Roasting Coffee at Home: a Beginner’s Guide
Roasting Coffee at Home: a Beginner’s Guide
By: Matthew Miller
Why Roast Your Own Coffee?
Roasting coffee is one of the easiest steps towards more self-reliant living. Unlike other self-sufficiency projects, it’s a low-cost, low-hassle project that will save money while also improving the quality of every morning brew. With a little know-how and a few small purchases, it’s easy to begin creating gourmet roasts and blends.
Home-roasting coffee is so easy that until the twentieth century and the rise of the convenience-food industry most people roasted their own coffee beans. As Kenneth Davids explains in his introduction to the topic, Home Coffee Roasting: Romance and Revival, the history of roasted coffee beans began at least as early as the sixteenth century, and from that time until the end of the nineteenth century, most people either roasted their own beans at home or had them roasted in small batches at local shops or by wandering roasters. Small appliances for roasting coffee in a wood-burning stove or over an open flame were common; the coffee could also be roasted in a normal pan. In some African and Mediterranean countries, the practice of home roasting remains commonplace in a continuation of the tradition reaching back to the origins of the drink. But in most of the Western world, people fuel their desire for caffeine with inferior pre-roasted beans.
Today’s norm in America: the pre-roasted bag purchased in a grocery store, is a relatively recent innovation. At the end of the nineteenth century, companies such as Arbuckle Brothers began roasting coffee in massive batches and advertising it as the “modern,” “sophisticated,” way to buy coffee. Like many other foods—bread, pasta, and condiments—coffee became something that was purchased ready-made, rather than being made in the home. And with this greater convenience came a corresponding drop in quality. In order for pre-made products to be affordable to ordinary people, manufacturers had to find ways to cut corners using industrial techniques that were inimical to quality. Like any mass-produced convenience product, this coffee is both more expensive than home-roasted beans and inferior in flavor—yet thanks to sophisticated marketing and the twentieth century’s turn away towards pre-made foods, it has achieved market dominance. The obsession with convenience food bred into Western people by the culture and industry of the twentieth century has claimed another victim. Although coffee roasting is seeing something of a renaissance today as DIY culture returns to the mainstream, it remains a marginal activity. Even self-proclaimed coffee snobs, though they may grind their own coffee and brew it in fancy equipment, generally buy it pre-roasted.
Yet the case for roasting coffee at home remains very strong: even now, the best coffee is roasted in small batches only a day or so before it is brewed. The stuff bought at the grocery store, in contrast, is weeks old at the least, and has been roasted carelessly in huge industrial roasters. This leaves the buyer with a choice between paying premium prices for a fresh roast at Whole Foods or a gourmet shop and buying stale industrial coffee. Roasting coffee at home, though, allows for fresh, gourmet coffee without paying high prices. Roasting coffee for a household may take as little time as ten minutes a day. And in return, coffee lovers get a brew on par with the best coffee shop in the neighborhood, often at roughly half the price.
Choosing a Roasting Method
The first step toward roasting coffee is to pick a roaster or roasting technique and learn how to use it. A variety of options exist, with varying difficulty and expense: they range from roasting in an ordinary oven or wok, using to expensive appliances designed for home roasting. All of these options have their advantages and disadvantages, and each bears consideration before making a choice.
Oven Roasting. Coffee beans can be roasted in a perforated pan like a vegetable steamer or metal colander in a gas oven. It does have to be a gas oven: according to the best coffee roasting site on the web, Sweet Maria’s (sweetmarias.com), electric ovens produce roasts which are far too uneven to taste good. This is perhaps the most economical way to try home roasting, since there only a few common kitchen items required. However, there are several downsides to this method: the roast is uneven, it is difficult to observe how the roast is progressing, the beans must be watched constantly and stirred frequently, and the chaff and smoke produced by the roasting beans will make a mess of the oven and possibly the kitchen.
Stove-top Roasting. It is also possible to roast coffee on top of the stove, using a skillet, a wok, or a stovetop popcorn popper like a Whirly-Pop. Like the oven method, this is economical and easy to try, but not ideal from the point of view of roast quality or cleanup. For best results, use a peaberry coffee, the round beans of which will roll around and thus roast more evenly. Although this method might be fun to try, it is not recommended due to its inconvenience and mess.
