Roasting Coffee with a Hot Air Popper

If you are looking at this page, you are likely new to the idea of roasting coffee.  You may want to look over the roasting basics page.  You don't necessarily need to memorize the names of the roasts, but you do need to know what roast level you are aiming for, and what the roasting process leading up to that roast level is.  I also need to make one disclaimer--a hot air popcorn popper is designed to pop popcorn, not roast coffee.  If your unit gets damaged while roasting coffee, it is being used for a purpose for which it was not intended and your warranty (if you have one on it) is likely to be voided.  With that out of the way, let's move on.

First take a look at your popper.  Does it have a screen in the bottom, or on the sides?  The preferred poppers will have a screen on the sides of the popping chamber. (mine doesn't)  If yours has a screen on the bottom like mine does, it will still work, you just need to exercise a little caution.  Coffee beans when roasted give off chaff--that's a papery covering over the bean that blows off.  This chaff can collect in the bottom of the popping chamber and if left there can start on fire when the popper is run.  I simply make sure the screen area is clean after each roast.

So, to start roasting:  You will need a hot air popper, a bowl or something to catch the chaff in, a pan or something to put the roasted beans on, pot holders to handle the hot chute on the popper, and a watch with a second hand to time the roast.  I also found a glass chimney from a kerosene lantern that fits my popper nicely that I use instead of the chute that came with the popper--it minimizes the unroasted beans being blown out of the popper during the roasting process, and gives me a better view of what is happening with the beans.

One note: you may want to do this in a garage, or outdoors because there is some smoke that comes off roasted beans, and the aroma is fairly strong.  It isn't necessarily an unpleasant aroma, but my garage smells of roasted beans for quite some time after I roast, and you may not want your entire house smelling of roasted coffee for the whole day.  Also, when the chaff blows out of the popper, I simply brush it onto the floor, and sweep it up when we sweep out the garage.  If you do this outside or in your garage, you will have to make allowances for colder weather.  Things will take a little longer. 

Getting started:  Plug in your popper without the top on it and let it warm up.  In colder weather, this may take a little longer.  I usually let mine run for 45 seconds to a minute in cold weather, 20 -30 seconds in warmer temps.  When it is hot, put the beans in and put the top on and plug it back in.  I find that 1/3 cup of beans works very well.  Don't overload the popper.  You may need to shake the popper a little at the start to get the beans moving.  It is important to have the beans moving.  If they don't, you will have burned spots on some of the beans and will get an uneven roast.

At about 2½ to 3 minutes, you will start to hear the 1st crack.  It will sound just like popcorn popping.  It will diminish after a minute or so.  After the 1st crack, begin watching the color of the beans closely.  You may or may not hear the 2nd crack.  (When I roast Guatemalan decaf, I don't hear the second crack, when I roast the Tanzania Peaberry, I do)  I have found that I am usually done anywhere from 6 to 8½ minutes, depending on the roast level I want and the ambient temperature.  (This isn't a set it and forget it process--you need to stay with it) 

When the beans are roasted to the desired level, unplug the popper and pour the beans onto your pan.  The beans will be very hot, and as long as they are hot they will continue to roast, so they need to be cooled relatively quickly.  I achieve this by putting them on a metal pan and placing the pan in my refrigerator for about 5 minutes or so.  (One of the advantages of using an actual coffee roaster such as the i-Roast 2 is that they have a built in cooling cycle)  There will likely be some chaff mixed in with the beans on the pan.  I simply take the pan outside and lightly blow on it and the chaff blows away. 

When the beans are cooled and here I mean just to room temperature, place them in an airtight container--I use a glass jar with an airtight lid, and place them out of direct sunlight--either on your countertop or in your pantry. 

There, you're done and in a few hours you can grind up and brew the best tasting coffee you have ever had!

Ready to get started?  Click here to get your coffee beans.