Quick Guide to Home-Roasting Options and Procedures
Here are instructions for most of the ways it is possible to roast coffee at home, starting with manufactured-from-scratch devices and moving on to improvised methods. Near the end of this section (here) you will find directions for two procedures related to improvised roasting methods: water quenching (accelerating the cooling of hot beans with a fine spray of water) and winnowing (separating chaff from roasted beans). A brief note about roasting decaffeinated and other specially handled coffees (here) concludes the section.
For background and overview on these machines and methods and their associated processes see Chapter 5. For ideas about things you can do to your beans after they’re roasted see “Postroast Flavors and Frills.”
Dedicated Home-Roasting Apparatuses
All currently available manufactured-from-scratch home coffee-roasting devices include a timer and controls that automatically trigger a cooling cycle, making all of these devices easier to use and less attention-demanding than improvised methods. They also efficiently remove chaff, the tiny, troublesome brown flakes liberated from coffee beans during roasting. These specialized home-roasting devices range in size and price from the little fluid- (or fluidized-) bed Fresh Roast, which currently sells for as little as $65 and roasts about three ounces of beans in a few minutes, to the gleaming and majestic Hottop Bean Roaster, which costs around $580 and roasts over a half-pound of coffee in fifteen minutes using classic drum-roaster technology.
Roasting with Dedicated Home Fluid-Bed Roasters
Fluid-bed roasting devices both agitate and roast beans with a powerful convection current of heated air.
ADVANTAGES
• Simpler and more automated than improvised roasting methods.
• Produce a consistent and uniform roast relatively quickly.
• Portable and easy to store, with small footprint.
• Cost considerably less than home drum roasters.
• Produce less smoke than home drum roasters.
DISADVANTAGES
• Roast considerably less coffee per session than home drum roasters and stove-top and oven methods.
• Currently available models are more expensive than ad hoc equipment used in improvised home-roasting methods, though cheaper by far than home drum roasters.
CURRENTLY AVAILABLE MODELS
• Original Fresh Roast: capacity per roast batch, 2.7 ounces (75 grams) by weight; costs around $65. Fresh Roast Plus: capacity per roast batch 3.5 ounces (100 grams) by weight, 5.5 ounces by volume; costs around $80.
• Hearthware Gourmet Coffee Roaster (also sold as Home Innovation Coffee Roaster): capacity per roast batch 3.5 ounces (100 grams) by weight, 5.5 ounces by volume; lists for $100 but often can be found for less.
• Brightway Caffé Rosto CR120: capacity 3.5 ounces (100 grams) by weight, 5.5 ounces by volume; lists for around $150 but often can be found for less.
The Hearthware Gourmet Coffee Roaster was one of the earliest of the current crop of home-roasting devices to come to market, and, at this writing, is still going strong on the basis of its simplicity and durability. The Hearthware Gourmet includes the standard set of features for such small fluid-bed machines. It roasts and agitates the beans by a current of hot air originating in the base of the machine, automatically initiates cooling based on the setting on the dial at the front of the unit, allows the user to observe the progress of the roast through a glass roasting chamber, and collects the chaff in a chamber that sits atop the machine.
POINTS OF COMPARISON AMONG COMPETING MODELS
• Original Fresh Roast is fastest roasting, with smallest bean capacity.
• Hearthware Gourmet and Brightway Caffé Rosto are slower roasting, with larger bean capacity.
• All three models offer visual access to roasting beans. Brightway Caffé Rosto allows best views of roasting beans, but pouring beans out of roaster is awkward.
• Hearthware Gourmet Coffee Roaster is rather noisy, making it virtually impossible to hear the “second crack,” an essential part of monitoring roast development by ear. Fresh Roast is quietest.
• Fresh Roast chaff collector is easiest to clean, Caffé Rosto chaff collector is hardest to clean.
• Fresh Roast roasting chamber sits rather precariously on roaster body and is easy to knock off and shatter.
• Hearthware Gourmet Coffee Roaster offers slightly more flexibility in terms of weight or volume of beans being roasted than does the Fresh Roast or Caffé Rosto. Bean movement in Fresh Roast or Caffé Rosto will stall if more beans than specified capacity are loaded. Fresh Roast is particularly sensitive in this regard.
TASTE NOTES
• In general, fluid-bed roasters emphasize bright, acidy notes in medium styles and pungency without charred notes in darker styles. Flavor profiles tend to be clean, sweet, and clearly articulated compared to the more complex and layered profiles of beans roasted in home drum roasters, gas ovens, and stove-top roasters and stove-top corn poppers.
• There may be subtle but substantial differences between coffees produced by fast-roasting fluid-bed machines like the original Fresh Roast (very bright, cleanly sweet) and those produced by slower-roasting units like Heartware Gourmet and the even slower Brightway Caffé Rosto (still cleanly articulated but somewhat lower-toned, rounder, fuller-bodied).
• Profiles can be altered slightly, brightening medium roasts and intensifying pungency in darker roasts by slightly (by 20 percent or so) decreasing volume or weight of beans being roasted.
WHAT YOU NEED
• Fluid-bed roasting device and accompanying instructions. See “Resources” for purchase information.
• Green coffee beans.
PROCEDURE
Fluid-bed devices may differ in details of operation. Follow the instructions that come with the device carefully. The following points may be helpful.
• Always start with the recommended weight or volume of green coffee beans. Too few beans may not roast properly, too many may not agitate sufficiently. Make sure beans begin to jostle and move at least slightly immediately after turning on device. If they do not begin moving until later in roasting cycle, reduce volume of beans for next round of roasting.
• Subtle adjustments in roast taste can be achieved by modestly reducing the volume of beans being roasted, particularly with Hearthware Gourmet and the Caffé Rosto. About 20 percent fewer beans will produce a faster roast and a brighter, more acidy/sweet profile in medium roasts and more pungency in darker roasts.
• If you seek precision in degree of roast, you may need to make adjustments on the fly, either advancing the dial to “cool” to stop the roast or by adding time to the roast cycle to extend it. See here for advice on controlling degree of roast using sound, smell, and bean color.
• Empty the chaff collector after every roast batch. To fail to do so will distort the performance of your roaster.
• Remove beans immediately after cooling cycle has been completed. Leaving beans in contact with a still-hot roasting chamber dulls flavor.
Roasting with Zach & Dani’s Gourmet Coffee Roaster
Zach & Dani’s Gourmet Coffee Roaster roasts coffee by means of a convection current of hot air but agitates the beans by means of a screw that rotates in the middle of the roasting chamber. Unique among home-roasting machines, it incorporates an electronic air cleaner that all but eliminates roasting smoke (though not roasting odor).
ADVANTAGES
• Roasts about 40 percent more coffee per batch at medium to moderately dark roasts than currently available devices using fluid-bed technology.
• Comes with a sophisticated air cleaner that substantially reduces the emission of roasting smoke.
• Controls are well designed, easy-to-use, and offer advantages both for those seeking walk-away automation and for those who want hands-on control.
