The Coffee Glossary

A desirable bright, lively quality in coffee, perceived on the sides of the tongue. Not pH acidity. Described as citric, malic, phosphoric, or tartaric depending on the acid compound present. Higher-grown Arabicas typically have more acidity. Acidity decreases as roast level increases.

A manual plastic brewing device invented by Alan Adler in 2005. Uses air pressure to push water through a bed of coffee. Produces a concentrated, low-acidity brew in 1 to 2 minutes. The annual AeroPress Championship is one of specialty coffee's most popular competitions.

Italian for "drowned." A scoop of vanilla gelato or ice cream with a shot of hot espresso poured over it. A dessert, not a coffee drink, in Italian tradition.

A near-infrared spectrophotometer that measures roast color on a 0 to 100 scale (higher is lighter). The SCA standard for roast color classification. Measured on whole bean and ground samples. Being replaced by ColorTrack in newer equipment, but the Agtron scale remains the industry reference.

Roasting method using a stream of hot air (fluid bed) to agitate and heat coffee beans. Produces very even roasts with no scorching from drum contact. Sivetz is the pioneer of commercial fluid bed roasting.

Elevation at which coffee is grown, typically expressed in meters above sea level (masl). Higher altitude (1,400 to 2,000+ masl) produces denser beans with more complex acidity due to slower cherry maturation. SHB (Strictly Hard Bean) and SHG (Strictly High Grown) are grading terms for high-altitude coffee.

Espresso diluted with hot water to approximate the strength of drip coffee. Origin story: American soldiers in Italy during WWII diluted espresso to match what they were used to.

Coffee cherry or mucilage fermented in sealed, oxygen-free containers. Produces distinct flavor profiles: boozy, tropical, candy-like. Borrowed from wine fermentation techniques. Increasingly common in competition and specialty lots.

Coffea arabica. Accounts for 60 to 70% of global production. Self-pollinating tetraploid (44 chromosomes). Native to the highland forests of southwestern Ethiopia. Requires 1,000 to 2,000mm rainfall and 15 to 24 C temperatures. Susceptible to leaf rust. All commercial Arabica varietals descend from very few genetic ancestors, making the species dangerously genetically narrow.

An interspecific hybrid between Arabica and Robusta, created through artificial crossing. Combines Arabica flavor with Robusta disease resistance. The Timor Hybrid is the most important natural Arabusta, found on the island of Timor in the 1920s. Parent of Catimor, Sarchimor, and other modern disease-resistant cultivars.

The smell of brewed coffee. Distinguished from fragrance (smell of dry grounds). Aroma is evaluated immediately after brewing and contributes significantly to perceived flavor. Coffee contains over 800 volatile aromatic compounds.

A dry, puckering mouthfeel similar to unripe fruit or strong black tea. Caused by polyphenolic compounds binding to salivary proteins. Generally considered a defect in coffee when pronounced.

A catimor hybrid widely grown in Sumatra, Indonesia. Developed for disease resistance. Flavor is less complex than Typica or Bourbon but production is reliable. Common in Gayo and Lintong coffees.

A sale method for premium coffee lots. Cup of Excellence auctions are the most prominent, with lots scoring 86+ cupped by international juries and sold to the highest bidder online. Prices can exceed $100/lb for top lots.

Cleaning an espresso machine by running detergent solution through the group head with a blind (sealed) portafilter basket. Removes coffee oils and residue from the shower screen and three-way valve. Should be done daily on commercial machines.

A roast defect. Flat, dull, bread-like flavor with no sweetness. Caused by RoR dropping too low during the roast, stalling chemical reaction momentum. The bean spends too long at moderate temperatures.

The harmonious interplay of acidity, sweetness, body, and flavor in a cup. A balanced coffee has no single attribute that dominates. Balance is one of the ten attributes scored on the SCA cupping form.

Filipino term for Liberica coffee, grown primarily in Batangas and Cavite provinces of the Philippines. Strong, smoky, with a distinctive aroma. An important part of Filipino coffee culture, threatened by urbanization and low commodity prices.

A person who prepares and serves coffee, particularly espresso-based drinks. From the Italian word for bartender. The role has evolved from simple drink preparation to a skilled craft profession with international competitions.

Coffee brewed in bulk using an automatic drip brewer, typically 1.5 to 3 liters at a time. SCA-certified batch brewers meet specific water temperature and contact time standards. Batch brew has been rehabilitated in specialty coffee as a consistent, efficient method.

