Absolutely! I'm not sure when I'll have time to get back to work on it, but I'm hoping to in the next few weeks. I'll let you know when it's ready.

Once you get it up and running i've love to come by and take a look at it if that's possible.  I'm not all that terribly far away i suspect.  Always fun to see operational stuff!

Very interesting! I will definitely look into this and see how I could best add it. My roaster will be relatively open, so building up pressure isn't going to be a problem. 

Lots of things you can do once you've got the ability to do that - industry uses it mainly to achieve better micro kills at lower temperatures/times (steaming it).  You can also use it to modify flavors (both removing and creating new flavors).  It opens up a level of control and flexability for formulation that you currently likely don't possess.   Depending on how you use it (ie if you end up using it in a fashion where you create a lot of steam), you may need a pressure relief valve so you don't inadvertantly build a bomb.

Thanks eg!

Sebastian: It would be pretty easy to do this. Would the idea be to produce steam? This is something I haven't looked into too much.

Ben - just a suggestion, you might want to consider giving yourself the ability to inject liquids into your roaster, perhaps by running a pipe inside your frame, and drilling spray holes.  The assembly is great to enable that.

Wow Ben, that roaster is impressive, and the conching machine too!

It's probably betweeh $1000 & $1200 at this point. I've got a little more to buy, but mostly it's just finding the time to finish the build.

looks fascinating man. what is the cost of the build?

I've got some photos of the build process up here: https://www.facebook.com/media/set/?set=a.950484961659148.1073741833.124491320925187&type=3

awesome. would love to see what the design/end product looks like. thanks man. appreciate your time.

Some roasters use perforated drums for more direct roasting, as opposed to heating the air and blowing it through through drum. I'm using a perforated drum for the roaster I'm building partly because it's a simpler design.

Im actually thinking of using one of Toper's roasters to roast the cocoa beans.  I guess the standard ones will obviously have the temp output /temp control. what would the reason be for a perforated drum?

Are you asking if the position of the flame will need to be adjusted, or if the output/intensity of the flame? If the output, then yes, you'll need to able to adjust this to control the temperature. If the position,my guess is that it would depend on the roaster, where the burner is, whether the flame is directly heating the drum vs. heating air that is blown through the drum, whether the drum is solid or perforated, etc. etc.

Thank you for the response. Will the flame level need to be adjusted.  According to roasters back here they had to adjust the roaster's flame levels.  Any thoughts?  

@honest-chocolate: I've been using a drum roaster for several years and haven't noticed any fat buildup. I'm roasting whole beans--maybe nibs would have this problem.

You'll at least need to have a low enough drum speed to not break the cacao, but adjustable drum speed isn't absolutely necessary. That being said, you can affect the roast through modifying the drum speed, so adjustable drum is preferable.

Stainless steel is not a necessity. I did a lot of research into drum material for a roaster I'm currently building and most of the roasters I looked into use a mild steel drum. Apparently, stainless does not transfer heat as well as mild steel.

To your last comment about roasting at a low temp, I'd modify that to say 'at a lower temp than coffee'. I do not subscribe to the 'always roast cacao low & slow' philosophy. It works well for some beans, but very poorly for others. With regards to a roaster, you're going to want as much temperature/energy input control as possible.

anyone used us roaster corp cocoa roasters?  They have dedicated 3kg cocoa roasters (modified coffee roasters) for about 15k.  Anyone know how they perform?

Just a quick question on the coffee roasters being used to roast cocao.  Because of the higher fat content in the bean is there not some sort of build up that needs to be cleaned somehow? otherwise this can have a detrimental affect on the beans?  I have ben trying to get a roaster for 3 months now but opinions vary sooo much.  Hard to get to the facts.  from what i have gathered you need to have drum speed control, a stainless steel drum and obviously you needto roast at a low temp.

Hi Matthew

You can visit our web page www.coffeenutsroasters.com I think Antonino Allegra fro Cocoa Fair gave some idea about our roasters you can roast cocoa in our roasters too

Clay,

I spoke to my roaster manufacturer about the aforementioned modifications. He told me that to have a speed controller on the motor would not be possible, as the motors come standard. However, he said that to change the drum rotation speed, the length of the pulley would have to be changed. In the existing design that he has, the rpm for the drum is 32. Should I take the one he has on stock, or should I ask him to reduce the speed somewhere in the range of 25-28?

PS: My roaster is a 25 kg capacity.

Thanks for your time Clay. I greatly appreciate it!

Luvin

Luvin:

Put a speed controller on your motor and tune it to the speed you need - based on the diameter of the drum you're using and how you're roasting (time/temp). Smaller drums can run faster as the beans are not subject to as much banging around as a larger drum.

Airflow control, conceptually, means having a fan that enables you to blow air through the drum. Ideally, you'd control the speed and temperature of the airflow.

Thanks Ben & Dan for your much appreciated insight.

- Is there an absolute number (in RPM) as to what the drum rotation speed should be?

- Im getting the roaster made in mild steel with the drum contact parts in stainless steel. Should I be going for a complete mild steel body, according to what you are suggesting?

- Can you please let me know more about what you mean when you say 'airflow control'. I'll be able to get this across to my manufacturer, better.

Thank you for your help. I greatly appreciate it!

Luvin

Convection ovens are versatile beasts to be true and I recommend a lot of them into situations where there is no budget for a more conventional roaster.

I would like to add that cooking is also about CONTROLLING heat and airflow.One thing very few convection ovens have is any sort of even the most basic control over the airflow.