• Costs considerably less than home drum roasters.
DISADVANTAGES
• Roasts considerably less coffee per session than home drum roasters and stove-top and oven methods.
• Requires much longer roast time than fluid-bed devices: 20 to 30 minutes.
• Has a somewhat larger footprint than fluid-bed roasters, though it is smaller and more portable by far than home drum roasters.
• Costs substantially more than ad hoc equipment used in improvised home-roasting methods and is somewhat more expensive than fluid-bed devices, though less expensive than home drum roasters.
CURRENTLY AVAILABLE MODEL
• Zach & Dani’s Gourmet Coffee Roaster: capacity per roast batch 5 ounces (140 grams) by weight, 7 ounces by volume for medium to medium-dark roasts; 3.5 ounces (100 grams) by weight, 5.5 ounces by volume for dark roasts; costs around $200 for a kit that includes a grinder, a supply of green beans, and instructional materials.
TASTE NOTES
• Relatively slow roast produces a low-toned, round, complexly layered cup, less acidy and sweet than a fluid-bed cup but heavier bodied.
WHAT YOU NEED
• Zach & Dani’s Gourmet Coffee Roaster and accompanying instructions. See “Resources” for purchase information.
• Green coffee beans.
PROCEDURE
Follow the instructions that come with the roaster carefully. The following points may be helpful.
• Although the Zach & Dani’s machine is more forgiving with regard to weight of roast batch than fluid-bed devices, it roasts best at no more than the recommended weight or volume of green coffee beans.
• Reducing the volume or weight of the beans being roasted by about an ounce, or about 20 percent, will produce a faster roast with a brighter, sweeter taste in medium roasts and will help achieve a faster, richer-tasting dark roast.
• If you seek precision in degree of roast, you may need to make adjustments while roast is taking place, either by pressing the COOL button to stop the roast or by adding time to the roast cycle by pushing the triangular UP button, 1 minute per push. See the instructions that accompany the roaster.
• Roaster noise makes it difficult to time the roast by ear, but the slow pace of roast and excellent visual access to beans makes it easier to monitor roast by time or bean color. See here for advice on controlling degree of roast by bean color.
• Empty the chaff collector after every roast batch.
• I recommend removing beans immediately after the cooling cycle has been completed. Leaving beans in contact with a still-hot roasting chamber dulls flavor. Either use oven mitts, or handle components by touching plastic and rubber surfaces only, avoiding contact with hot metal and glass elements.
Roasting with Home Drum Machines
These are miniature, simplified versions of the classic professional drum roaster.
ADVANTAGES
• Roast considerably more coffee per session than competing dedicated home-roasting devices.
• Project more authority and coffee romance than competing fluid-bed machines or improvised equipment.
• Hottop Bean Roaster efficiently cools beans outside the roasting chamber and is at this writing the only dedicated home-roasting device to do so.
• Exterior surfaces of Swissmar Alpenrost are safe to touch throughout roasting cycle, a unique advantage among currently available home-roasting devices.
DISADVANTAGES
• Both machines roast slowly compared to fluid-bed devices or hot-air corn poppers. Hottop requires an additional 5-minute warm-up before roasting and an approximate 10-minute cool-down before roasting a second batch.
• Although both machines incorporate smoke-control features (Alpenrost, an adjustable ventilation port that helps direct smoke toward an exhaust fan or window; Hottop, a fiber filter), both produce considerably more roast smoke than competing dedicated roasting devices simply because they roast more coffee per batch than such smaller-capacity units. Do not buy either of these drum roasting devices unless your kitchen is equipped with an efficient ventilating range hood or you plan to roast out-of-doors or directly in front of an open window.
• Require considerable counter space.
• Cost more than smaller, less romantic roasting devices with smaller batch capacity and much, much more than improvised equipment.
• Hottop is appropriately named; the external surfaces of the machine become very hot during roasting and stay that way for a long time thereafter. The manufacturer hopes to offer an insulated version of machine shortly.
• Roasting beans cannot be seen or monitored visually in Alpenrost, although Hottop provides excellent visual access.
Hottop home drum roasting machine. The Hottop felicitously combines traditional design (rotating drum, separate cooling outside the roasting chamber by means of fan and mechanical stirring) with features attractive to home users: excellent visual access to roasting beans through a glass panel at the front of the machine and a sophisticated computer chip that both automates the roasting procedure yet permits more experienced users some control over it.
AVAILABLE MODELS
• Swissmar Alpenrost: capacity per roast batch 8 ounces (225 grams) by weight; costs around $290.
• Hottop Bean Roaster: capacity per roast batch 9 ounces (250 grams) by weight; costs around $580.
POINTS OF COMPARISON BETWEEN COMPETING MODELS
• Hottop is more expensive than Alpenrost.
• Hottop offers visual access to roasting beans; Alpenrost does not.
• External surfaces of Hottop become very hot during and immediately after roasting; exterior of Alpenrost remains safe to touch throughout roasting cycle.
• Hottop cools beans quickly outside roasting chamber, a technical advantage. Alpenrost’s cooling is slow and rather inefficient, contributing to a low-toned cup profile with muted acidity and sweetness.
• Hottop is quieter, making it easier for those who roast by the sound of the crack to listen to the beans.
• Alpenrost’s straightforward controls make it easier to use for first-time roasters, whereas Hottop’s visual access to beans and more complex controls offer more information during the roast and more flexible control of degree of roast.
• Both are fine-looking appliances: Alpenrost is sleekly contemporary in appearance, Hottop romantically traditional.
TASTE NOTES
• Swissmar Alpenrost: low-toned, full-bodied, with muted acidity and sweetness.
• Hottop Bean Roaster: brighter, higher-toned, lighter-bodied, more pronounced acidity and sweetness, and a generally more classic cup than that produced by the Alpenrost but slightly rounder and fuller cup than produced by fluid-bed roasters.
WHAT YOU NEED
• Home drum roasting device and accompanying instructions. See “Resources” for purchase information.
• Green coffee beans.
PROCEDURE
Follow the instructions that come with the roaster carefully. The following points may be helpful.
• Don’t overload either device with green beans, although Hottop is a bit more forgiving in this respect than Alpenrost. It is possible to alter the roast profile by modestly decreasing the charge of green beans: About 20 percent fewer beans will produce a faster roast with a sweeter, more acidy profile in medium roasts and a more pungent character in darker roasts.
• Alpenrost does not permit monitoring of roast by observing changing color of beans. If you wish to roast by sound and smell (See here) with Alpenrost, start with a high or “dark” setting and stop roasting at desired juncture by pressing COOL button, because controls do not permit adding time during roast cycle. For more information on this procedure see Swissmar Alpenrost Experienced Roasters Guide at www.swissmar.com/exproast.shtmil.
• Hottop permits both stopping roast at will or lengthening roast by adding time in 10-second increments. Alarm sounds well before roast is about to conclude, allowing sufficient time to make such adjustments. Read the well-detailed instructions that accompany the roaster.