Spanish term for a coffee processing mill, particularly in Central America. Where cherry is received, depulped, fermented, washed, and dried. Can refer to wet mill, dry mill, or both.

A grinder that uses spinning blades to chop coffee beans. Produces extremely uneven particle sizes (fines and boulders). Universally considered inadequate for quality coffee preparation. Burr grinders are always preferred.

A mixture of coffees from different origins or processes, combined to create a specific flavor profile. Blends can be pre-roast (blended green, roasted together) or post-roast (roasted separately, blended after). Espresso blends are designed for consistency and balance across milk-based drinks.

The initial wetting of coffee grounds with a small amount of water (typically 2x the coffee weight). CO2 trapped in the roasted cells escapes rapidly, causing the bed to swell and bubble. Bloom indicates freshness: stale coffee does not bloom. The bloom allows CO2 to exit before full extraction begins, improving evenness.

Coffee grown in the Blue Mountains of Jamaica (above 910m). Protected geographical indication. One of the most expensive and sought-after coffees. Mild, balanced, with almost no bitterness. Historically popular in Japan, which imports over 80% of the crop.

The tactile sensation of weight and texture of coffee in the mouth. Ranges from tea-like (light) to syrupy (heavy). Created by dissolved solids, oils, and suspended fine particles. Dark roasts tend toward heavier body. Melanoidins from the Maillard reaction contribute significantly to body.

A natural mutation of Typica that occurred on Bourbon Island (now Reunion) in the early 1700s. One of the two ancestral Arabica varietals. Produces sweet, complex coffee with good body. Many sub-varietals exist: Red Bourbon, Yellow Bourbon, Orange Bourbon, Pink Bourbon. Lower yield than modern hybrids but prized for cup quality.

The ratio of coffee to water by weight. A common starting point for filter coffee is 1:16 (1 gram of coffee to 16 grams of water). Espresso ratios are typically 1:1.5 to 1:2.5. Adjusting the ratio changes strength and extraction.

A positive descriptor for pronounced, pleasant acidity. Often associated with high-grown washed African coffees. Citrus, berry, and floral brightness are common descriptors.

A grinder that uses two abrasive surfaces (burrs) to crush coffee beans to a uniform particle size. Flat burrs produce bimodal particle distribution; conical burrs produce unimodal. Burr material (steel, ceramic, titanium-coated), size (54mm to 98mm for espresso), and alignment determine grind quality.

Water that passes through the coffee bed without extracting soluble material, either through channels or around the edges of the filter. Also: intentionally diluting a concentrated brew with clean water (as in bypass brewing or Americano preparation).

The New York Intercontinental Exchange (ICE) futures market for Arabica coffee, traded as "KC" (Coffee C). The global benchmark price for commodity Arabica. Quoted in US cents per pound. Does not reflect quality, only supply and demand. Specialty coffee typically trades at a premium above C-market price.

Traditional Mexican coffee brewed in an unglazed clay pot (olla de barro) with piloncillo (unrefined cane sugar) and canela (cinnamon). The clay imparts an earthy character. A pre-colonial pottery tradition meeting colonial-era coffee.

A xanthine alkaloid (C8H10N4O2). Coffee's primary psychoactive compound. Arabica contains 1.0 to 1.5% caffeine by dry weight; Robusta contains 1.7 to 4.0%. Caffeine evolved as an insect deterrent. It blocks adenosine receptors in the human brain, promoting alertness. Half-life in humans: 3 to 7 hours, highly variable by genetics (CYP1A2 enzyme).

The process of aligning cupping scores among a group of tasters. Before a cupping session, tasters cup the same coffees and compare scores. Discrepancies are discussed until the group reaches consensus on how to apply the scoring rubric. Essential for competition judging and Q-grading.

Coffea canephora, commonly known as Robusta. A diploid species (22 chromosomes) native to central and western Sub-Saharan Africa. Higher caffeine, lower acidity, more body than Arabica. Used in espresso blends for crema and body. Vietnam is the largest producer.

Equal parts espresso, steamed milk, and milk foam, traditionally served in a 150 to 180ml cup. Named after the Capuchin friars, whose brown robes match the color. In Italy, cappuccino is a morning drink. Ordering one after 11am or after a meal is a tourist marker.

A processing technique borrowed from wine (Beaujolais). Whole coffee cherries are placed in sealed containers filled with CO2. Intracellular fermentation occurs without oxygen. Produces intensely fruity, wine-like flavors. Used for competition and specialty lots.

