’m talking bench top design and fabrication I’ve personally had my hands on.
The final part of this this simple roaster build (yep, there is a little sarcasm there) is ‘some heat’. It is a roaster and of course roasters need heat. In there you pretty much have two choices.
Electricity
Propane (or natural gas)
Each absolutely have their pros and cons but once you get beyond about a 5 lb roaster (this is why my roaster has a 5 lb capacity), electricity is simply not a viable option, and under that, controlling that heat is not an insignificant design issue. You can’t just run out to Home Depot and pick up a controller to 1500-2000 watts of power. Light dimmers don’t go that high. Contrary to what many people think, a simple thermostat also won’t due the job. I know this might sound a little like a ‘how to build a cocoa roaster’ but it isn’t so I’m not going to dive into the ins and outs of controlling that much power safely and consistently. What I will say is it isn’t cheap and it isn’t trivial. Or more to the point, to make it trivial it will not be cheap
Of course you could and should go with propane or natural gas. When you do that you need to consider ventilation, heat resistant blowers to vent hot air (oh look, another component), burner design or off the shelf burners where you will pay for the privilege of buying a good one off the shelf.
Can you get a roaster that is less expensive? As a matter of fact you can....if you have the time and skills to build it yourself. My very first adequate drum roaster used that George Foreman rotisserie drum basket I mentioned. Because it only roasted 5 lb of cocoa, the drum was very light and I could run it off inexpensive slow responding electric burner style heating elements. The enclosure was built out of aluminum sheets sandwiching ceramic hardibacker. To control the heating elements I used a 20 amp Variac (a variable transformer) and the motor was pretty cheap since I bought it from a surplus supply house. Frankly I loved that roaster. I also spend many hours designing and building it, paying for it in a heavy dose of sweat equity and failures as I learned where I could cut corners and where I could not. In the end I had a 5 lb roaster that emitted quite the amount of smoke., I also could not actually measure the bean temperature but it probably cost me in total about $250, half of that being the Variac. You can see the decisions I made and lived with quite happily. But there isn’t the proverbial snowball’s chance in hell I could build it for sale. It was not a death trap, but user friendly and safe it was not. I had to load and unload it with kevlar gloves. The one I built after that is the one I started this article describing and am using to this day....and still use the same kevlar gloves but I’ve since burned out two Variacs.
Before I keep on with memory lane (damn I loved that roaster, but in only lasted about 2 years before the hardibacker crumbled due to the repeated heat cycles [it was cheap but not durable]), let’s keep on with the question at hand.
“ Couldn’t I roast in a pan like they do where they make the cocoa beans. Would you tell me how to do that? Should I use low or medium heat?”
You could....technically...and there is every chance you could hone your skill to do it over a long time and many failures and finally make some really amazing chocolate. And if that makes you happy, by all means, yes, do that. But can I help you take a short cut and tell you how to do it? Sadly not. It isn’t because I won’t, but I literally can’t. That is not my skill set. That is a path you will have to walk alone. Along the way you will ruin a lot of beans. I certainly did learning how to drum roast. That is the price the Iron Triangle will demand. What you will likewise learn along the way is that ‘low or high heat’ is so far away from the reality of roasting that I am at a loss of words to convey how ignorant (really, no insult intended) that question is. To my mind, it is the question of someone trying to game the system. You know by now know I don’t believe that is possible.
Another thing that I want to address is the high reproducibility of drum roasting where you have feedback via bean temperatures. At this point I have taught a few hundred people in person how to drum roast. Most came into the seminar out of frustration. They tried to roast in an oven or in a pan and no matter how many notes they took, and how meticulous they were, making good chocolate seemed like a roll of the dice against the House that nearly always won. After the seminar, time and again, I have been told that I had clarified what was important and what was not and suddenly they were seemingly making great chocolate nearly effortlessly. I don’t think I really did that much. I mostly stressed the need for reproducibility and control and the only way I had of doing that was in a drum roaster with certain features. Once you have that information, you have the winning lotto ticket. Without it you are destined to very slowly dial in a roast and pray no parameters really change or you have to start over. I can’t tell you how many bean to bar makers I’ve spoken to that have regaled me with their tales of needing to use a full 150 lb bag of beans to come up with an acceptable roast profile when using a convection oven. This totally is not to brag but instead explain why I so love drum roasting and my methodology. If I can’t get a good or even great roast the first time I roast a bean, I’m surprised. I’m not that good. It is just that easy.
But this is where we bring it home.
It is easy because the roaster I’m using is not cheap. I have not scrimped on the features I need to allow it to be easy.
At the end of the day, roasting a large amount of beans consistently, time and again, requires a quality build and that really isn’t going to be inexpensive. Aside from a roaster being “only a drum, motor and some heat” you have to think about all the infrastructure that is going to hold that drum, motor and how to deal with that heat long term. Insulation and food safe materials are also very important. Without good insulation your reproducibility goes down and without food safe materials, well, you can’t even safely use the roaster.
So.....
There is one more part to this story I want to relate about roasting that I said I would talk about. Safety certifications and their hidden and expensive costs.
The Behmor 2000 was formally the Behmor 1600 (named for the 1600 watts of power it used if you are curious) and contrary to looking to many like a toaster oven, it is a nice piece of engineering that sells for an amazingly good price for what it is. People complained about the difficulty of roasting coffee in it because it had temperature limits that were put in place in order for it to be safety certified. Over time Behmor was able to increase those limits but was forced to put in a safety feature that triggered an ERR 7 if the person was not at the roaster near the end of the roast. You have to push a button to tell the roaster someone was there. This was the intent because because people were walking away and burning houses down and then suing Behmor because they didn’t follow the manual about not walking away. Time and again people whined that Behmor should have put in a $0.15 beeper. I’m hear to tell you that both that Behmor has now put in that $0.15 beeper (we have the upgrade kits HERE) and it cost them over $150,000 after all the circuits boards were redesigned, the front panel was reprogrammed and all new safety certifications were paid for. I’m just relaying this to you to give you just one example of the hidden costs that go into products that are sold to the public.
This is also why I have yet to bring a 10-15lb roaster to market. On the surface, that beeper was $0.15. In reality it was $150,000. ‘nuff said? Yes, it is a hole in the market.....please feel free to fill it.
To round this out, ff you are building your own roaster, you can indeed cut out a LOT of expense by substituting your own labor and minor inconveniences here and there. You can likewise address many of those inconveniences by having the proper and expensive tools (see, no free lunch) to make your roaster convenient and a joy to roast on. But to expect a commercial roaster manufacturer to make an inexpensive roaster because “they are only a drum, motor and some heat” is missing the reality that a good roaster is a hell of a lot more than that.
Happy roasting folks.
Stay tuned for Cracking and Winnowing as the saga continues.