• Always empty chaff collectors and clean roasters regularly as indicated in the instructions.
• Be careful not to touch the Hottop during or after operation; all exterior surfaces become extremely hot.
Roasting with “Wave-Roast” Microwave Packets and Cones
Be advised that the microwave packets currently distributed by an organization called Smiles Coffee do not result in home-roasted coffee. The beans in the microwave pouches are already roasted when sold. All you do is heat them up. Perhaps there is some merit to the Smiles product, but I can’t find it. Do not confuse Smiles Coffee with the genuine microwave-roasted coffee products described below.
At this writing an ingenious microwave coffee-roasting system tentatively called Wave Roast is on its way to market. The system is comprised of two products, one simpler and less expensive and the other more sophisticated and a bit more expensive.
The simpler product will consist of microwave packets, each filled with two ounces of green coffee, a cardboard stand to prop up the packets inside the oven, and a water reservoir. The water reduces energy in the microwave chamber to an appropriate level for coffee roasting and helps clean the air inside the microwave by absorbing roasting smoke. After the first popping sound indicates that roasting has begun, the user periodically stops the oven, reaches inside, and inverts the packet to help roast the beans evenly. The color of the roasting beans can be observed through a little transparent window. The entire procedure takes about four minutes.
The more sophisticated system seals the beans inside cardboard cones. The cones also will come preloaded with approximately two ounces of green coffee, which roasts in about four minutes. But, in the case of the cones, beans are agitated during roasting by a rolling motion imparted to the cone by an attractive, rechargeable battery-operated “roller” that sits atop and supplements the turning motion of the microwave turntable or by a small microwave oven specifically modified to roast coffee with the Wave-Roast cones. In both cases, an electronic sensor will monitor the roasting beans and signal when the desired roast level has been reached.
Tentative design of Wave Roast microwave roasting cone and roller. The disposable cone is constructed of recyclable cardboard and is preloaded with green beans. A patented lining converts some microwave energy to radiant energy, which roasts the outsides of the beans while microwaves roast the insides. The cone sits atop a rechargeable battery-driven device that imparts a rolling motion to the cone, agitating the beans inside to assure even roasting.
Neither packets nor cones are designed to be refilled. The manufacturer hopes to offer the packets at about $1 each. The cones probably will be sold in a starter kit, including seven cones charged with green beans, roller, and blade-type coffee grinder for around $40. Purchased singly, preloaded cones will sell for $1.75 to $3.50, depending on coffee origin.
ADVANTAGES
• Cones are very easy to use. (Packets are not.)
• Packets require no counter space, roller for cones requires very little.
• Little to no investment in specialized equipment is required.
• Virtually smokeless until a packet or cone is opened after roasting, at which point only a small puff of smoke is released.
DISADVANTAGES
• Roast relatively small volume of coffee per batch.
• Packets roast beans unevenly. (Cones roast relatively evenly.)
• On an ongoing basis, packets are expensive because of added cost of recyclable (but not reusable) cardboard packets and cones.
• Packets are awkward to use and require almost continuous observation during roasting. (Cones are easy to use.)
• Probably the least traditional and romantic of roasting methods.
TASTE NOTES
• Packets: uneven roast brings out complexity and depth of taste, since a range of roast styles may be present simultaneously in any given sample of beans. Acidity and sweetness are muted, body deepened. Produces the best results for those who like medium-dark (full-city) through moderately dark (espresso) styles. Should be avoided by those who prefer either very light or very dark roasts.
• Cones: At medium through medium-dark roast styles, produce a full-bodied cup with muted acidity and sweetness. They are at their best with darker roast styles, which remain roasty tasting but sweet and virtually completely free of charred and bitter tones.
• Taste notes are based on pre-product-release versions of the cones. Later alterations in cone design or microwave instructions may result in different cup profiles.
Stove-Top Roasting with the Aroma Pot Stove-Top Coffee Roaster
This contemporary variation on the traditional stove-top coffee roaster popular in nineteenth-century America and Europe can be purchased as part of a roasting kit on the Internet (see “Resources”). It looks like a small covered saucepan with a crank protruding from the top and must be used on a gas or electric burner or range top. The crank turns a pair of metal paddles that agitate the beans inside the pot during the roast.
ADVANTAGES
• More beans can be roasted per batch than with fluid-bed methods.
• Portable and easy to store.
• Coffee romantics may find the traditional design appealing.
• Has no motor or controls that can malfunction or wear out.
DISADVANTAGES
• Beans are roasted much less uniformly than with fluid-bed and drum devices.
• Beans cannot be observed easily during roasting.
• Roast temperature cannot be controlled with precision.
• Process requires continuous cranking during roast session plus occasional shakes, as well as a separate procedure for cooling beans.
• If vanes that agitate coffee jam or bend, there is no way of accessing interior of roaster to bend them back into place.
• Produces considerable roasting smoke and should only be used under an efficient kitchen exhaust fan or next to an open window.
CURRENTLY AVAILABLE MODEL
• Aroma Pot ½-Pound Coffee Roaster. Currently sold by The Coffee Project (See here) as part of a kit that includes the Aroma Pot itself, equipment for cooling coffee, storage canisters, and substantial quantities of green coffee, and costs around $140.
TASTE NOTES
• Performed carefully, roasting with the Aroma Pot produces a low-toned, full-bodied cup with muted acidity and sweetness and complexity in the lower range of the profile.
WHAT YOU NEED
• Aroma Pot ½-Pound Coffee Roaster (sold with colanders and spray bottle for cooling beans). See “Resources” for purchase information.
• Green coffee beans.
• Optional: Sample beans roasted to degree or darkness of roast you prefer.
PROCEDURE
Follow the instructions that come with roaster. The following points may be helpful.
• Start with a medium heat setting. If pyrolysis, signaled by a popping sound of the “first crack,” occurs in less than 3 minutes, decrease heat and plan to do likewise with next roast batch. If more than 5 minutes elapses before the first crack, increase heat slightly and plan to do likewise with next roast batch. After determining a heat setting that produces a first crack between 3 and 5 minutes, mark setting for future reference. Very hot ambient temperatures may accelerate roast times, in which case reduce heat slightly when such conditions occur.
• You don’t need to turn the crank rapidly, and you can step away for a moment, but you must persist. Abandoning cranking for more than a minute will certainly cause bottom layer of beans to scorch. Important: Occasionally lift the roaster and shake it to further agitate the beans.
• Always dump beans from Aroma Pot into a colander for cooling immediately after removing the device from the heat. If you leave them inside the hot roaster you will seriously dull the flavor.
Stove-Top Roasting with a Crank-Type Corn Popper
ADVANTAGES
• Beans are accessible and can be studied easily as roast progresses.
• Beans roast somewhat more uniformly than with oven method or Aroma Pot.
• Portable and easy to store.
• More beans can be roasted per session than with fluid-bed devices.
