Drum Roasting vs. Air Roasting?
Nothing provokes more debate in a roomful of coffee roasters than the assertion that air roasting is as good, and in some cases better than drum roasts. Of course, it’s a hopeless discussion since we are talking about a process where the final arbiter of the result is the papillae of a biased individual (i.e. subjective taste). Taste is not something that can be measured in a lab beaker or by gas spectrometry, or calculated by some formula. Drum roasting has “conventionalConventional coffee means that a coffee is not organic certified, in the coffee trader parlance. wisdom” on its side. It makes sense to any cook who simmers their sauces slowly, or faithfully oils their cast iron, that a drum roast will be inherently better. After all, it is slower, transferring heat to the coffee seed by conductionThe transfer of heat between matter. In coffee, conduction heating is contrasted with convection heating, which occurs in a moving fluid. (contact with the hot drum metal) and convection-radiance (warm airs passing through the drum). That’s a perfect blend of stovetop pan cooking and gas oven-cooking techniques. And commercial drum roasters are big, attractive, expensive, old-world-European-looking machines. Home roasters generally look to small shops perhaps thinking that drum roasting is the technique of choice among the cognoscenti. If you are going to spend 8 hours a day roasting in a shop or warehouse, it’s nice to have some good feelings for the machine you use. Air roasting has less intrinsic charm unless you are really into hair dryers. But the roast is easy to observe, the process is “clean” because there is no effluence from atmospheric gas burners, and some variables of the drum process (bean variability and ambient temperatureThe temperature in a given room or space: This term is used to describe the overall temperature in a given environment, and is an important variable in coffee...) are less of a factor. In the commercial world of quality-conscious coffee roasters, you are going to see drum roasting as the dominant technique. Only the Sivetz roaster is available for small-scale, quality air roasting. It is a great machine, but consumes a lot of power, is noisy and fire-prone without good maintenance, and has little aesthetic value. It’s a ballsy move to start a new roasting shop with a Sivetz roaster, and not many sensible people (well, ones who don’t want to lose their life savings in a business start-up) will go that route. On the large-scale end of things, factory roasters have a better mix of air and drum roasters installed, but this doesn’t bode well for the reputation of air machines. Big business likes the throughput of air roasting, which boasts roast times as low as 3.5 minutes in huge quantities, continuous roasting (not batch roasting), and less weight loss. The coffee “puffs” a bit more, the appearance is more even and attractive, and the roasts are very repeatable. It’s really big in Europe, with the firm Neuhaus-Neotec providing most of the equipment.
Air vs. Drum CuppingCupping is a method of tasting coffee by steeping grounds in separate cups for discrete amounts of ground coffee, to reveal good flavors and defects to their fullest.... Results
“Okay, Mr. Sweet Maria’s,” I hear you saying. “Enough background blathering … which is better, Drum or Air?” I casually taste the difference between drum and air roasts every single day. We compare HotTopA home drum roaster with a 9oz capacity, adjustable heat and airflow profiling, and an external cooling tray.: A home drum roaster with a 9oz capacity, adjustable heat..., Alpenrost and Probat versus the air roasters (Hearthware Precision, Freshroast, Caffe Rosto) at different restingEither the resting of parchment coffee after drying, or for the home roaster, post-roast resting.: Resting might refer to "reposo", the time after drying the parchment coffee, when... periods, as espressoA small coffee beverage, about 20 ml, prepared on an espresso machine where pressurized hot water extracted through