The dried skin and pulp of the coffee cherry, used to make a tea-like infusion. Contains caffeine (about 25% as much as brewed coffee). Flavor ranges from rosehip to cherry to hibiscus. Regulatory status varies by country (classified as a "novel food" in the EU until 2022).

A Colombian varietal developed by Cenicafe (Colombian coffee research center). Resistant to coffee leaf rust. Replaces the more susceptible Caturra in many Colombian farms. Cup quality is debated in specialty circles but improving with each generation.

A cross between Caturra and Timor Hybrid (itself a natural cross between Arabica and Robusta). Developed for leaf rust resistance. High yield but historically lower cup quality due to Robusta genetics. Common in Asia and parts of Central America.

A cross between Mundo Novo and Caturra, developed in Brazil. Compact plant, high yield, good cup quality. Widely planted in Brazil and Central America. Red Catuai and Yellow Catuai refer to the color of the ripe cherry.

A Brazilian cultivar, a cross between Catuai and Icatu. Disease-resistant with good cup quality. Part of Brazil's ongoing breeding program to combine productivity with resilience.

A natural mutation of Bourbon discovered in Caturra, Brazil in 1937. Compact plant, high yield, good cup quality. Susceptible to leaf rust. Widely planted in Colombia and Central America. The base for many modern hybrids.

The papery silver skin that separates from the coffee bean during roasting. Extremely lightweight, carried away by airflow in the roaster. Must be collected (fire hazard). In espresso preparation, chaff particles occasionally appear on the surface of the puck.

Uneven water flow through a coffee bed, where water finds a path of least resistance and flows predominantly through that channel. In espresso, channeling causes some coffee to be over-extracted and some under-extracted simultaneously. Caused by uneven distribution, inconsistent tamp, or too-fine grind.

The formation of preferential water pathways through an espresso puck. Water follows the path of least resistance, over-extracting some areas and under-extracting others. Results in an unbalanced, often sour-and-bitter shot. Diagnosed by uneven flow from a bottomless portafilter. Prevented by even distribution and consistent tamping.

The drum or air temperature at the moment green coffee is loaded into the roaster. Determines the initial rate of heat transfer. Too high causes scorching and tipping; too low causes a sluggish start and extended drying phase.

An hourglass-shaped glass pour-over brewer invented by Peter Schlumbohm in 1941. Uses proprietary thick paper filters that remove oils and fine particles, producing an exceptionally clean, bright cup. In the permanent collection of the Museum of Modern Art. The leather and wood collar is its trademark.

The fruit of the coffee plant. A drupe (stone fruit). Outer skin (exocarp), pulp (mesocarp), mucilage (pectin layer), parchment (endocarp), silver skin (spermoderm), and the seed (endosperm, which is the coffee bean). Most cherries contain two seeds; peaberries contain one.

A family of polyphenolic compounds making up 6 to 10% of green coffee by dry weight. The primary source of perceived acidity in coffee. Broken down during roasting (darker roast = less chlorogenic acid = less perceived acidity). Also a potent antioxidant. Robusta contains more chlorogenic acid than Arabica.

Cost, Insurance, and Freight. An international trade term (Incoterm) where the seller pays shipping and insurance to the destination port. CIF prices are higher than FOB prices because they include transport costs.

An extremely light roast, stopped before or just at first crack. Named for the light brown color. Very high acidity, grain-like, sometimes grassy. Uncommon in commercial coffee. Used in cupping to evaluate green quality.

A medium roast, reached shortly after first crack ends. Named from New York City roasting tradition. Good balance of origin character and roast development. Agtron approximately 55 to 65.

A slightly darker medium roast, between City and Full City. More development time after first crack. More body, more caramel sweetness, slightly less acidity than City.

A cup with no defect flavors from first sip through finish. One of ten attributes on the SCA cupping form. Absence of faults: no ferment, no phenol, no baggy, no chemical off-flavors. Clean cup is binary: it is either clean or it is not.

Supercritical CO2 decaffeination. CO2 at 31.1 C and 73.8 atm becomes supercritical: liquid density, gas diffusivity. Highly selective for caffeine. Preserves flavor compounds well. The most expensive commercial decaf method.

Coffee brewed with cold or room temperature water over 12 to 24 hours. Produces a smooth, low-acidity concentrate. Extraction is driven by time rather than temperature. Certain volatile compounds present in hot brew are absent in cold brew, giving it a fundamentally different chemical profile, not just a cooler version.

A modern roast color measurement system using near-infrared spectroscopy. Successor to Agtron. Measures both whole bean and ground samples. Increasingly standard in commercial roasting for quality control and consistency.