• Costs considerably less than any manufactured-from-scratch roasting device.
DISADVANTAGES
• Beans are roasted less uniformly than with fluidized-bed or drum devices.
• Process requires continuous cranking and attention during roast session.
• Corn popper requires simple modification before it can be used for coffee roasting.
• Produces considerable roasting smoke and should only be used under an efficient kitchen exhaust fan or next to an open window.
TASTE NOTES
• Performed carefully, roasting with the Whirley Pop produces a low-toned, full-bodied cup with muted acidity and sweetness and complexity in the lower range of the profile.
Correct installation of candy/deep-fry thermometer in the Whirley Pop stove-top corn popper. The thermometer enables the home roaster to monitor temperature inside the popper before and during the roast. See here for an overview illustration of the popper with thermometer installed. (A) Thermometer dial. (B) Nuts and/or washers sufficient to raise the tip of the thermometer about 5⁄8 to ¾ inches above the inside bottom surface of popper. (C) Thermometer clip flush to the bottom surface of popper lid to secure the thermometer in place. (D) Tip of thermometer raised just high enough to clear stirring rods and roasting beans.
WHAT YOU NEED
For roasting sessions:
• Whirley Pop stove-top corn popper (6-quart model) modified to accommodate candy thermometer as described below. At this writing popper is available for purchase already modified with a thermometer. See “Resources.”
• Green coffee beans (approximately 9 ounces by weight or 12 fluid ounces per session for Whirley Pop 6-quart model).
• Colander for cooling that is large enough to accommodate about twice the volume of green beans you intend to roast.
• Kitchen exhaust fan or open window to dissipate roasting smoke.
• Oven mitt.
• Optional: Sample beans roasted to degree or darkness of roast you prefer.
For modifications to popper:
• Candy/deep-fry thermometer with dial and metal shaft that measures temperatures to 400°F/205°C or higher. Cooper, Springfield, UEI model T550, Comark, Pelouze, or Taylor brands all work well. See “Resources.”
• Metal nuts or washers with holes large enough to slide onto shaft of thermometer and with sufficient total thickness to occupy about ½ to 1 inch of shaft length. (Not needed with UEI, Pelouze, or Comark 550F models or other thermometers with shaft of 5 or fewer inches long).
• ¼-inch high-speed drill bit and drill.
PROCEDURE
Modification to Whirley Pop corn popper (see illustrations on this page and here).
• Drill ¼ inch hole through popper lid. Lid has two hinged halves. Drill hole through center of half-lid that has clamp closure. Carefully remove and dispose of all aluminum shavings.
• Remove clip from thermometer. String sufficient metal nuts and/or washers on upper part of thermometer shaft to raise tip of thermometer about 5⁄8 to ¾ inch above bottom surface of popper. (See illustration).
• Insert thermometer in popper, with nuts and washers positioned between bottom of dial and upper surface of lid.
• Reach inside popper and slip clip back onto shaft of thermometer. Slide clip up to underside of lid to secure thermometer in place.
• (UEI/Pelouze/Comark 550F model has short shaft, so it requires no nuts or washers. It lacks clip and simply rests loosely in hole. It may rattle around but will be perfectly functional.)
ROASTING PROCEDURE
• Never use high heat under popper. On electric stoves start with a larger burner set to medium, on gas stoves start with a low flame.
• Never use popper without thermometer installed.
• Never abandon popper over heat.
• Make certain that cooling colander and oven mitt are at hand. If you wish to accelerate cooling of beans by water quenching (See here), have a pump-spray bottle ready.
• Preheat popper by placing it over a medium heat setting (electric range) or low flame (gas range). Stand by and observe thermometer dial. The temperature will climb fairly rapidly. When indicator passes 400°F carefully modulate heat setting until temperature steadies at approximately 475°F to 500°F. (The candy thermometer may be calibrated only to 400°F. If so, the thermometer still can be used to accurately approximate higher readings. For example, 500°F is achieved when pointer circles past 400°F and returns to 100°F; 450°F is halfway between the two; and so on). Make note of burner setting. If you have a gas range, indicate approximate setting with a marking pen or bit of tape. Use this setting for future roasting sessions.
• Place green coffee beans in popper; close lid.
• Begin cranking handle of popper. You don’t need to crank rapidly, and you can step away for a moment, but you must persist. Abandoning cranking for more than a minute will certainly cause bottom layer of beans to scorch. Occasionally beans may catch between stirring rod and bottom of popper causing crank to resist turning. If so, simply reverse direction of cranking. If crank still resists, see “Problems and Refinements” for this section.
• After beans are in popper, the temperature as indicated by the thermometer will gradually decrease. If temperature declines below 325°F turn up heat slightly.
• During remainder of session the thermometer will register slowly recovering temperatures, typically stabilizing at 350°F to 375°F. (Actual roasting temperatures on bottom of popper are higher.)
• About 1 minute after smoke and crackling begin (for lighter roasts) to 2 minutes (for darker roasts) check beans by lifting free half of popper cover. If you are deciding when to end the roast by bean color as well as by sound and smell (See here), compare color of roasting beans with that of sample beans.
• Monitor roast at frequent intervals by sound or until beans reach same or slightly lighter color than your sample. When target is reached, immediately turn off heat and dump roasted beans into colander.
• Over sink or out-of-doors, stir or toss beans in colander until they are cool enough to touch and until most loose roasting chaff has floated free. To accelerate cooling, water-quench as described here. For more on chaff removal, See here.
PROBLEMS AND REFINEMENTS
If crank resists turning, heat may be causing bottom of popper to expand upward, interfering with movement of shaft that turns wire stirring vanes. Simply wait until popper is cool and place tip of kitchen spoon or similar long, blunt tool against bottom of popper next to shaft and press down firmly. Repeat on opposite side of shaft. Bottom of popper will depress slightly and (usually) permanently, freeing shaft to turn without interference. If your efforts produce slight indentations in bottom of popper don’t be concerned; the operation still will be a success.
Roasting with Recommended Designs of Hot-Air Corn Popper
ADVANTAGES
• Somewhat simpler than other improvised methods, though it involves more effort and attention than that required by dedicated, manufactured-from-scratch home-roasting equipment.
• Produces more consistent and uniform roast than other improvised methods.
• Can accommodate installation of a thermometer for reliable monitoring of degree or color of roast.
• Portable and easy to store.
• Costs considerably less than manufactured-from-scratch roasting devices.
DISADVANTAGES
• Requires considerably more attention during and after roasting than that required by manufactured-from-scratch roasting devices.
• Only those units with the recommended popping chamber design (see illustration here) should be used to roast coffee. Other designs are potentially dangerous when employed for that purpose.
Interiors of popping chambers in three typical hot-air corn poppers. Use only designs like the one on the right for coffee roasting, in which hot air issues into the chamber from diagonal slots in the chamber wall. Do not use designs like those pictured in center and on left, in which hot air issues into the popping chamber from the bottom of the chamber.