compressed coffee.: In its most stripped-down, basic form, this is... and as french pressA simple coffee brewer also called a Press Pot: grounds and hot water are added to a carafe, allowed to sit for several minutes, and then a filter..., all the time. Cupping the results from a specific roaster on our stock of coffees is a combination of expected flavors, and a surprise for me; the formula that x roast method will heighten y quality, but not fully develop z quality is something I can predict, but there is always something in the cup that defies preset notions. By the time a coffee is on our list, I have cupped it as a pre-shipment and
an arrival sample, each time by drum and air roast methods with varying degrees of roast, so you would think this was all rote. But coffee has a way being endlessly counter-intuitive! It’s hard to make a drum vs. air simplification: drum roasters really can’t be spoken of as one thing – as you will see, the
HotTop (perforated drum, radiant heat transfer) cups differently than the commercial Probat (solid drum, conductive and convective heat transfer). Air roasters are more similar to each other in that they all require less time to transfer heat to the coffee charge, but some are more true “fluid-bed” type (Freshroast) while others are hybrid (HWP, Z&D, Rosto). Anyway, I set up two formal, blind cuppings as a basis for the following comments. The first was our KenyaKenya is the East African powerhouse of the coffee world. Both in the cup, and the way they run their trade, everything is topnotch.: Kenya is the East... Auction Lot AA Mika, the second was the BrazilBrazil is a coffee giant . As Frank Sinatra sang, "they grow an awful lot of coffee in Brazil".: Brazil is a coffee giant . As Frank Sinatra... Vargem Grande. I chose these to represent the range between wet-processed, bright coffees (Mika) and dry-processed, lower-toned coffees (Vargem). Also, we could evaluate the Vargem as both french press and espresso since it is suited as a straight-roast for both methods. Here are some descriptive results that show how the roast method influenced the cup character: Brazil Vargem Grande –Drum Roast In regular cup testing, the HotTop (17 min..) and the Probat (15 min.) were surprisingly different. The HotTop, with its long radiant heat transfer, was actually fairly bright and light in the top end of the cup, without the development of the deeper tones. The bodyAssociated with and sensed by mouthfeel, body is sense of weight and thickness of the brew, caused by the percentage of soluble solids in the cup, including all... was good, and the cup was floralFloral notes in coffee exemplify the connection between taste and smell. Describing the taste of a specific flower is near impossible...we always default to “it tastes like it... and peanuty. The Probat had strongly developed deep flavors of black licorice, black pepper, and bittersweetBittersweet is from the language of chocolate, and describes the co-presence of positive bittering compounds balanced by sweetness. It is directly related to caramelization, but has inputs from... chocolateA general flavor or aroma term reminiscent of chocolate. But what type? Usually described with more specifics.: Chocolate is a broad, general flavor or aroma term reminiscent of.... Yes, the HotTop roast was visibly a hair lighter, but not that much. The HotTop was my favorite Vargem cup in this group. As espresso, the aftertasteAftertaste refers to lingering residual sensations in the mouth after coffee has swallowed. It might be distinguished from "finish" which is the final sensations of the coffee while... from the Probat was outstanding in its pungency and chocolatiness. The HotTop was too bright, although the espresso aromas were the best on the table. I liked the Alp. roasts but they were a bit smoky and ashyThe smell or taste of ash, such as an ashtray, cigarette smoke, or fireplace. Often a roast defect.: A quality in aroma or flavor similar to that of... in this case, so they didn’t score as well as they should have in this cupping.