Coffee traded as an undifferentiated product on futures exchanges. Priced by the C-market without regard to quality differences. Typically scored below 80 on the SCA scale. Accounts for approximately 75 to 80% of global coffee trade.

A positive descriptor indicating multiple flavor notes that shift and evolve across the palate and as the coffee cools. Complexity is associated with high-quality, high-altitude, well-processed coffees.

A type of grinder burr with a cone-shaped inner burr rotating inside a ring-shaped outer burr. Produces a unimodal particle distribution. Runs at lower RPM than flat burrs, generating less heat. Preferred for espresso by some for its fuller body and lower fines production.

A farmer-owned organization that collectively processes, markets, and sells coffee. Members share infrastructure (washing stations, dry mills) and negotiate as a group for better prices. Common in Ethiopia, Rwanda, Colombia, and Central America.

Espresso "cut" (cortado means "cut" in Spanish) with a roughly equal amount of warm steamed milk. Served in a small glass, typically 120 to 140ml. Originated in Spain. Reduces the intensity of espresso while preserving its flavor.

Spanish for "cut." Espresso cut with a roughly equal amount of warm steamed milk. Served in a small glass, 120 to 140ml. The milk reduces espresso intensity without masking it. A staple of Spanish and Latin American coffee culture.

An audible popping sound at approximately 196 C bean temperature. Steam pressure inside the bean ruptures cell walls. Marks the transition from endothermic to exothermic reactions. The beginning of the development phase. Similar sound to popcorn popping.

A quieter, more rapid crackling sound at approximately 224 C bean temperature. CO2 pressure fractures the now-brittle cell structure. Oils migrate to the bean surface. Marks the threshold of dark roasting. Many specialty roasters stop well before second crack.

The golden-brown emulsion layer on top of a properly extracted espresso shot. Created by pressurized CO2 (from the roasting process) combining with oils and surfactants. Crema color, thickness, and persistence are visual indicators of freshness, grind, and extraction quality. First produced by Gaggia's lever machine in 1948.

A cultivated variety, selected and maintained through deliberate breeding. Distinct from varietal (a naturally occurring variant). In coffee, the terms are often used interchangeably, though technically Castillo is a cultivar (bred by Cenicafe) while Bourbon is a varietal (natural mutation).

An annual competition and auction program run by the Alliance for Coffee Excellence (ACE). Coffees are blind-cupped by national and international juries. Lots scoring 86+ are auctioned online to the highest bidder. The most prestigious quality competition in the coffee industry.

An annual quality competition and auction organized by the Alliance for Coffee Excellence. Coffees are blind-cupped by national and international juries. Winners (scoring 86+) are auctioned online. The highest-scoring lot often sets record prices. The most prestigious quality recognition in specialty coffee.

The standardized method for evaluating coffee quality. SCA protocol: 8.25g coffee to 150ml water at 200 F, steeped 4 minutes, crust broken, evaluated for fragrance/aroma, flavor, aftertaste, acidity, body, balance, uniformity, clean cup, sweetness, and overall impression. Scored on a 100-point scale. 80+ is specialty grade.

A specialized deep, round spoon used for cupping. The bowl shape allows the taster to slurp coffee forcefully, aerating it across the palate. Usually stainless steel or silver-plated. Every Q-Grader carries one.

Coffee roasted to or beyond second crack. Bean surface is oily. Low acidity, heavy body, bitter-sweet, smoky. Origin character is largely replaced by roast character. Agtron 25 to 45. Suitable for espresso blends and milk-based drinks where roast flavor cuts through dairy.

Coffee with 97% or more of its caffeine removed (US FDA standard) or 99.9% (EU standard). All decaffeination happens to green (unroasted) coffee. Methods include Swiss Water Process, supercritical CO2, methylene chloride, and ethyl acetate. See the Roast Chemistry page for detailed comparison.

An undesirable flavor or physical characteristic. Flavor defects include ferment, phenol (medicinal/chemical), Rio (iodine-like), and baggy. Physical defects include quakers, insect damage, broken beans, and foreign material. The SCA Green Coffee Classification counts defects per 350g sample.

The release of CO2 from freshly roasted coffee. Roasted beans release approximately 10ml of CO2 per gram over the first two weeks. Excessive CO2 interferes with extraction (creates turbulence and channeling). Most coffees taste best 7 to 21 days after roasting. Espresso may need longer rest (10 to 30 days) due to the sensitivity of pressurized extraction.

