Roasting coffee with a popcorn maker is unbelievably easy. And you can roast your own 'single origin' or espresso blends for a fraction of the cost that the specialty roasters charge.
Everthing I know about home-roasting I owe to Sweet Marias. They have a wealth of information on their site, but the main info is here on this page.
This is my popcorn maker - a Breville 'Crazy Popper' which I picked up at a tip shop for less than $5 AUD.
I bought green beans from Tascaffe (a local roaster, based in Derwent Park, Hobart) for $12/kilo. I bought three varieties: Ethiopian (unknown region), Blue Batak (indonesian) and Nicaraguan.
I asked Nick from Tascaffe for a few blending tips and he suggested I mix the Ethiopian & Batak 50/50 to get a slight chocolatey flavour.
My aim is to make a blend that is lively and flavoursome enough for me to drink as a straight espresso, but one that works well with milk for the rest of the family to drink. The Ethiopian on it's own is too acidic and dominant when used in a latte.
I had previously test-roasted each batch of beans to first crack. They took almost the same amount of time so I decided to do something I hadn't done before when making a blend - I mixed the two varieties as green beans and roasted them together.
Here are the mixed beans ready to go in the popcorn maker. The machine comfortably takes just over half a cup. I can squash more in at the pre-roasting stage but then I just end up with overflowing beans at the end.
I use the stopwatch on my phone to time the roast, but I also keep an eye on the colour and an ear on the sound. After about a minute and a half the coffee begins to colour.
First crack started soon after 3 minutes. I turned the machine off after most of the pops had stopped (like you would do with popcorn) at just before the 5 minute mark.
Then I quickly pour the hot beans out on to a metal tray covered with baking paper to start cooling.
As the first batch is cooling. I reset my timer, and load up the popcorn maker and start the next batch of green coffee. About half way through the roasting time, I move the cooling roasted coffee from the tray in to a plastic container.
I usually wait until the following morning before putting the coffee through the grinder and then espresso machine.
As a double-espresso shot the blend is lightly acidic and lemony, then creamy and rich with hints of vanilla and caramel. It finishes with a slight chocolate and spice flavour.