Brazil Vargem Grande –Air Roast
The Freshroast had a bright and lively cup but lacked the body of the HWP and the Rosto. All had rested for 28 hours after roasting, and the Freshroast (5 min.) body would certainly improve in another day or two. The HWP (7 min.) had a more herbalA flavor descriptor in coffee reminiscent of herbs, usually meaning aromatic, savory, leafy dried herbs. Usually, more specific descriptions are given, whether is is a floral herb, or... character than the nuttyNutty is a broad flavor term, reminiscent of nuts ... but what kind exactly?: Nutty is a broad flavor term, reminiscent of nuts. It is tied intrinsically to... HotTop roast, but overall I felt this cup was a little dull. Vargem benefits from the longer roast times and the Rosto (9 min.) had the most body of the air roasts, good balanceSuggests a harmony and proportion of qualities, and implies mildness since no one quality dominates.: Balance is both an obvious and slippery taste term. It implies a harmony..., and aromaAroma refers to sensations perceived by the olfactory bulb and conveyed to the brain; whether through the nose or "retro-nasally": The aromatics of a coffee greatly influence its..., but no notes of interest (herbal, floral, etc.). As espresso, I was surprised that the short Freshroast batch time had such good sweetnessSweetness is an important positive quality in fine coffees, and is one of five basic tastes: Sour, Sweet, Salty, Bitter, Savory (Umami). In coffee, sweetness is a highly... in the cup. The HWP had a fresh fruitiness in it that contrasted most with the wineyA taste term to describe a wine-like flavor with a similar perceived acidity and fruit, and some level of acetic acid. It is found most commonly in East... fruit in the Probat roast. This parallels the notion that drum roasts have a more “developed” roast flavor, and risk “overdevelopment” (winier fruit flavors, pungency, smokiness, compression of flavors into the deep end of the cup) if the roast times are too long. Air roasts have a brisk, lively roast tasteThe set of flavors that result from the degree-of-roast.: Roast Taste is a term we started to distinguish it from "Origin Flavor". We use the "roast taste" term... but risk “underdevelopment” (unripe fruit, gassy or baked flavors).
Kenya Mika –Drum Roast
The bottom end, we’ll call it tenor notes, of the cup were really brought to the forefront in the Probat and Alpenrost, not so much in the HotTop. This is unexpected: you expect longer roasts (HotTop) to taste overdeveloped and push all flavors into the deeper tones, muting the top range. But only in the Probat was the range of flavors deep, tarryA dark roast-related flavor of pungent, intense bittering roast flavor, reminiscent of the smell of tar. creosote-black molasses. This in combination with the aromatic enzymatic notes intrinsic to the Kenya, and blackberry-blackcurrant flavors, leads to a complexThe co-presence of many aroma and flavor attributes, with multiple layers. A general impression of a coffee, similar to judgments such as "balanced" or "structured" though perhaps mismatched cup; like an outfit where the pants are nice, and the shirt is nice, but they don’t exactly go together. This was most true with the Probat roast (a surprise), and less true with the HotTop. In either case, the cup was compressed; the top end was muted, the mid-tones and bass where punched up. This was a Kenya cup for those who like the SumatraIndonesians are available as a unique wet-hulled or dry-hulled (washed) coffees. Giling Basah is the name for the wet-hulling process in Bahasa language, and will have more body... Iskandar or AcehThe northernmost district in SumatraL Aceh District is north of North Sumatra and produces some very classic Sumatra coffees. The center of coffee in Aceh is Lake Tawar... Gold. Body was good in all cups. Once again, the Alp was a bit ashy and I fear I need to clean it better (the one I use is very old and has quite a lot of buildup in it, which might have unpurified the air in the roaster and “smoked” the coffee). I didn’t score the Alp roasts for this cupping.
Kenya Mika –Air Roast In general these roasts were lively, punchy, with a bouncy and vivid cup character. They put a spotlight on the Kenya cup quality right where it counts (in my opinion), and kept the deeper notes of the cup in better proportion to the top-end notes than the drum roasts. The HWP roasts had good balance and were my favorite. The Rosto had the fruitiness but was a bit flatter overall. The Freshroast was brighter, and the roast taste a bit less sweet and caramelly, so I scored it a little lower. Overall, floral notes were added to the aroma and flavor of the blackberryBlackberry flavor in coffee sometimes relates to slightly more developed roast levels.: Blackberry is found as a fragrance, aroma or flavor in some coffees. I find that it... fruitiness, while the mid-range flavors were sweetened to a light-brown sugar level, not too weighty to interfere with the bright notes. Body was generally .5 to .75 points less than the drum roasts. Cupping Conclusions? Drum vs. air is not black and white, and each can produce great cups in the various brew methods. I wish I could wrap this up into a neat bundle, but I can’t! More than anything, the drum roasts failed to fall into a distinct category and merged with the cup qualities of air roasts to some degree: the Probat was definitely not an air roast, but the HotTop was not so dissimilar as the Rosto and HWP (this revises my impressions of HotTop roast results a bit). I can say this for sure: all roasters produce good cups, and as a general rule (to my taste) the milder, less acidic coffees are best in drum roasts, the bright coffees are optimized in air roasts. In any case, it is always true that you need to put good green coffeeGreen coffee refers to the processed seed of the coffee tree fruit. Coffee is a flowering shrub that produces fruit. The seeds of the fruit are processed, roasted,... into the roaster to have a chance at getting really good cup quality out of it.