Mechanical removal of the mucilage layer from the coffee seed after depulping. An alternative to fermentation. Faster but removes all mucilage uniformly, whereas fermentation allows variable flavor development. Common in large-scale operations.

Separating green coffee beans by density using a gravity table (Oliver table). Denser beans are generally higher quality (more sugars, better flavor development during roasting). Less dense beans (quakers, insect-damaged, underdeveloped) are removed. A key quality control step at the dry mill.

Removing the outer skin and pulp from the coffee cherry, exposing the mucilage-covered parchment. Done mechanically with a depulper. The first step in washed processing. Timing after harvest matters: depulping within 8 hours of picking is standard for quality.

A Colombian decaffeination company based in Manizales. Specializes in ethyl acetate (sugarcane) decaffeination. The largest EA decaf processor in the world. Their proximity to both sugarcane and coffee farms gives them a unique supply chain advantage.

The time elapsed after first crack to the end of the roast. Also called post-crack development. Measured as a percentage of total roast time (DTR, Development Time Ratio). Typical range: 15 to 25%. Controls the balance between origin character (shorter) and roast character (longer).

The process of adjusting grind size, dose, yield, and time to achieve optimal espresso extraction. Variables are interdependent: changing one affects all others. A new bag of coffee typically requires re-dialing. The process combines measurement (scale, timer, refractometer) with sensory evaluation.

A purchasing model where roasters buy directly from producers, bypassing intermediary exporters and importers. No certifying body or formal standard (unlike Fair Trade). Price premiums, farm visits, and long-term relationships are typical. Transparency and quality focus distinguish it from commodity buying.

The process of evenly spreading ground coffee in an espresso portafilter basket before tamping. Methods include: WDT (needle distribution), Stockfleth's move (palm rotation), and leveling tools (OCD, ONA, Duomo). Even distribution prevents channeling.

The weight of dry coffee used for a brew. In espresso, typically 14 to 22g depending on basket size. In filter, the SCA recommends 55g per liter (+/- 10%). Dose is the starting variable from which other parameters are calculated.

The phase in pour-over brewing after all water has been added, when gravity pulls the remaining water through the coffee bed. Total drawdown time is influenced by grind size, filter type, and pouring technique. SCA recommends total contact time of 4 to 6 minutes for drip.

A brewing method where hot water flows through a bed of ground coffee by gravity, through a paper or metal filter. The most common brewing method worldwide. Batch drip brewers automate the process; manual pour-over gives the brewer control over flow rate and pour pattern.

The most common commercial roasting method. Beans tumble in a heated rotating metal drum. Heat transfer is a combination of conduction (drum wall), convection (hot air), and radiation. Drum size ranges from 1kg sample roasters to 300kg+ production machines.

The facility where dried parchment coffee is hulled, sorted, graded, and bagged for export. Operations include hulling (removing parchment), polishing, density sorting (gravity tables), size grading (screens), and color sorting (optical sorters). The last stop before export.

Reducing the moisture content of processed coffee to 10 to 12% for storage stability. Methods: sun drying on patios or raised beds (traditional), mechanical drying in rotating drums (faster, less weather-dependent), or a combination. Drying speed and evenness directly affect cup quality. Too fast causes cracking; too slow risks mold and ferment.

A raised structure (usually mesh stretched over a wooden frame) used to dry coffee. Also called African beds or raised beds. Allows air circulation above and below the coffee, promoting even drying. Coffee is turned regularly for 10 to 30 days depending on method and climate.

An espresso machine group head design created by Faema in 1961. Uses a thermosyphon circulation system to maintain temperature stability. The E61 group became an industry standard and is still used in many home and commercial machines. Named for the solar eclipse of 1961.

The seed tissue that stores nutrients. In coffee, the endosperm is the bean itself. The green coffee bean is the endosperm of the coffee cherry seed, which is roasted and brewed.

A reaction that absorbs heat from its surroundings. The first phase of roasting is endothermic: the bean absorbs thermal energy to drive off moisture and initiate chemical changes. The transition to exothermic occurs around first crack.

Coffee brewed by forcing hot water (90 to 96 C) through finely ground coffee at 6 to 9 bar of pressure for 25 to 35 seconds. Produces a concentrated 25 to 45ml shot with crema. Invented in Italy, refined by Gaggia (1948). The base for cappuccino, latte, cortado, and most cafe drinks. Not a roast level; any coffee can be brewed as espresso.

