How to Roast Coffee Using an Electric Popcorn Popper

The next method of home roasting we’ll look at is the use of an electric popcorn popper. This is the easiest method for a beginner to achieve great tasting coffee with more consistency and less practice. It also has the advantage of blowing the chaff out of the beans automatically. Additionally, electric popcorn poppers can be regularly found at thrift stores for $2-$5. The most popular type of popper for roasting is the West Bend Poppery II, but any type of popper with the correct hot air inflow (see below) will work.

There are two VERY important things that must be kept in mind when using this roasting method:
First, though they work well, electric popcorn poppers are not designed to roast coffee. So, not only will it void any warranty you may have on your popper, but also it is not uncommon to burn out the motor after 20-50 roasts. Also, not all poppers have the ability to roast coffee well. As the motors slowly degrade they will become unable to maintain the high levels of heat necessary for roasting so you may have to try multiple poppers to find one that works well. The voltage in your homes outlets can vary from time to time and this can also affect your ability to get consistent results (some more advanced home-roasters use a voltage variac machine to achieve constant power. These machines also allow you to adjust the voltage going into the popper which can give you greater control over the roast).

The second thing to remember is that the popcorn popper MUST have the correct air inflow chamber. THIS IS CRITICAL! Hot air must enter the roasting chamber from the SIDE walls of the chamber NOT FROM THE BOTTOM! If you attempt to roast coffee in a popper with the incorrect hot air inflow you are at great risk of causing a fire.

To begin you’ll need:

  • Electric popcorn popper with SIDE ENTRY hot airflow.
  • A metal colander for cooling the beans.
  • Oven mitts or gloves.
  • A bowl to catch chaff blowing out of the popper.
  • A wooden spoon for stirring the beans while roasting when necessary and for cooling.
  • About a half cup of green coffee (use whatever the recommended volume of popcorn for the popper is).

Start your popper and place the chaff collection bowl under the opening of the popper (this bowl will not only collect chaff but also any stray beans that may pop out during roasting). Slowly fill the popper with the recommended volume of beans (usually about ½ cup). As the hot air begins to circulate, the beans should rotate a bit with the flow of air. If the beans do not rotate at the beginning, give them a gentle stir with the handle of your wooden spoon until they begin to spin on their own.
As the roasting begins, chaff will separate and fly off the beans and smoke will appear.

When the smell of the smoke changes from ‘baking bread’ to coffee and the beans start to crackle, begin to pay close attention and be ready to cool your beans when they have reached the desired roast.

Any time after the cracking begins you can cool the beans, but the longer you go the darker roast you’ll get. Don’t forget to allow for one to two minutes of cooling time when the beans will continue to roast on their own.

When you’re ready to cool, stop or unplug the popper and IMMEDIATELY pour the beans into your metal colander and stir vigorously for a minute or so or until the beans are cool to the touch. Any remaining chaff can also be removed at this point by simply blowing on the cooling beans.

When you are done roasting, wipe out the popper with a dry cloth to prevent the build-up of oils that can not only slow down your next roast but also creates a fire hazard.