Home Roasters. Numerous appliances designed for home roasting are now available for purchase by those who want to get serious about their coffee. These roasters are essentially small-scale versions of professional roasters, in both the “air roaster” style (the beans are tossed and roasted by hot air) and the “drum roaster” style (the beans roll around in a rotating, heated metal drum). These produce a highly consistent roast, with little variation from bean to bean—a professional quality roast, really—and can often roast larger quantities than allowed for by the other methods. These produce the best possible coffee, but since they run from $150-$1000, beginning roasters may want to hold off until they are sure they want to make the investment.
Air Poppers. Hot air poppers are easily available and not expensive, and produce the best results of any method besides appliances designed for roasting coffee. The only downside is that it can only roast about half a cup of coffee at a time, and the popper must cool down between roasts. The right air popper will toss and roast the beans, keeping them in the popper’s chamber while venting the chaff neatly into a bowl placed under its chute. It will take about ten minutes (give or take) to fully roast the beans and requires minimal supervision and no stirring in order for the roast to turn out even. Sweet Maria’s provides a list of poppers that are known to work well—the main criterion is that the popper’s chamber uses side vents to let in hot air rather than a wire mesh. Poppers with mesh at the bottom can catch fire while roasting coffee, so make sure to get one with vents instead. The forums at Sweet Maria’s are a great resource for finding out details about the pluses and minuses of various poppers, although the West Bend Air Crazy is high recommended. (Apparently the West Bend Poppery II, which is no longer being made, works even better—so dig out the pantry or keep an eye out at the thrift stores.)
Buying Green Beans
In addition to the equipment for the chosen roasting method, beginning roasters will also need to purchase green coffee beans. Although they are not something that can be picked up at the corner store, green beans are more accessible and affordable than most people think. In general, green coffee beans will cost anywhere from $5-$8 per pound, though this cost can vary depending on the type and quantity. In some cities, there may be specialty stores that sell green beans, or a deal can be made with a coffee roaster to make a purchase from their supply. (These folks will undoubtedly also be a great resource for other information about roasting as well.) It is also easy to find beans online: Sweet Maria’s is a great supplier, or try looking at the selection on Amazon. The variety available is staggering, and those who want to pursue coffee knowledge as a hobby akin to that of wine aficionados, can look to Davids’ book for a thorough education on the regions and types of coffee. When just starting out don’t worry too much with the type—any home-roasted coffee will be so fresh that it will taste delicious in comparison to the old pre-roasted stuff.
Roasting with an Air Popper
Once a popper and come green coffee beans have been acquired, the roasting can commence. With a hot air popcorn popper, this is a relatively simple operation that nonetheless requires some know-how and experimentation. Because these poppers are cheaply made, even two of the same make and model may roast differently, so a process of trial and error is inevitable.
Place a large bowl under the chute of the popper to catch the chaff, and measure out the green coffee: use the same volume per roast as the manufacturer suggests for popcorn, usually about half a cup. For the first few roasts, it might be worthwhile to skimp a little on the beans—a smaller batch will generally roast more evenly and quickly, and once a couple of successful roasts have taken place, the upper limits of its capacity can be tested. A bowl of some kind to cool the beans is necessary – it must be something that will help them release their heat—a metal colander is one good option, although an aluminum pizza pan works as well. Keep two pot holders and a wooden spoon on hand. Make sure to open a window and turn on the kitchen exhaust fan.
Place the beans in the chamber of the popper, make sure the chute is secured, and turn on the popper. If beans escape out the chute, replace them carefully. Keep an eye on the beans in the chamber and make sure that they are moving around to ensure an even roast. If it looks like some are getting stuck, carefully (using the pot holders) open the top of the popper and give the beans a stir with a wooden spoon from time to time.
