We Tried Roasting Our Own Coffee. Learn from Us.
Real coffee drinkers roast their own beans. Here's how you can do it yourself.
I’m a sucker for a DIY project. Exhibit A: my dining-room table, which is currently covered in a mealworm-growing operation, because my chickens love mealworms but they cost a fortune at the feed store. Exhibit B: my entire farm, which is nothing more than DIY dreams run amok. So when some lovely strangers on the internet urged me to roast my own coffee beans, I had to give it a try. This had to be simpler than running a farm, right?
Like growing mealworms, home-roasting coffee is a cost saver—at least in theory. “It’s like half the price,” says Byron Dote, the marketing manager for Sweet Maria’s, a company that sells green beans and roasting supplies. What Dote is referring to is the price of the beans, which indeed are quite a bit less expensive than their perfectly toasted counterparts. Sweet Maria’s sells 16 ounces of green beans starting at about $6. I currently pay $16 for 12 ounces of roasted beans from Verve, a roaster based in Santa Cruz, California.
However, you can gobble up potential savings pretty quickly by purchasing expensive roasting machinery. Purpose-built coffee roasters start at about $250 and quickly climb into the thousands. The good news is that you can begin roasting with equipment you may already own. In fact, Dote assures me, if you wanted to, you could do this on your stove with a pan and a wooden spoon.
Most home roasters start with either a hot-air popcorn popper or a stovetop popcorn maker. Since I already owned the latter, it was my method of choice. I watched a few YouTube videos, declared myself an expert, and dove right in, measuring eight ounces of green beans for my first batch.
Things went pretty well at first.
I stirred rapidly in an attempt to ensure the beans browned evenly. Patiently, I waited for “first crack,” which is the sound the beans make when they’ve reached a light-roast status. “Coffee talks to you,” explains Dote, adding that the first and second cracks make slightly different sounds, thereby giving you an auditory signal of when you’re moving from light to medium to dark roasts. “It sounds a bit like a Twix snapping,” he says of the first crack. The next one is more like the snap, crackle, and pop of Rice Krispies.
As I hit first crack, I realized the downside of my new hobby: the smell of roasting beans is not the same scrumptious smell of freshly brewed coffee. It’s sweeter, but in a weirdly off-putting way. And it’s very strong.
I continued to stir, aiming for a medium roast. But right after first crack, my smoke detector decided it had had it with this endeavor. Roasting coffee generates smoke, and even with my stove fan going, there was enough to set off my alarm. No big deal, I thought as I pulled the batch off the stove and took it out to the porch for the final step.
Green coffee beans still have a thin skin on them. When roasted, that skin pops off. Before grinding and brewing, you need to remove this chaff. I laid a box fan on the ground and let it blow up and into a colander filled with the beans. Do not, under any circumstances, do this step indoors, because it is a mess. With a few shakes, though, I had lovely chocolate-colored beans that, after 24 hours of rest, would be ready for brewing.
I could totally do this on a regular basis, I thought.
But then I committed my fatal error: I roasted a second batch, this time taking the beans to a much darker place. My husband loves French roasts, and so I let this second attempt get to first crack, then to second, and then go a minute or so beyond. By the time we got past second crack, my smoke alarm was screaming. So were my eyes and lungs. Smoke was billowing out of the pot. I ran it outside and dumped the beans into the sieve, then had to literally run away—the smoke was that bad.
Here’s the kicker, though: it turns out, the smoke from roasting coffee contains diacetyl, a chemical compound that may cause lung disease when regularly inhaled. In fact, in 2016, the CDC published a notice warning employees at coffee roasters that they might be at risk for lung disease.
Knowing this now, I would not roast coffee inside my house ever again. (In fact, things still smelled pretty bad in my kitchen three days later.) And I would likely not roast without wearing a mask. I also would never take a roast farther than second crack—that’s where things went from mildly to extremely unpleasant.
After I’d smoke-bombed my whole house—resulting in throwing every window open and letting 19-degree air in—I sent my editor a hasty email: “Roasting your own coffee sucks!!”
But by the next morning, I had softened my tone. Freshly roasted coffee is divine. The best way I can describe it is: extremely coffee-y. It’s not strong in the way that word usually means when applied to coffee, like it could strip paint off the walls and rip through the lining of your stomach. It’s just vibrant and flavorful.
The verdict, however, is still out on whether the effort is worth it. Maybe I’d feel differently if I had a true, purpose-built roaster that separated the chaff and minimized the smoke. However, like my efforts into home-brewing beer and making cheese, roasting coffee at home reminded me that there is a reason people pay professionals to do this—and it’s totally OK to leave things to the pros sometimes.
A Super Bare-Bones How-To Guide to Home Roasting
Go outside: Really, learn from my mistakes. Do not do this inside. From here on out, any roasting I ever do will be on a grill.
Find a vessel: I used a popcorn pot, but you can use a pot placed over medium heat; you’ll just need to stir like crazy to keep the beans moving.
Measure: Eight ounces of beans is about all you can do in one batch. More than this won’t roast evenly.
Heat: Using medium heat, begin stirring as your pan heats up.
Listen: First crack sounds like a Twix bar or a match breaking. Second crack is a subtler crackly sound.
Remove from the heat: Personally, I’d never take a batch past second crack again, unless I had a machine helping to control the smoke.
Blow: Set a colander over a fan, and pour your beans into the colander. Turn the fan on, and stand back as the chaff blows away. Shake the colander a few times just to make sure everything is out.
Wait: Freshly roasted coffee will “off-gas” for a while after roasting. It’s best to wait 24 hours before using it.
Brew: And be happy you went through all that work. (Or not.)