Lots of people—ok, most people—prefer to leave the coffee-roasting to the professionals, which is fair: the act of brewing coffee, actually, is technically “easy” to do, but really difficult to do well. Just about anybody can throw some ground coffee and hot water together and call it a beverage, but there’s some question over whether you’d actually want to drink it. Same thing with making green (unroasted) beans brown. On the one hand, it’s basically as “easy” as making popcorn. (In fact, you can even use the same machine to get the job done: See below.) On the other hand, however, the act of roasting coffee contains in it myriad chemical and physical reactions—most of which can’t be seen, but are only heard or smelled—that are impacted by about a gazillion tiny variables that are very difficult to rein in and master.
That said: Roasting coffee, like brewing it, or like undertaking any new culinary adventure, can be so much fun and such a relatively low-stress hobby that with a few tips and a couple of good pieces of equipment, there’s really very little risk in giving it a shot. (Though you will want to make sure your living space is up to fire code—and don’t even think about trying any of this at home if you’ve got a sprinkler system, unless you want to wind up as drenched as the grounds in your Chemex filter on a Saturday morning.)
Before you get smoky, here are a few tips to put you on the right track to achieving roasted realness without changing out of your pajamas.
Buy decent beans. Thanks to the increasing number of coffee geeks who are dead-set on taking their coffee all the way from green to gulp-able, there are also an increasing number of resources for small-batch unroasted specialty coffees, where a few years ago the options were limited to past-crop dregs, beans of questionable origin ordered from eBay, or semi-underground networks of home roasters in forums swapping supplies. If you’re looking for very small quantities and aren’t too picky about what you’ll wind up with, Amazon is actually a halfway decent resource. If you’re interested in getting serious, however, try a DIY-coffee specialty store like Portland, Oregon’s Mr. Green Beans, or the one-who-started-it-all, Sweet Maria’s.
Invest in a fire extinguisher. No matter the method you use to make your green beans turn brown, you will have to prepare yourself for the possibility of fire. Roasting takes place at very high temperature, and as the coffee gets hotter and the moisture inside starts to evaporate, the beans become increasingly flammable. Fires are preventable by following good roasting instructions and paying close attention—cell phone down, my friend—but only you can prevent roaster fires.
Check your smoke alarms. Where there’s smoke there isn’t necessarily fire, but there will be smoke. You’ll want a good vent, open windows, maybe a fan nearby—and you also might want to take the batteries out of the alarms, just temporarily.
Don’t expect the best. (But don’t expect the worst either.) As mentioned above, roasting at home is completely doable, and with practice (and the right beans) it’s absolutely possible to achieve something really surprisingly good. There’s nothing like making something magic happen with your own hands in your own kitchen, and coffee is just short of alchemy, after all. Write down your technique and your results, keep good notes about time and temperature—you will want to time your roasts to see how evenly the heat is being transferred and absorbed, and to keep track of the “cracks,” or the audible signals the beans will give you to indicate how you’re progressing.
Let it rest. Just like with bread fresh out of the oven, it’s tempting to dive right in and start tasting the fruit of your labor right away—but trust us, it’s worth the wait. Coffee is very busy off-gassing, or releasing carbon dioxide gas, from the moment it is finished roasting, and will continue to release that gas very aggressively for the first 12–24 hours. For the best brewing experience, the vast majority of coffee professionals recommend letting the coffee “rest” for at least a day before attempting to make a drink out of it; if you rush your beans, you might end up with a bitter cup that doesn’t properly show off your handiwork.
Here are some different ways you can achieve that just-roasted coffee taste in your own kitchen (or backyard).
Before you buy the beans and fire up the stove, you’ll want to give yourself a little bit of know-how regarding what exactly happens when you’re roasting coffee, and how to generally achieve the best results. You’ll need to know that coffee typically roasts at very high temperatures, that there will be a somewhat slow development for the first five to seven minutes, and after that things start to snap, crackle, and pop pretty quickly. (Literally, actually: Roasters use points in the roast called “first crack” and “second crack” to determine and describe how dark the coffee is roasted. All coffee will make it through first crack if you’re successful, and most folks who like a medium roast will stop the process before second crack happens—so you’ll want to know what to look and listen for here.) See the overview.
Friends and family during a coffee ceremony in Ethiopia and cowboys huddled ’round a campfire both drink coffee made this same way: Simply toss some green beans in a pan and hit ’em with heat until they’re done. (Don’t forget to stir and shake them around, though, or you’ll get a scorched mess.) This recipe utilizes the high, direct heat of a grill, but you can get roughly the same results with a gas stove. See the tutorial.
If you’re a little spooked by the open danger a cast-iron skillet offers, you can go closed with an old-fashioned hand-crank popcorn popper. You can pick one up for around $35–$40, and make sure to look for one with a sturdy, heat-resistant handle and a heavy bowl to retain the most heat. See the tutorial.
A perfect marriage of the first two options is the rotisserie coffee roaster that can be attached to most outdoor grills. You get a nice even roast from the rotation of the beans over the flame, it’s a touch safer than roasting in an exposed skillet, and you can keep things outside when they get smoky. (Probably don’t want to throw any brats on the grates below the coffee, though, unless you want your morning cup to taste like a one-mug breakfast.) See the tutorial.
The first step to becoming a full-out roast-your-own-coffee nerd is to pick up an air popper at a yard sale or a thrift store and quickly convert it to a home coffee roaster. Air roasting is a really great way to achieve a slightly more even (and less labor-intensive) batch of beans than the methods above, though vintage popcorn poppers don’t give you terribly much control over the process. See the tutorial.
The next step on your journey to full-on DIY coffee roasting geekdom is to drop a little dough on a good, reliable starter model. There are so many online resources from home roasters offering tips, tricks, and other unsolicited advice, that you will find yourself in very good company as you try out your first batch (or your first hundred batches). See the tutorial.
If you are ready to get high-tech and low(ish) maintenance, you can’t beat a fully programmable, highly consistent, control-from-your-iPad gadget like an Ikawa sample roaster. While it’s designed to roast 30–50-gram batches for cupping and sampling for sensory analysis in professional settings, turns out that’s just enough to roast tomorrow’s coffee today. (Remember you want to let the beans rest overnight.) What could be more luxurious than knowing you roasted this morning’s coffee yesterday with the touch of a $1,500 button?
— Head photo: Vimeo.