Also, not all convection ovens heat evenly from top to bottom, left to right, back to front. One very easy way to see how even your oven is is to put yellow or white cake batter into a sheet pan on every rack in the oven and bake it. Light areas in the top crust indicate places where the oven is cooler, dark brown areas indicate places where the oven is hotter.

Hi Luvin,

We, Coffee-Tech Engineering, have several customers around the world using our roasters for cocoa roasting - on our small capacity roasters and on our commercial roasters.

What Ben writes is true - you'll want to have control over drum speed and thermal behavior. I would also add that drum material is an important factor (we suggest perforated mild steel drums for cocoa) and airflow control is also something that will only benefit you.

- Dan

Hi Luvin,

See Colin's post earlier in this thread. I think the only modifications would be related to drum speed and the ability to roast at lower temperatures. If you can control those two things adequately, a coffee roaster should work fine.

-Ben

Convection Oven.

It roasts 35lbs at a time (260lbs in 8 hours), and does a fine job, provided you place the beans on screens or use perforated sheet pans.

On a smaller scale (Under $30k), there simply is no better solution. On top of that, you can roast your dinner, and cupcakes, and brownies, and coffee, and anything else you like.

Cooking ANYTHING is about heat and airflow. It's that simple. A convection oven has both.

Cheers.

Brad

Hi guys,

I am on the lookout of purchasing a coffee roaster myself. I spoke to the manufacturer about the modifications, and he told me to be more specific and give him technicalities, as to what modifications do I need for cocoa.

Can you'll please suggest the modifications that I am going to have to get integrated on my roaster?

Thank you!

Luvin

www.sevvalmakine.com

[Note from moderator: Rifat appears to work for Sevval, which is located in Turkey. In addition to making coffee roasters they make nut roasters and other machines. This link is to the home page, which is in Turksish. Here is a direct link to the coffee roasters (in English): http://www.sevvalmakine.com/?/en/urunler.html#Coffee Roaster

This is great, thank you for the info. I'll reach out to Erkan and possibly Coffe-tech as well.

All the best.

M

here we go, extract from an email i sent to a The Chocolate Life memebr.:

Absolutely. - In fact, I prefer when people share this kind of stuff publicly on the site rather than privately via e-mail. That way, every member can benefit, including people who didn't know they wanted to know this stuff.

Hi Clay,

i have pics and info about the Roaster, is it ok to post it?

Hi. Just wanted to add a bit from my experience. I'm working at Coffee-Tech Engineering.

We're manufacturers of coffee roasters and we have several customers roasting cacao with our roasters, some with our 2 Kg shop roasters and some with our 15 Kg commercial roaster.

Drum speed and other configurations were set, in advance, to meet the needs of the customers.

I might also add that our shop roasters embed restricted fluid bed roasting and that on our manual roaster all these can be set by the end-users themselves.

Anyway, if somebody wants more information, you're welcome to contact me or just look us up.

Hope I didn't break any ethical rules with this post

Can you post it please so we can all get the info? Thank you.

Great infocan you send me the information on where you got your roaster.

I've looked into coffee roasters too, and the one issue was drum speed. The people I contacted indicated that they could slow down the drum rotation of any size of coffee roaster they sold, but there would be an extra cost.

It sounds to me like Antonino has it dialed in (no pun intended) with the digital drum speed control. Sounds Interesting!

Cheers

Brad

Sorry, continued:

and unless you mess around with the setting you should have quite a even, consistent product.

we roast 15 kg beans at time and breakage is minimal (anyway, you need to winnow!!) with few tricks we manage to extract certain notes that we wish to have.. just a small change on the flame change the taste from hazelnutty to roast almond.

of course there is no limit to perfection and no limit to theoretical roasting and cost involved, but you are also in business to make money..

Hi Matthew, Colin,

we didn't modify the machine.

our roaster is equipped with digital drum speed control, an electronic/digital thermostat, and 3 point of gas/fire adjustment + ventilation valve that we can adjust as well.

we can accurately roast at temp of 120 or 140C quite accurately and unless you mess around with the settings.

Matthew,

You'll find that most coffee roasting drums rotate too rapidly and tend to chew up cacao. I've tried in a Dietrich and a Joper and both produced significant levels of breakage. Also, these machines aren't engineered for the process of roasting cacao, which has different heat transfer characteristics and temperature profiles than coffee, so you'll find it's very difficult to dial back the heaters to achieve accurate temperature profiling without scorching. There's nothing better out there right now than a properly configured convection oven for roasting at that volume unless you have 200k, in my opinion. You can get used gas convection ovens for next to nothing. A spouting fluid bed coffee roaster would be my second bet, but fluidizing cacao requires much higher airflow than coffee, so you're batch volumes would be smaller than rated and you'll still have issues with erratic agitation and breakage. Good luck!

Hi Antonino-

Thanks for the information, did you have to do any modifications to the equipment?

-M

Hi Yes you can, we do roast in a coffee roaster and we do 1 ton a month if not more.

DO NOT BUY AMBEX!!! we have been victim of a fraud directly from them and lost about $5000!!! unfortunately we are in South Africa and is very difficult to fight them. if you want i give you the contact details of the factory in Turkey that build the ambex roasters and get it for a 5th of the price...

the roaster is based on a italian made drum and system and the rest is build in Turkey. decent machine and with a 19kg gas bottle we roast at least 15 bags of beans.

I wanted to see if any chocolate producers have used coffee roasters to roast cacao. I'm looking for a mid-size capacity roaster that doesn't look like a toaster oven and doesn't cost $30K. There are a good number of coffee roasters that are significantly less expensive and are much more attractive.