• Roasts considerably less coffee per session than home drum roasters and stove-top and oven methods.
• Regular use to achieve very dark roasts (dark brown and shiny with oil, common names Italian or dark French) will shorten life of popper. However, hot-air poppers can be used to produce moderately dark roasts of the kind usually called Viennese or espresso. See the “Quick Reference Guide to Roast Styles,” here.
TASTE NOTES
• Hot-air poppers emphasize sweet, acidy notes in medium styles and pungency without charred notes in darker styles. Flavor profiles tend to be clean, sweet, and clearly articulated compared to the more complex and layered profiles of beans roasted in home drum roasters, gas ovens, and stove-top roasters and corn poppers.
WHAT YOU NEED
• Hot-air popper of recommended design only (see illustration here). Other designs may be dangerous when used to roast coffee.
• Large bowl to collect chaff.
• Green coffee beans (same volume per batch as that of popping corn recommended by manufacturer of popper, usually about 4 fluid ounces or ½ cup).
• Colander for cooling that is large enough to accommodate about twice the volume of green beans you intend to roast.
• Two oven mitts or pot holders.
• Optional: Sample beans roasted to degree or darkness of roast you prefer.
A hot-air corn popper with bowl positioned to catch roasting chaff as it drifts out of the popper.
PROCEDURE
• Position popper under kitchen exhaust fan or near open window to dissipate roasting smoke. Can be positioned out-of-doors, but only in clement weather; low ambient temperatures (under 50°F/10°C) may prevent coffee from roasting properly.
• Place in popping chamber same volume of green beans as volume of popping corn recommended in instructions accompanying popper. Do not exceed this volume.
• Make certain plastic chute (hoodlike component above popping chamber) is in place. Do not operate without chute; it assists in maintaining the proper temperature in popping/roasting chamber.
• Place large bowl under chute opening to catch chaff (see illustration here).
• Place sample roasted beans where they can be easily seen for color comparison with beans inside popper. Make certain cooling colander and oven mitts are at hand. If you wish to accelerate cooling of beans by water quenching (See here), have a pump-spray bottle ready.
• Plug in or turn on popper.
• In approximately 3 to 4 minutes coffee-smelling smoke will appear and beans will begin to crackle. Turn on a kitchen exhaust fan if indoors.
• About 1 minute after smoke and crackling begin (for light to medium roasts) to 2 minutes (for moderately dark roasts) begin checking color of beans by lifting out butter cup with oven mitt and peeking into popping chamber. If popper design does not incorporate a butter cup, either check color by lifting off entire hood, or monitor roast by listening to the crack, a reliable method of control described here.
• Roast develops relatively quickly with hot-air poppers, typically 5 to 6 minutes to medium roast, 7 to 8 minutes to medium-dark, 9 to dark.
• Monitor roast continuously by sound or until beans reach same or slightly lighter color than your sample. When desired degree of roast is achieved, unplug or turn off popper and, using oven mitts, immediately lift popper and pour beans out of popping chamber through chute opening into cooling colander.
• Place colander under kitchen exhaust fan and stir or toss beans until warm to touch. To accelerate cooling, water quench as described here.
Hot-air popper with candy/deep-fry thermometer installed. The thermometer measures the approximate internal heat of the roasting beans, permitting monitoring of the progress of the roast by temperature.
PROBLEMS AND REFINEMENTS
Hot-air poppers can be easily fitted with metal candy thermometers to monitor the approximate inner temperature of the roasting beans. Since the internal temperature of the beans correlates to the degree or style of roast, this modification permits the emulation of the procedure of technically inclined professionals who use the approximate internal temperature of beans to determine when to conclude the roasting session.
This modification differs in purpose from the somewhat similar procedure suggested for the Whirley Pop stove-top popper discussed earlier in this section. Here the goal is to monitor the temperature of the roasting beans, not the air temperature.
What you need for modification (see illustrations here)
• Candy/deep-fry thermometer with dial and metal shaft that measures temperatures to 400°F or 500°F or 550°F. Shaft must be long enough to project from bottom of plastic butter cup or hood to a point about 2 to 3 inches above bottom of popping/roasting chamber. The Cooper brand thermometer fits most poppers perfectly. The Taylor brand has a shaft about ½ inch longer than the Cooper’s; Insta-Read is longer still. The shaft of the UEI/Pelouze/Comark 550F thermometer is 5 inches long, too short for some popper models. (Measure before you buy!) See “Resources” for thermometer availability.
• ¼-inch high-speed drill bit and drill.
• If necessary: metal nuts or washers with holes large enough to slide onto shaft of thermometer. These may be required as spacers between underside of thermometer dial and top surface of butter cup or hood to raise tip of thermometer shaft to recommended minimum 2 inches from bottom of popping/roasting chamber.
Modification procedure (see illustrations here).
• Drill ¼-inch hole through center of plastic butter cup or top of popper hood. Carefully remove and dispose of all plastic shavings.
• Remove clip from thermometer. If necessary, string sufficient metal nuts and/or washers on upper part of thermometer shaft to raise tip of thermometer a minimum of approximately 2 inches above bottom of popping/roasting chamber.
Installation of a candy/deep-fry thermometer in the recommended designs of hot-air popper. Use recommended design poppers only (See here). The thermometer permits monitoring the approximate internal temperature of the beans as they roast. (A) Thermometer dial. (B) Thermometer clip flush to the bottom surface of the butter cup to secure the thermometer in place. (C) Thermometer tip protruding to within 1 to 3 inches of the bottom surface of popping/roasting chamber. The green beans may not touch the thermometer tip at the start of roasting but will expand and surround it as roasting proceeds. (If the thermometer tip extends to closer than 1 inch from the bottom of the popping chamber, insert sufficient nuts or washers between the underside of the thermometer dial and the surface of the butter cup to raise the tip to a minimum 1 inch above the bottom.)
• Insert thermometer in popper with nuts and washers (if necessary) positioned between underside of dial and upper surface of butter cup or hood.
• Slip clip back onto shaft of thermometer. Slide clip up to underside of butter cup or hood to secure thermometer in place.
Monitoring the progress of the roast with the installed thermometer:
• Consult the “Quick Reference Guide to Roast Styles” for equivalents of bean temperature and roast style.
• When temperature on thermometer approximately matches temperature for your preferred roast style, unplug or turn off popper and, using oven mitts, immediately remove plastic chute and thermometer from top of popper, lift popper, and pour roasted beans into cooling colander.
• Your candy thermometer may be calibrated only to 400°F. If so, the thermometer still can be used to accurately approximate higher temperature readings. For example, 450°F is achieved when pointer has circled the dial and centers between 400°F and 100°F.
• With hot-air poppers do not attempt to achieve roasts with final internal temperatures higher than about 460°F/240°C (moderately dark to dark brown color; common names Viennese or espresso).
Roasting in a Gas Oven
ADVANTAGES
• Temperature in roasting chamber (i.e., oven) is easily controlled and roughly repeatable.