Sweet Maria’s Coffee
1455 64th Street, Emeryville CA 94608
web: www.sweetmarias.com
email: [email protected]
Sweet Marias Green Coffee Offerings on 8/01/03:
Central American 1 lb 2 lb 5 lb 20 lb
Costa Rican Auction Lot -El Legendario $7.50 $14.25 $33.75 $121.50
Costa Rican Tarrazu – Llano Bonito $4.70 $8.93 $20.45 $72.38
Costa Rican Tres Rios – La Laguna $4.60 $8.74 $20.01 $70.84
Costa Rican – La Magnolia $4.90 $9.31 $21.32 $75.46
Costa Rican La Minita Tarrazu $6.80 $12.92 $30.26 $108.80
Costa Rican Santa Elena “Miel” $4.70 $8.93 $20.45 $72.38
GuatemalaGuatemalan coffee is considered a top quality coffee producer in Central America. Due to our proximity to Guatemala, some of the nicest coffees from this origin come to... Antigua -La Flor del Café $5.10 $9.69 $22.19 $78.54
Guatemala Huehuetenango -El Injerto $4.90 $9.31 $21.32 $75.46
Guatemala Huehuetenango -Huixoc $4.80 $9.12 $20.88 $73.92
HondurasHonduran coffee was absent from the top ranks of the Specialty market, but that has changed. It has all the environmental factors on its side: soil, altitude, climate.... SHG – Selin Recinos $4.90 $9.31 $21.32 $75.46
Honduras Org. SHG – Sebastian Melgar $5.10 $9.69 $22.19 $78.54
Mexican OrganicGrown without the use of artificial fertilizers, herbicides, etc.: Organic coffee has been grown according to organic farming techniques, typically without the use of artificial fertilizers. Some farms... Chiapas $4.60 $8.74 $20.01 $70.84
Mexican Organic Oaxaca -El Olivo $4.60 $8.74 $20.01 $70.84
NicaraguaNicaraguan coffees from the Segovia, Jinotega, Ocotal and Matagalpa regions are nice balanced cups. They often possess interesting cup character along with body and balance, outperforming many other... Org/FT Segovia -Miraflores $4.80 $9.12 $20.88 $73.92
Nicaragua Matagalpa MaragogypeMaragogype is a mutation of Typica coffee and was discovered in Brazil. The Maragogype is a large plant with big leaves, low production and very large fruits (and... $5.20 $9.88 $22.62 $80.08
Nicaragua Matagalpa PacamaraAs the name implies, Pacamara is a large bean cultivar, a cross between Pacas and Maragogype with unique flavor properties. This variant originated in El Salvador in 1958,... 19+ $4.90 $9.31 $21.32 $75.46
PanamaPanama coffee ranges from medium quality lower altitude farms to those at 1600 - 1800 meters centered in the area of Boquete in the Chirqui district near the... Auction Lot -Elida EstateA "coffee estate" is used to imply a farm that has its own processing facility, a wet-mill. In Spanish this is called an Hacienda. A Finca (farm) does... $6.20 $11.78 $26.97 $95.48
Panama Boquette -Finca La Berlina $5.40 $10.26 $23.49 $83.16
South American 1 lb 2 lb 5 lb 20 lb
Brazil FazendaFazenda is the Portuguese word for farm, hence it is the term used in Brazil. Fazenda is not a coffee-specific term. Vargem Grande $4.60 $8.74 $20.01 $70.84