A combination of coffees specifically formulated for espresso preparation. Typically designed for balance, sweetness, and body across a range of milk-based drinks. May include both Arabica and Robusta components. Blended to taste consistent year-round despite seasonal crop changes.

A commodity exchange in Addis Ababa that handles the majority of Ethiopian coffee exports. Coffee is graded and traded through the ECX, which has been criticized for reducing traceability (lots from many farms are blended). Recent reforms allow some cooperatives and private farms to export directly, improving specialty traceability.

A catch-all term for the thousands of unnamed Arabica varietals growing in Ethiopia. Most Ethiopian coffee is a mix of wild and semi-wild varietals, not planted cultivars. Genetic diversity is enormous. True varietal identification requires DNA analysis. The JARC (Jimma Agricultural Research Center) has cataloged some, but thousands remain uncharacterized.

Now classified as a variety of Coffea liberica (Coffea liberica var. dewevrei). Grown primarily in Southeast Asia. Tart, fruity, complex flavor profile. Accounts for less than 1% of global production. Sometimes used in blends for complexity.

A reaction that releases heat. After first crack, the coffee bean becomes exothermic: the Maillard reaction and caramelization generate heat faster than the bean absorbs it. The roast can accelerate on its own if the roaster does not reduce energy input.

Coffee that meets the minimum quality standards for export from its country of origin. Standards vary by country. In Ethiopia, grades 1 to 5 are export grade. In Colombia, Excelso and Supremo are export grades. Not all export-grade coffee is specialty grade.

The process of dissolving soluble compounds from ground coffee into water. Measured as extraction yield: the percentage of dry coffee mass dissolved. Typical target: 18 to 22%. Under-extracted coffee (below 18%) tastes sour and thin. Over-extracted coffee (above 22%) tastes bitter and astringent. Not all compounds extract at the same rate: acids first, sugars second, bitter compounds last.

The percentage of the dry coffee dose that dissolves into the brew water. Calculated: (TDS% x total brew weight in grams) / dose in grams. Optimal range: 18 to 22% for most methods. Below 18%: under-extracted (sour, thin). Above 22%: over-extracted (bitter, astringent, dry). The universal metric for brew quality.

A certification system guaranteeing a minimum purchase price to cooperatives, currently $1.80/lb for washed Arabica (with a $0.30/lb premium above C-market if higher). Also requires a $0.20/lb social premium for community investment. Certified by Fairtrade International (FLO). Requires cooperative structure; individual farms cannot be Fair Trade certified.

Portuguese for farm or estate. Used in Brazil to describe large coffee plantations. Some Brazilian fazendas are thousands of hectares. Fazenda names often appear on single-estate specialty Brazilian coffees.

As a defect: an unpleasant sour, vinegary, or rotting flavor caused by uncontrolled microbial activity during processing. As a process: controlled fermentation is deliberately used in washed, honey, natural, and anaerobic processing to develop desirable flavors.

Microbial decomposition of the mucilage layer. In washed processing, cherries are depulped and then fermented in tanks for 12 to 72 hours. Microbes (yeasts, bacteria) break down the pectin-rich mucilage. Water temperature, pH, and duration all affect flavor. Controlled fermentation is the frontier of coffee processing innovation.

Any brewing method that separates grounds from the liquid through a filter medium: paper, metal mesh, or cloth. Paper filters remove oils and fine particles, producing a cleaner cup. Metal filters allow oils and fines through, producing a fuller-bodied cup. Cloth (nel) filters are between the two.

Spanish for farm or estate. Used throughout Latin America. Finca names are used for farm-specific specialty lots. "Finca El Injerto" (Guatemala) and "Finca Deborah" (Panama) are examples of fincas famous for exceptional coffee.

Hot coffee brewed directly over ice. Also called Japanese iced coffee. Hot water extracts aromatics that cold brew misses, and the immediate chilling locks in volatile compounds. Uses approximately half the normal water volume, with the other half as ice. Produces a brighter, more aromatic iced coffee than cold brew.

A negative descriptor. A cup lacking in acidity, aroma, and complexity. Often associated with baked roasts, stale coffee, or low-quality green. The opposite of bright or complex.

A type of grinder burr with two parallel disc-shaped burrs. Produces a bimodal particle distribution (two peaks: fines and target size). Runs at higher RPM than conical burrs. Preferred by many competition baristas for the clarity and sweetness in the cup.

Espresso with microfoamed milk, served in a 150 to 180ml cup. Originated in Australia or New Zealand (both claim it). Distinguished from a latte by smaller volume and a thinner, velvety microfoam layer rather than a frothy top. The milk texture is the defining characteristic.