• With most gas ovens, roasting smoke is effectively vented.
• More coffee can be roasted in a given session than with most other methods.
• Control over temperature enables those who roast systematically to compensate roughly for differences in density of green beans and broadly influence the taste of the roast.
DISADVANTAGES
• Hot spots inside some ovens and lack of strong convection currents may cause beans to roast unevenly: some beans lighter, some darker, some between. Solutions to this problem may require patience and experiment.
• Timing roast can be difficult because color of beans may not be uniform, and beans may be difficult to see and the sounds they produce difficult to hear inside oven.
• Precision in roast style may be difficult to attain owing to uneven roasting.
TASTE NOTES
• A somewhat uneven roast brings out complexity and depth of taste, since a range of roast styles may be present simultaneously in any given sample of beans. Acidity and sweetness may be muted, body deepened. Gas-oven roasting probably produces the best results for those who like medium-dark (full-city) through moderately dark (espresso) styles. It probably should be avoided by those who prefer either very light or very dark roasts.
WHAT YOU NEED
• Ordinary kitchen gas oven. (Do not attempt to use an electric range or a toaster or microwave oven for coffee roasting. Conventional electric kitchen ovens can be used following these instructions but typically produce roasts too uneven for most tastes. For electric convection ovens consult the section here).
• One or more flat, perforated pans with raised edges. Perforated baking pans designed to crisp bottom crusts of breads or pizzas work well. Perforated vegetable steamers with folding, petallike edges also work, though they are much less handy than perforated baking pans. Perforations should be relatively close together (no more than 1⁄8 inch apart) and small enough to prevent coffee beans from falling through (maximum about 3⁄16-inch diameter). Pan should have raised lip around edges. See examples of such pans below and here and suggestions for obtaining them in “Resources.” In larger ovens more than one baking pan can be used per roasting session.
• Enough green beans to densely and uniformly cover surface of baking pan(s) one bean deep.
A typical perforated pan for gas-oven and convection-oven roasting.
• Colander for cooling that is large enough to accommodate about twice the volume of green beans you intend to roast.
• Two oven mitts or pot holders.
• Flashlight (necessary only if interior of oven is not illuminated and remains dark when you peer through window or crack open door).
• Optional: Sample beans roasted to degree or darkness of roast you prefer.
PROCEDURE
• Note: Virtually all gas ovens will produce a reasonably consistent and very flavorful roast, but success may require patience and experimentation. If your first roast emerges uneven in color, don’t give up. Consult “Problems and Refinements” for this section.
• Preheat oven to 500°F/260°C to 540°F/280°C, depending on condition of green coffee and desired taste characteristics. For fresh, new-crop coffees, set to 540°F/280°C; for past-crop, aged, or monsooned beans, set to 520°F/270°C; for decaffeinated beans, set to 500°F/260°C. For a brighter, more acidy taste in medium roasts and more pungency in dark roasts try upper range of temperature, for more body and less acidity/pungency use lower end of range. If beans take longer than 15 minutes to reach a medium roast or 20 minutes to reach a moderately dark to dark (espresso) roast, or if they taste bland or flat, start with a higher temperature on subsequent sessions.
Patting the surface of the green beans with an open hand is a good way to make certain the beans are distributed evenly, one deep, across the entire surface of the perforated pan used for oven roasting.
• Spread green beans closely together, one bean deep (no deeper) across entire perforated surface of baking pan. Pat beans down with a flattened hand until they are densely but evenly distributed, touching or almost touching, but not piled atop one another. Make certain entire surface of pan is covered with a single layer of beans. See illustration here.
• Place baking pan charged with beans on middle shelf of preheated oven.
• If you intend to control degree of roast by color of beans, place sample roasted beans where they can be easily seen for color comparison with beans inside oven. Make certain cooling colander and oven mitts are at hand. If you wish to accelerate cooling of beans by water quenching (See here) have a pump-spray bottle ready.
• In about 7 to 10 minutes you should hear crackling from inside oven and smell coffeelike scent of roasting smoke.
• About 2 minutes after crackling begins (for lighter roasts) to 3 minutes after crackling begins (for darker roasts) peek inside oven, with a flashlight if necessary. If oven has no window, crack open oven door only for as long as it takes to compare color of beans inside oven with that of the sample of roasted beans.
• Continue peeking at about 1-minute intervals, comparing roasting beans to sample beans. When average color of roasting beans is satisfactory or approximately same as that of sample, pull baking pans out of oven using oven mitts and dump beans into colander.
Details of two perforated baking pans or sheets appropriate for roasting coffee in a gas or convection oven. The important features for any oven coffee-roasting pan are holes sufficiently close together to permit circulation of hot air and small enough to prevent the beans from falling through or catching, and a raised lip around the edge of the pan.
• Over sink or out-of-doors, stir or toss beans in colander until they are cool enough to touch and until most of loose roasting chaff has floated free. To accelerate cooling, water quench as described here. For more on chaff removal, See here.
PROBLEMS AND REFINEMENTS
Actual temperatures in ovens may differ from control settings. Consider comparing the actual temperature as indicated by an oven thermometer to the temperature setting on oven before your first roasting session. Compensate for any difference when setting temperatures thereafter.
Beans always will roast somewhat unevenly. Nevertheless, they may taste as good as or better than uniformly roasted beans. Try them. If you don’t like the flavor complexity, or if the range between dark and light beans is too great (if darkest beans are almost black and lightest beans medium-brown, for example), one or more of the following adjustments may be needed.
• Make certain beans are tightly and uniformly spread one bean deep but no more over entire surface of pan.
• Use middle oven shelf. If results on middle shelf are unsatisfactory, experiment with higher or lower placement.
• Place one or more cookie sheets on lower shelf of oven to break up flow of hot air through oven and thus dissipate “hot spots.” Arrange pans charged with coffee beans on upper shelf above cookie sheets. Position cookie sheets in relation to bean-charged pans so as to break up pattern of hot spots revealed by previous roast sessions. In other words, if beans in middle of roasting pan emerge darker than beans at sides, position a cookie sheet directly below roasting pan. If darker beans are at back of pan, position a cookie sheet somewhat farther back in oven than roasting pan, etc.
• If cookie-sheet strategy is successful (it usually is), beans may take longer to reach pyrolysis. If beans take longer than 15 minutes to reach a medium roast or 20 minutes to reach a moderately dark (espresso) roast, or if they taste bland or flat, start with a higher temperature on subsequent sessions.
• If you are using more than one shelf in oven and beans roast unevenly from shelf to shelf, arrange pans on one shelf only (middle shelf is usually best).
• If cookie-sheet strategy fails and beans still roast unevenly across surface of pan, rotate pan about a half turn approximately every 3 minutes during roasting. This is a last resort and seldom required.
