When I first started roasting coffee it was on a table top coffee roaster. Roasters like this can cost around $500 and a miniature version of the coffee roaster that I use now. I made mine for under $75. Here’s how.
What do you get when you cross a popcorn popper and a Turbo Oven? You guessed it, a coffee roaster.
A coffee roaster is a spinning barrel that moves the green coffee means around while hot air is blown across them. That’s it. So the first thing you have to do is order a Stir Crazy popcorn popper (flat bottom heater with a rotating agitator) and a Turbo Oven (table top convection oven). While the popcorn popper and oven are in transit, go to your local hardware store and get a spacer for central heating ducting, a bolt, a few washers and 2 nuts. When the popcorn popper arrives...throw away the lid and remove the heating element from the bottom portion. Also remove the plastic rod that attaches to the motor in the bottom portion and replace it with the bolt, washers and nuts. Fasten the stir rod to the new metal bold assembly. When the Turbo oven arrives...throw away the bottom part. Adjust the metal spacer so that the popcorn popper and turbo oven are about 1-1.5” apart. Punch holes or make fins in the spacer. The reason will be clear later.
You now need to find an old fan, a colander, a wooden spoon and order beans.
Once you have all your items you’re now ready to roast coffee. Arrange the fan so the fan is face up, parallel to the floor (outside is preferred unless you don’t mind sweeping). Plug in your popcorn popper, place the spacer on the popper and the turbo oven on top of that. Turn the timer and temp to max and let the heater come to temp (around 15 min). Once the green light on the Turbo oven is on, lift the lid and dump in around 100g of green coffee. Replace the lid and start a timer. You can watch the beans change color from green to yellow to brown. Once they turn brown, you’ll start to see the chaff start to come off the bean. This is why you added holes/fins to the spacer...and why you’ll probably want to do this outside. The chaff will start to fly out of the roaster and go everywhere so you’ll probably want to have a broom and dustpan handy. With this method you’ll probably only be able to roast to a few minutes into first crack.
When your roast is ready, turn on the fan, grab your colander, remove the lid and spacer, dump the beans into the colander, place it over the fan and start to stir the beans with the wooden spoon. You’re doing two things here, 1) you’re cooling down the beans to stop the roasting and 2) you’re removing the chaff from the beans. Once your beans are cool and clean...they’re ready to grind and brew.
Even though this is a crude method, you can taste the difference compared to even the whole beans you get out of the bulk bins at the store.
Here’s a link to the site where I got the instructions. It has a fill parts list and pictures so that you can do this yourself. Enjoy!