Introduction: Cheap DIY Coffee Roaster

Hi guys,

this is a short tutorial on how to modify a popcorn maker in order to roast coffee. All you need is

  • a popcorn maker which uses hot air; I bought a Severin 3751 which works fine
  • a piece of copper;
  • raw, green unroasted coffee; I bought it on amazon. I went for arabica beans.

Before you start, please keep in mind that coffee beans and its silver skins can easily cause a fire! So take care!!!

Step 1: Form a Copper Tube

  • take off the plastic top of the popcorn maker
  • take a piece of copper and form a tube
  • put it on the popcorn maker's popping chamber - it avoids that coffee beans spill out during the roast

Step 2: Roasting

roasting is super simple!

  • weigh the unroasted coffee beans; I went for 100 grams raw coffee beans which brings the roasting temperature close to ideal 220°Celsius/425°Fahrenheit. If you take less, temperature will drop. If you take more, temperature will increase. Be aware that the roasting temperature strongly depends on the type of popcorn maker you are using as well as on the surrounding temperature!
  • preheat the popcorn maker and put the coffee beans into the popping chamber
  • during the roast, the coffee beans will start to loose their silver skins. Be aware, that the silver skins can catch fire easily!
  • You select how dark to roast! After a few minutes you will hear the beans cracking. This is the first crack, you may stop roasting. But you can also continue to roast until shortly after the second crack. Check the color of the beansI like espresso, so I went for a pretty dark roast. It took between 15-20 minutes.

  • In the video I opened the bottom of the popcorn maker to increase airflow and avoid triggering the overheat protection. However, this doesn't seem necessary to do.

Step 3: Cool the Roast

  • When the beans get the desired color, stop roasting.
  • Spill the beans in a pot and move it around in order to cool them down.
  • Let it rest for a few hours to get the full aroma.