As the Germans would say “Why make it simple, when you can make it complicated?”.

The idea was to take a simple popcorn maker and make it into a coffee roaster.

The popcorn maker is the perfect introduction into roasting your own coffee beans.  What we intended to do was turn it from an introduction machine into a regular roaster that is fully programmable and also a start to finish roaster, what I mean by that is that you put the green beans in, set the program you want and when it’s finished the beans will have cooled and are ready to package up.

Testing day was 13 April, it was still out of it’s box so the comment was “do not touch anything but the knobs or you will die” Cheesy


Timing and heating conditions of roast.

190 to 12 minutes

220-225 to 18 minutes
First crack
We got smoke, this is the second time I have ever got smoke, I could see a slight haze in the air, I could certainly smell it.

230 to 22 minutes
I thought this had gone on long enough and literally the second we stopped it, it hit second crack.

I honestly didn’t notice any smell while cooling the beans.

Here are some photos.


No flash

I then packed the beans away in their little tubes and hey presto as I’m pouring them in I get this sweet smell, I thought no way, lifted the beans to my nose and wow they smell Smiley it was/is a light, sweet cocoa smell.

The house still smells of the sweet cocoa an hour later.


It is now in it’s box and almost all put together, it has it’s own power supply, still plugged in to a power point though.

Here is an updated photo of what ‘the box’ looks like.  It still isn’t finished with the addition of a power off/on switch needed, the temperature gauge being hooked up and the programming section defined and in action.

As you can see it is an ‘in action’ shot, showing the temperature it can get up to, 222 degrees Celsius, it does go higher but for roasting coffee beans that is about the most I’d want.


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