Colombian Huila SupremoA Colombian coffee grade referring to screen size of 17-18 screen. In the traditional bulk Arabica business, Supremo was the top grade Colombia, with Excelso one step below... Lot 4286 $4.40 $8.36 $19.14 $67.76
Colombian Narino -San Lorenzo $5.10 $9.69 $22.19 $78.54
Colombian Organic Mesa de Los Santos $5.10 $9.69 $22.19 $78.54
PeruPeruvian coffees have Central American brightness but in a South American coffee flavor package overall. The good organic lots do have more of a "rustic" coffee character.: Organic... Org-FT Chanchamayo $5.00 $9.50 $21.75 $77.00
African- Arabian 1 lb 2 lb 5 lb 20 lb
Ethiopian Ghimbi Lot 5025 $4.20 $7.98 $18.27 $64.68
Ethiopian Harar Horse Lot 4338 $5.00 $9.50 $21.75 $77.00
Ethiopian Organic Sidamo Dry-Process $4.50 $8.55 $19.58 $69.30
Ethiopian Yirgacheffe Lot 4452 $5.20 $9.88 $22.62 $80.08
Ethiopian Organic/FT Yirgacheffe $5.50 $10.45 $23.93 $84.70
Kenya AA Auction Lot -Mika 432 $5.70 $10.83 $24.80 $87.78
Kenya AA Auction Lot -Mbwinjeru $5.45 $10.36 $23.71 $83.93
Kenya AA Auction Lot -Rugeju 673 $6.10 $11.59 $26.54 $93.94
Tanzanian Southern PeaberryA peaberry is a green coffee "bean" that has a rounded form: Coffee is the dried seed from the fruit of a flowering tree - each fruit having... $4.90 $9.31 $21.32 $75.46
UgandaWhile Arabica was introduced at the beginning of the 1900's, Robusta coffee is indigenous to the country, and has been a part of Ugandan life for centuries. The... AA Mbale Bugisu $4.20 $7.98 $18.27 $64.68
YemenYemen has a coffee culture like no other place, and perhaps some of what we enjoy in this cup is due to their old style of trade...: Technically,... MokhaThe Yemeni type of coffee, both in terms of the family of cultivars planted there, and the general trade name.: Mokha Yemeni type of coffee, both in terms... Ismaili (Hirazi) $7.80 $14.82 $36.27 $124.80
Yemen Mokha Haimi $7.20 $13.68 $33.48 $115.20
Yemen Mokha Mattari $6.55 $12.45 $28.49 $104.80
ZimbabweZimbabwe, formerly known as lower Rhodesia until independence in 1980, has produced great coffee since production was introduced in the 1960s. Like Zambian coffees, these coffees are often... AA+ Salimba $4.80 $9.12 $20.88 $73.92
Indonesian- Indian 1 lb 2 lb 5 lb 20 lb
BaliCoffee from the Indonesian island of Bali was formerly sold mainly to the Japanese market. Perhaps it is the changing face of world economics that finds the first... Shinzan ArabicaArabica refers to Coffea Arabica, the taxonomic species name of the genus responsible for around 75% of the worlds commercial coffee crop.: Arabica refers to Coffea Arabica, the... $5.60 $10.64 $24.36 $86.24
Indian Monsooned Malabar Coehlo’s Gold $5.00 $9.50 $21.75 $77.00
Indian Pearl Mountain PeaberryThe Spanish-language term for Peaberry is the same for "snail". See Peaberry for more information on the single bean fruit of the coffee tree. A peaberry is the... $4.80 $9.12 $20.88 $73.92