Oven roasting offers the potential for control over temperature and timing. Keep records of oven settings and elapsed time of roasts while roasting the same amount of similar green beans. When you achieve a roast you enjoy use the same oven setting and set a kitchen timer for 2 minutes or so before the termination of the roast, thus minimizing time spent peeking into oven to check roast color. You still must make a final decision when to stop the roast based on visual observation of the bean color, since differences in atmospheric pressure and ambient temperature alter the length of a roast from session to session. See here for more advanced experiments with record keeping.
Roasting in a Convection Oven
Note: Only convection ovens with maximum settings of 450°F/230°C or higher can be used to roast coffee. Test the oven for actual heat output. Preheat the oven to a maximum temperature setting (usually 450°F/230°C to 500°F/260°C) with an oven thermometer positioned inside. If the actual temperature inside the oven as registered by the thermometer peaks at 475°F/245°C to 500°F/260°C the oven will produce an acceptable to excellent roast. If the actual temperature is 450°F/230°C to 460°F/240°C try a roast, but most likely the beans will not expand and the coffee will taste flat. If the temperature registers below 450°F/230°C do not attempt to use the oven for coffee roasting.
ADVANTAGES
• Temperature in roasting chamber (i.e., oven) is easily controlled and repeatable.
• More coffee can be roasted in a given session than with most other methods.
• Produces a relatively consistent and uniform roast.
• Most convection ovens permit easy visual inspection of roasting beans, making monitoring roast color easier than with many other methods.
DISADVANTAGES
• Maximum temperature in most convection ovens (see note at head of this section) is barely high enough to induce a proper roast.
• Monitoring of roast must be done mainly on the basis of bean color, since the cycle of the crackling beans typically cannot be heard above the sound of the oven fan.
TASTE NOTES
Important: Most convection ovens, owing to low heat output relative to roasting requirements, produce a mild, sweet roast with muted acidity and relatively weak aroma.
WHAT YOU NEED
• Convection oven with maximum temperature of at least 450°F/230°C, preferably 500°F/260°C. (See note at head of this section. Do not purchase a convection oven for coffee roasting unless it incorporates a maximum temperature setting of at least 500°F/260°C and permits easy visual inspection of roasting beans through clear, nontinted glass.)
• Perforated baking or pizza pan of kind recommended for gas-oven roasting (See here).
• Sample beans roasted to your preferred style.
• Enough green beans to densely cover entire surface of baking pan(s) in a single layer.
• Colander for cooling that is large enough to accommodate about twice the volume of green beans you intend to roast.
• Two oven mitts or pot holders.
• Optional: Sample beans roasted to the degree or darkness of roast you prefer.
PROCEDURE
• Make certain a raised rack or shelf is in place in oven. Do not place perforated baking pan directly on a carousel or floor of oven; use raised rack or shelf. Do not use microwave or mixed microwave/convection function in ovens that offer both convection and microwave options.
• Preheat oven to highest available temperature setting but no higher than 530°F/270°C. If oven offers more than one air velocity setting, experiment. Use highest velocity that does not blow chaff out of beans, usually low. Until you have established a roasting routine through experimentation with your particular oven, set timing function for 25 minutes. Coffee will roast in approximately 12 to 25 minutes, depending on heat-transfer rate of oven and desired degree of roast.
• Spread green beans closely together, one bean deep (no deeper) across entire perforated surface of baking pan. Pour beans onto pan, then pat them down with a flattened hand until they are densely but evenly distributed.
• Place baking pan charged with beans in preheated oven.
• Place sample roasted beans where they can be easily seen for color comparison with beans inside oven. Make certain cooling colander and oven mitts are at hand. If you wish to accelerate cooling of beans by water quenching (See here), have a pump-spray bottle ready.
• In about 10 to 15 minutes you should begin to smell coffeelike scent of roasting smoke. If oven is built-in and vents efficiently you may not smell smoke and will need to make frequent visual checks of color of roasting beans through oven window until you have established your own timing routine for roasting.
• After appearance of roasting smoke observe beans through oven window at 1- to 2-minute intervals, comparing them to sample beans if you wish. When average color of roasting beans is satisfactory, or approximately same as that of sample, stop oven, pull baking pan out of oven using oven mitts, and dump beans into colander.
• Over sink or out-of-doors, stir or toss beans in colander until they are cool enough to touch and until most loose roasting chaff has floated free. To accelerate cooling, water quench as described here. For more on chaff removal, See here.
PROBLEMS AND REFINEMENTS
If you roast the same amount of green beans per session and record the elapsed time of each session you can begin to predict the approximate time your oven requires to achieve a given roast style. Then set a kitchen timer for approximately 2 minutes before you anticipate concluding the roast. You still must make a final decision when to stop the roast based on visual observation of bean color, since differences in atmospheric pressure and ambient temperature alter the length of a roast from session to session.
A few convection ovens may roast unevenly (beans at front or back of pan may roast more darkly than beans at opposite end, for example). Roasts that are only mildly inconsistent may taste as good or better than more consistent roasts. But if lack of uniformity is extreme or bothers taste, try repositioning the roasting pan in a different part of the oven, usually toward front or back. If that doesn’t work, open the oven every 3 to 4 minutes and, using oven mitt, rotate the pan a quarter or half turn. This strategy is a last resort and is usually not necessary.
Ovens Combining Conventional and Convection Functions
Some contemporary electric ovens permit cooks to chose options ranging from conventional thermal operation through pure convection to combinations of the two. With such ovens try the combined convection-thermal setting.
Preheat the oven to 425°F to 450°F/220°C to 230°C. For brighter, more acidy taste in medium roasts and more pungency in dark roasts try upper range of temperature, for more body and less acidity/pungency use lower end of range. Follow the instructions given earlier in “Roasting in a Gas Oven.”
Getting the Roast Color You Want
Look at the chart here to help determine your preferences in terms of “color” or degree of roast. Because the longer beans roast, the darker their color, beginning roasters often focus too rigidly on elapsed time as a way of controlling the roast. Remember that the time it takes to achieve a given degree of roast is relative and determined by many variables including the density and moisture of green beans, the ambient temperature of the room in which you are roasting, and, if relevant, fluctuations in the electrical current. You may need to make adjustments during roasting, either stopping the roast by intervening to initiate the cooling cycle or adding time to the roast cycle, in order to achieve a precise degree of roast.
To understand how to read the roast by eye, ear, and nose, read here. Learning to listen to the roast is particularly helpful. To summarize: For sweet, briskly acidy medium roasts, stop the roast after the first loud popping ends but before the quieter, crinkling-paper sound of the second crack begins. For round, sweet roasts stop the roast just as the crinkling sound of the second crack starts. For darker espresso-style roasts wait until the crinkling sound of the second crack is just beginning to rise toward a continuous crescendo and the beans begin producing dark, intense-smelling roasting smoke. Wait only briefly beyond this moment for extremely dark “French” roasts. Things happen very quickly once the second crack begins. Don’t wait too long into the crescendo of the second crack or you will outright burn the beans.