After three to four minutes, the beans will begin to smoke and make a crackling noise. Chaff may also begin blowing out the chute. This is referred to as reaching “first crack,” and is the point at which the beans begin to reach a drinkable roast. Once the cracking has subsided, wait about another minute for a very light roast, or two to three for medium roasts. Beyond five to six minutes of total roast time, you will begin getting into dark roasts. Somewhere around the eight or nine minute mark, the beans will crack a second time, at which point they have reached an extremely dark (Espresso or Italian) roast. Shortly after this point they will begin to have an unpleasant charred flavor, so don’t go much beyond “second crack.” It helps to have a sample of a much-loved roast that handy so that the color can be matched.
Once the beans have reached the chosen roast stage, turn off the popper and pour them out into the cooling pan using the pot holders. Place the pan under the exhaust fan or by the window and stir the beans with the wooden spoon until they have cooled off enough to touch. They will continue to shed chaff, so do this over the sink or the chaff bowl. Don’t neglect this step: without being cooled, the beans will continue to roast internally until they are darker than desired and will lose flavor and aroma in the process. The idea here is to cool the beans off as quickly as possible, within two to three minutes, while also keeping them moving. A spray bottle of purified water can be used to cool them off more quickly—consult Davids’ book for more information on this technique.
Once the beans are cooled, they will continue venting carbon dioxide for up to twenty-four hours. They need to be left in the open for at least four hours, and it will do them no harm to sit uncovered for longer. During this four hours, the aroma of the beans, which will have been smoky or grassy while roasting, will change to smell more like how coffee usually smells. When storing them, mason jars or canvas bags are good options—avoid plastic. Freshly-roasted beans can be ground and brewed as soon as the four hours of resting are up, and they will be at their best for twenty-four hours after roasting.
Finessing The Roast
When roasting that first batch of coffee beans, the best procedure is not to worry too much about the specifics of a roast: as mentioned above, try matching a roast or experimenting with different roasting times. However, it is worth knowing some of the lore related to different roast styles. A general knowledge of these classifications will help to determine more precisely which roasts are liked and how to compare them. These classifications have never been standardized, and different naming systems and definitions proliferate. For a beginning roaster, however, Davids’ book provides a simple classification using the terms that are seen most frequently on commercial roasts. Here it is, from lightest to darkest, and with estimated (and highly speculative) roast times:
New England (light brown bean, dry surface; just after first crack)
American (medium brown, dry surface; 1-2 minutes after first crack)
Viennese (medium dark brown, flecks of oil; 2-3 minutes after first crack)
French (moderately dark brown, oily surface; 3-4 minutes after first crack)
Espresso (dark brown, oily surface; 4-5 minutes after first crack)
Italian (dark, blackish brown, very oily; at second crack)
Dark French or Spanish (almost black, very oily; 1 minute after second crack)
Bear in mind that these labels and roast times are approximate and highly changeable—a roast that one coffee shop considers Italian may taste like French or Espresso, so experiment. The labels are useful, though, in helping to make comparisons and talk to others about roasts. Other labels that are sometimes seen used by home roasters are the classifications City, City Plus, and Full City, which correspond roughly to the Viennese, French, and Espresso/Italian roasts.
Brewing and Enjoying Home-Roasted Coffee
For best flavor, make sure to drink the coffee within twenty-four hours of roasting. Once the decision has been made to home-roast coffee all of the time, invest in good brewing equipment, for example, a French press or other quality brewing system (most automatic drip coffee machines will not do gourmet coffee justice), and possibly a burr grinder. It would be a shame to go the trouble of roasting coffee and then to destroy its flavor by using an inferior brewing method, so it’s worth investing in the right equipment. French presses cost as little as $20 and the difference in the taste they produce can be shocking.
As experience is gained in home-roasting coffee, there are two routes that can be taken: continue the coffee education and become a true coffee geek, or embrace coffee roasting as another simple way of saving money. Although the current hobbyist culture often gives the impression that any given project must be mastered in all its complexity, roasting coffee is not like that. If one doesn’t want to invest the time and energy to become a coffee aficionado, it is perfectly reasonable to see home roasting as simply a way to get a fresh product and save money, without going overboard and memorizing all of the complexities of different beans and roasts. Like so many other DIY projects, roasting coffee can be as involved and specialized or simple and economical. Roasting coffee is only a difficult task for those unaccustomed to doing anything for themselves. Home roasting can be a simple addition to any repertoire of self-sufficient tasks.