A visual reference tool mapping coffee flavors from general categories (fruity, nutty, chocolatey) to specific descriptors (blueberry, hazelnut, dark chocolate). The SCA/WCR (World Coffee Research) Flavor Wheel, published in 2016, is the industry standard. Based on the World Coffee Research Sensory Lexicon.

A roasting method where hot air suspends and agitates the beans, eliminating direct contact with heated surfaces. Produces very even roasts. Michael Sivetz pioneered the technology for commercial coffee roasting. Also called air roasting.

Free on Board. An international trade term where the seller delivers coffee to the port of origin, and the buyer assumes cost and risk from that point. FOB price is the standard reference for green coffee pricing in specialty trade. Higher than farmgate price (FOB includes milling, transport to port, and export fees).

The smell of dry ground coffee before water is added. Distinguished from aroma (smell after brewing). Fragrance is the first attribute evaluated in a cupping. Fresh, well-roasted coffee has a strong, pleasant fragrance; stale coffee has muted or papery fragrance.

An immersion brewer with a metal mesh plunger filter. Coffee steeps in hot water for 3 to 5 minutes, then the plunger is pressed to separate grounds from liquid. Produces a full-bodied, oily cup because the metal mesh allows oils and fine particles through. Also called cafetiere or press pot.

A very dark roast, well into second crack. Beans are very oily. Smoky, burnt-sugar, thin-bodied (oils on the surface reduce body). Almost no origin character remains. The name comes from 19th-century French roasting preferences, not modern French coffee culture.

A medium-dark roast at the onset of second crack. Rich, full-bodied, with balanced bittersweet and origin character. Agtron approximately 45 to 55. A common profile for espresso single-origins.

See Washed Process. Cherries are fully depulped, fermented, and washed before drying. The cleanest, most transparent processing method. Highlights terroir and varietal character.

Contracts to buy or sell coffee at a set price on a future date. Traded on the ICE exchange (Arabica) and LIFFE/ICE London (Robusta). Used by producers, exporters, importers, and roasters to hedge against price volatility. Speculators also trade coffee futures without intending physical delivery.

A varietal collected from the forest near the town of Gesha in southwestern Ethiopia. Planted in Panama by the Peterson family at Hacienda La Esmeralda. Won Best of Panama in 2004 and redefined auction pricing. Flavor profile: jasmine, bergamot, tropical fruit, tea-like body. Extremely expensive. Now grown in Colombia, Costa Rica, Ethiopia, and elsewhere.

A farm and genetic conservation project in the Bench Maji zone of southwestern Ethiopia, near the town of Gesha. Founded to preserve and study wild Gesha varietals in their native habitat. Produces some of the most expensive and sought-after coffees in the world.

A precision restrictor (small orifice) in an espresso machine that controls water flow rate to the group head. Size affects pre-infusion duration and extraction dynamics. Typically 0.5 to 1.0mm diameter.

Wet-hulling. A processing method unique to Sumatra and parts of Indonesia. Parchment is removed while the bean is still at 30 to 50% moisture (versus 10 to 12% in standard processing). Produces the earthy, herbal, low-acidity profile characteristic of Sumatran coffee. The high moisture at hulling gives the bean its distinctive blue-green color.

A vibrating, tilted table used in the dry mill to sort coffee beans by density. Beans travel across the table; heavier (denser) beans move to one side, lighter beans to the other. A critical quality sorting step.

The raw, unroasted coffee seed after processing (washing, drying, hulling). Green beans are shelf-stable for months to years if stored at proper temperature and humidity. The commodity that is traded globally. All roasting happens at the destination country or region.

In decaffeination (Swiss Water Process): water saturated with all soluble coffee compounds except caffeine. Used to extract caffeine from green beans via osmotic pressure without removing flavor compounds.

The particle size of ground coffee, from extra-coarse (cold brew, French press) to extra-fine (Turkish, espresso). Grind size controls the surface area exposed to water and therefore the rate and extent of extraction. The single most impactful variable in coffee brewing after water quality.

The amount of ground coffee that remains inside a grinder between doses. High retention means stale grounds contaminate fresh doses. Low-retention (or zero-retention) grinders are designed to purge all grounds with each use. Important for single-dosing workflows.

The part of an espresso machine where the portafilter locks in and water is dispensed through the coffee puck. Contains the shower screen (for water distribution), gasket, and in some designs, the thermosyphon or PID-controlled heating element. E61 is the most iconic group head design.

