Home coffee-roasting results

Now that I've tried to roast my own beans and had a cup of coffee made from those beans, it's time to review the results. But first, I'd like to show you my popcorn pumper making popcorn. If you get an air popper from the thrift store, it's probably a good idea to try and make popcorn with it first to make sure that it works.

Ok, so now that you know that I used a working popcorn maker, here are the results of my coffee-roasting experiments.

Trial 1:

my set-up on the balcony

Bag of green Sumatra beans

I took the scrap beans from the bottoms of the three burlap sacks and topped them off with the Sumatra Mandheling beans. The popcorn pumper has a half-cup measuring scoop that's also part of the cover. I used that to measure 1/2 cup of green coffee beans to use. Since I didn't want my whole apartment to smell like roasted coffee, I did this outside on the balcony by plugging the machine into a power strip, which was plugged into the wall just inside the window. This turned out to be a good idea because the chaff that went flying made a bit of a mess. The mistake was leaving the cover off the popcorn pumper. This meant that the temperature did not reach the right temperature and the beans didn't get to a nice color, even after 12 minutes. So, I cooled them off anyway. I went into the kitchen and thought that putting the beans on a sheet and toasting them in the toaster oven might be a good idea. I did that for about 5 minutes (until I heard some crackling sounds) and took them out to cool. That's how I roasted the beans you see in the picture below. As you can see, it's a light roast.

Fresh light roast, smelled great after 24 hours.

Nice thick layer of crema on top

Fresh espresso with thick layer of crema

The next day, I brewed this in a simple Cuisinart 4-cup drip brew machine with a paper filter to taste "normal" coffee. Then, I brewed a crema coffee with my espresso maker. I added soy creamer to both. The regular coffee tasted like Dunkin' Donuts coffee, which is pretty good when it's fresh. However, I usually drink a dark roast, so this was just not to my liking. The crema coffee was very nice with a thick layer of crema (check out the pictures above). However, the next time, I will try to roast the coffee a little darker, maybe until I see some oils on the surface.

Trial 2:

This time, I put the cover on the popcorn pumper and went on the balcony again. It was a little warmer outside, so I was hoping that using a cover and the warmer ambient temperature might help me create a darker roast. I also decided to take my camera outside and film the process at intervals. I didn't film the whole thing because watching coffee roast is like watching your dryer spin your clothes around and around. It's not great footage. Here's a video summary of what I did:

Even though the weather was better and I got the roast a little darker in the popcorn pumper, I didn't want to wait around for more than 20 minutes. So, I finished them off in the toaster oven again for a few minutes (until I started hearing crackling and saw a bit of smoke coming out of the toaster oven) and got some dark oily beans. As you can see in the picture below, I got a "mixed" or uneven roast, meaning that some beans were roasted darker than others. I'd also like to caution you that the smoke doesn't smell great. If you try the toaster oven finishing method, make sure the windows are open. The whole process of roasting coffee does not create a nice smell for your home. It's not awful but it's not the same smell as you get when you grind the finished beans, which smells great.

Uneven roast

Uneven roast on the left (Trial 2), light roast on the right (Trial 1)

Trial 2 roast on the tray, Trial 1 roast in the jar

Trial 3:

After reviewing the video of the roasting process in trial 2, I thought that the beans might have been spinning a little too quickly. So, for this trial, I decided to add more beans, until they spun a little slower in the popcorn pumper. It turned out very nicely this time and I did not have to use my toaster oven. I got the beans to a nice dark roast but not enough to get oils. The solution for getting a reasonably even dark roast was to put more coffee in the chamber - up to the point where the metal meets the plastic (in the Popcorn Pumper). However, it was not much more than the 1/2 cup that I used in Trial 2. Maybe 1/4 cup more was all that I needed to put in. The whole roasting process took about 13 to 14 minutes for a medium-dark roast with no oils on the surface. After roasting, the volume came to about 1 cup. Here's a short video of the roast:

This video is also featured on Popcorn Hot Air Popper