Cooling Beans After Roasting
Precise, rapid cooling of freshly roasted beans is essential to good flavor. Ideally, beans should be warm to the touch within 2 to 3 minutes after the conclusion of the roast.
Dedicated, made-from-scratch home-roasting devices all incorporate a built-in cooling cycle. Typically, the heating element kicks off while a fan continues to circulate room-temperature air through the hot beans, which remain in the same chamber in which they were roasted. Cooling beans inside the roasting chamber produces a good cup in home devices because the volume of beans being roasted is small. Larger-batch professional roasting machines must cool the coffee outside the hot roasting chamber to avoid completely destroying the flavor by slow, sluggish cooling.
Among currently available dedicated home-roasting devices only the Hottop drum roaster (here) dumps the beans into a separate cooling tray outside the roasting chamber, where they are cooled by a current of room-temperature air supplemented by mechanical stirring.
Kicking off the cooling process for just-roasted beans with a few one-second bursts of purified water, applied with a very fine spray. Done correctly, such water quenching will improve the quality of the roast by decisively initiating cooling. Done incorrectly, it can harm the roast by promoting staling.
With improvised home-roasting methods the beans must be cooled manually by immediately removing them from the roasting chamber and stirring or tossing them in a colander. The cooling process can be accelerated by subjecting the beans to a light, brief spray of purified water (water quenching) immediately after removing them from the roast chamber or by placing the beans in a freezer compartment until they reach room temperature.
Never allow hot beans to sit untouched in a receptacle and cool of their own accord. They will lose considerable aroma and liveliness.
Cooling beans by stirring or tossing them in a colander should be performed over a sink or out-of-doors, since roasting chaff will be released in the process.
I strongly recommend careful, restrained water quenching for cooling all coffee roasted by improvised methods, although for small batches (4 to 6 ounces by weight or volume) simply stirring or tossing the hot beans in a colander can be sufficient. If you roast ½ pound or more beans in one session you should consider water quenching. Commercial roasting companies that drench the coffee after roasting to increase its weight have given water quenching a bad name, but all experiments I have conducted indicate that water quenching, performed properly, increases the cup quality of the coffee.
The water-quenching procedure has an added virtue: it reduces the volume of smoke released by the just-roasted beans. However, it is important that the water quenching be performed immediately after roasting, sparingly, and with care. No more water must be used than will evaporate almost instantly from the hot beans. Coffee that has been allowed to sit in droplets of moisture during cooling will stale rapidly in the days that follow.
WHAT YOU NEED
• Trigger-spray bottle with adjustable nozzle.
• Two colanders that are large enough to accommodate about twice the volume of green beans you intend to roast.
PROCEDURE
• Fill trigger-spray bottle with distilled or filtered water.
• Adjust nozzle to as fine a spray as possible.
• Prepare bottle before beginning roasting and have it and colanders close at hand.
• Apply water immediately after dumping beans from roasting chamber into one of two colanders.
• Holding bottle 6 to 10 inches from hot beans, apply a single short (1-second) burst of water to beans while stirring or tossing them in colander. See illustration here.
• Wait a second or two to allow water to evaporate from surface of hot beans, then apply a second short burst and wait a second or two again. Repeat intermittent bursts while stirring or tossing beans. Repeat only as long as water continues to vaporize upon contact with beans. Normally this will be about one short burst of spray per 1 to 2 ounces of beans.
• Do not attempt to completely cool beans with water. Your goal is to initiate cooling with a quick application of water, then finish cooling by stirring or tossing. If in doubt stop spraying sooner rather than later.
• Transfer beans, which still will be hot, to second dry colander. Stir or toss them until they are merely warm. Some moisture may remain beaded on surface of beans immediately after quenching, but if you have performed procedure with restraint this moisture will evaporate well before beans are cool.
Chaff Removal after Roasting
Most green coffee beans are delivered with fragments of the inner, silver skin of the fruit still adhering to them. During roasting these fragments dry and loosen, turning into roasting chaff. Decaffeinated beans retain no chaff. Other beans may retain more or less chaff depending on whether they have been subjected to a final cleaning procedure during processing, called polishing.
All manufactured-from-scratch devices remove chaff during roasting and deposit it in a chaff collector, which must be emptied between roast batches. Hot-air corn poppers pressed into service as coffee roasters also blow the chaff off the roasting beans and deposit it into a bowl situated next to the popper.
With other improvised methods the recommended cooling procedure—tossing the beans in a colander—will remove most of the loose chaff. Colanders with larger, slotlike openings will evacuate chaff more effectively than colanders with smaller, circular openings. Occasionally swirling the beans around the inside of the colander with a circular motion will help free the more stubborn chaff fragments.
If you water quench, first quench, then focus on removing the chaff as you toss the beans in the second dry colander.
Occasionally a coffee will be delivered virtually covered with chaff. In this case pour the beans to and fro between two colanders, tossing and swirling them between pours. Occasionally blow on the beans as you pour them.
Do not become obsessive with this procedure. Winnow out as much loose chaff as you can without making yourself dizzy, then enjoy the coffee. Very large amounts of chaff can dampen flavor slightly, but smaller amounts have no impact whatsoever on the cup.
If the last bits of chaff bother you for cosmetic reasons, you can always pour the offending beans back and forth in front of a fan, out-of-doors.
Resting Coffee after Roasting
Coffee flavor is at its peak twelve to twenty-four hours after roasting, but don’t hesitate to enjoy freshly roasted coffee immediately.
Accommodations for Differences Among Green Coffees
All coffees roast somewhat differently. If you have been roasting one coffee regularly and you begin roasting another, do not expect it to behave exactly like the first. Older coffee (past crop, mature, vintage) tends to roast somewhat faster than a fresh (new-crop) coffee.
More important for the home roaster are the delicacy of decaffeinated coffees and the confusing color of aged and monsooned beans. Decaffeinated beans often roast dramatically (15 to 25 percent) faster than nontreated beans and must be observed with great care after pyrolysis sets in to avoid overroasting.
A second problem with decaffeinated, aged, and monsooned beans is reading their color during roasting. They all begin the roasting process anywhere from light yellow (monsooned beans) to brown (aged and decaffeinated beans). This difference in color means that you must be particularly observant if you monitor the roast by color rather than by sound and smell and that you compensate for the original color of the bean when determining when to end the roast.
Roasting Blends of Beans from Different Origins
Separate batches of beans from different origins that together make up a blend can be combined before or after roasting. It is undoubtedly best to roast the individual components of blends separately, then combine them, because every lot of green beans differs in density, moisture content, and bean size, and consequently develops at a different pace in the roaster.
If you do blend before roasting for the sake of convenience, compose the blend some days before you plan to roast it. Allowing the blended green beans to rest together helps even out moisture among them and promotes a more consistent and better-tasting roast.
The only situation in which two components of a blend absolutely must be roasted separately is in the case of blends of decaffeinated and regular beans, because decaffeinated beans often roast much more quickly than untreated beans.