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Photo: Ariel Zambelich/WIRED
Home roasting is the pinnacle of coffee geekdom. You get to pick exactly where your coffee comes from, choose the roast level, and enjoy it fresh, knowing not only what day it was roasted, be also what time. For beginners, the hand-cranked, stovetop Whirley Pop popcorn maker can be hacked into a bare-bones coffee roaster. For budding home roasters, this cheap mod is an excellent place to start. You can make the roaster as precise or as low-key as you want — either way, it has the potential to make some great coffee.
A huge array of literature has already been generated on the subject of Whirley Pop hacking. I've read about folks welding a drill bit to the hand crank, or creating a shop-vac-powered rapid cooling system. I opted for one of the simplest "Frankenroaster" hacks: punching a hole in the lid of the Whirley Pop to install a digital thermometer.
As easy as the hardware modification is, keeping track of the roast while you're underway takes diligence. At the very least, you should monitor your progress and log the roast as you go using a pen and paper. Daredevils will tell you to just wing it, but if you're just starting out, logging is necessary for identifying and correcting mistakes. There are also a couple of apps made for monitoring beans. If you have an iPad running iOS 7 or later, download the $10 Roastmaster app to manually input your temperature as your roast goes along. And at $49 for the most basic monthly subscription, RoastLog gives you a live feed and tracks your roast online.
I used a timer and thermometer to keep track of the roast. To prepare, I read Sweet Maria's roasting guide, studied Michael Sivetz's chapter on roasting in Coffee Technology, and asked for advice from some roasting professionals.
To see how the DIY roaster performs when compared to more expensive home-roaster appliances, read our coffee roaster review roundup.
What you'll need:
- 6-Quart Whirley Pop, $27
- Digital Thermocouple, $30
- Timer
- A good scale that can measure grams. I recommend this one ($90), though cheaper options are fine
- About 8 ounces (226g) of high-quality green beans
- Hammer
- Nail
- Wood
- Stovetop
- Metal colander (or two)
- Safety glasses (just in case)
All photos: Ariel Zambelich/WIRED