JavaThere are several types of Abyssinia variety coffee, but they are not from Ethiopia but rather Indonesia. Abyssinia 3 = AB3. PJS Cramer, a Dutch plant researcher, introduced this variety... Government Estate -Blawan $4.70 $8.93 $20.45 $72.38
Papua New GuineaPapua New Guinea (PNG) occupies the eastern half of the island it shares with the Indonesian province of Irian Jaya, part of Indonesia. The two primary areas for... -Organic A $4.80 $9.12 $20.88 $73.92
SulawesiSulawesi coffees are low-acid with great body and that deep, brooding cup profile akin to Sumatra. The coffee is sometimes known as Celebes, which was the Dutch colonial... Toraja Gr. 1 -Lot 1942 $4.50 $8.55 $19.58 $69.30
Sulawesi Aged Kalossi Toraja $6.00 $11.40 $26.10 $92.40
Aged Sumatra MandhelingA trade name used for wet-hulled Sumatra coffees. It is an area and a culture group as well (spelled Mandailing often) but there is not as much coffee... $5.80 $11.02 $25.23 $89.32
Sumatra Aceh Gold Super-Prep $5.00 $9.50 $21.75 $77.00
Sumatra Iskandar Triple-Pick $5.30 $10.07 $23.06 $81.62
Sumatra Mandheling DP Lot 8809 $4.50 $8.55 $19.58 $69.30
Islands- Blends -Etc. 1 lb 2 lb 5 lb 20 lb
HawaiiThe Kona district on the big island of Hawaii produces the best coffee from this state - clean, sweet and mild. : Ah, Hawaii... what a nice place.... Kona-Greenwell Farms ’02 $15.00 $28.80 $69.75 5 lb limit
Hawaii Kona- Kowali Extra Fancy $16.10 $30.91 $74.87 $257.60
SM’s Moka Kadir Blend $5.60 $10.64 $24.36 $86.24
SM’s Espresso Monkey Blend $5.00 $9.50 $21.75 $77.00
SM’s Classic Italian Espresso Blend $4.80 $9.12 $20.88 $73.92
SM’s Decaf Espresso Blend $5.60 $10.64 $24.36 $86.24
SM’s Liquid Amber Espresso Blend $5.30 $10.07 $23.06 $81.62
SM’s French RoastSugars are heavily caramelized (read as burned) and are degraded; the woody bean structure is carbonizing, the seed continues to expand and loose mass, the body of the... Blend $5.00 $9.50 $21.75 $77.00
SM’s Roasted French ChicoryChicory was a popular coffee substitute and economizer for 2 centuries, back when coffee was more prized, and pure coffee was a luxury. : Chicory was a popular... $4.80 $9.12 $20.88 $73.92
Decafs 1 lb 2 lb 5 lb 20 lb
African Highland WP Decaf Blend $5.50 $10.45 $23.93 $84.70
Brazil Prima Qualita WP Decaf $4.60 $8.74 $20.01 $70.84
Colombian Santa Isabella WP Decaf $5.00 $9.50 $21.75 $77.00
Costa Rican Monte Crisol WP Decaf $5.10 $9.69 $22.19 $78.54
Ethiopian Harar Horse WP Decaf $5.50 $10.45 $23.93 $84.70
Ethiopian WP Decaf -Sidamo DP $5.00 $9.50 $21.75 $77.00
Kenya AA WP Decaf $5.50 $10.45 $23.93 $84.70
Mexican Esmeralda Natural Decaf $4.40 $8.36 $19.14 $67.76
Sulawesi Toraja WP Decaf $5.10 $9.69 $22.19 $78.54
Sumatra WP Decaf $5.20 $9.88 $22.62 $80.08
Premium Robustas 1 lb 2 lb 5 lb 20 lb
Uganda RobustaAteng is a common name for Catimor coffees widely planted in Sumatra and other Indonesia isles.: Ateng, with several subtypes, is a common name for Catimor coffees widely... -Nanga Farms $4.00 $7.60 $17.40 5 lb limit