Spanish for estate or plantation. Used in Latin America for large coffee farms. Hacienda La Esmeralda (Panama) is arguably the most famous coffee hacienda in the world.

Coffee grown at high altitude (1,200 to 1,370m in Central American grading). The slow maturation at altitude produces denser beans. SHB (Strictly Hard Bean) is grown above 1,370m. Density correlates with complexity and quality in the cup.

A processing method where the cherry skin is removed but some or all of the mucilage is left on the bean during drying. Named for the sticky, honey-like feel of the mucilage. Classified by how much mucilage is left: white honey (least), yellow, red, black honey (most). More mucilage means more fermentation, more body, and more sweetness. Popular in Costa Rica and El Salvador.

Removing the parchment layer from dried coffee beans. Done at the dry mill. In standard processing, beans are hulled at 10 to 12% moisture. In giling basah (wet-hulling), beans are hulled at 30 to 50% moisture.

A Brazilian cultivar, a complex hybrid involving Arabica, Robusta (via Timor Hybrid), and Bourbon. Disease-resistant with acceptable cup quality. Part of Brazil's long-running breeding program.

International Coffee Organization. An intergovernmental body established in 1963 under the auspices of the United Nations. Administers the International Coffee Agreement. Publishes market data, composite prices, and consumption statistics. Headquarters in London.

A brewing method where coffee grounds are fully submerged in water for a set period. French press, AeroPress, cupping, and cold brew are all immersion methods. Extraction is primarily controlled by time and temperature, not flow rate.

In espresso: a brief period of low-pressure water contact before full pressure is applied. Also called pre-infusion. Saturates the puck evenly before extraction begins, reducing channeling. Duration ranges from 2 to 10 seconds on most machines.

An extremely dark roast, nearly black. Very oily surface. Thin body, dominant carbon and ash flavors. Despite the name, most Italian espresso is roasted medium to medium-dark, not to "Italian roast" level. The term is more American than Italian.

A flat-bottom pour-over dripper made by Kalita (Japan). Three small drain holes restrict flow rate, making extraction more forgiving than the V60. Uses proprietary wave-shaped paper filters. Produces a balanced, consistent cup. Popular with beginners and professionals alike.

Coffee grown in the Kona district on the Big Island of Hawaii. Protected designation of origin. Volcanic soil, high altitude, unique microclimate. One of the most expensive coffees in the world. "Kona blend" legally requires only 10% Kona coffee in Hawaii, a persistent labeling controversy.

Espresso with steamed milk, served in a 240 to 360ml cup. Higher milk-to-coffee ratio than a cappuccino. "Latte" is simply Italian for "milk," so ordering a "latte" in Italy gets you a glass of milk. Specify "caffe latte." The latte is the foundation drink of second-wave coffee culture.

Patterns created by pouring steamed milk into espresso. Requires properly textured microfoam and a well-extracted espresso with intact crema. Basic patterns: heart, rosetta (fern), tulip. Advanced: swan, phoenix, multi-layer designs. Popularized by David Schomer (Espresso Vivace, Seattle) in the 1990s.

Coffea liberica. A species native to West Africa with large cherries and asymmetric beans. Once widely planted in Southeast Asia after the 1869 coffee rust epidemic destroyed Arabica production. Now less than 2% of global production. Distinctive smoky, woody, floral flavor. Grown primarily in the Philippines (where it is called Barako), Malaysia, and Liberia.

Coffee roasted to first crack or slightly beyond. High acidity, light body, floral, fruity, tea-like. Origin character preserved. Agtron 80 to 95. The dominant roast style in Scandinavian and progressive specialty coffee. Requires high-quality green coffee; light roasting exposes every defect.

A discrete quantity of coffee from a defined source, processed and sold together. A lot can be from a single farm, a single day's picking, or a blend from a cooperative. Micro-lots (very small, exceptional lots) and nano-lots (even smaller) are terms for premium, limited-quantity offerings.

Italian for "long." An espresso pulled with more water, typically 1:3 to 1:4 ratio (versus 1:2 for a standard shot). Produces a larger, less concentrated drink. Extracts more bitter compounds than a standard espresso due to extended contact time.

Italian for "stained" or "marked." An espresso "marked" with a small dollop of steamed milk or foam. Traditional macchiato is a 60 to 90ml drink, mostly espresso. Not to be confused with the large, flavored, milk-heavy drinks that share the name in some markets.

A chemical reaction between amino acids and reducing sugars that occurs at 140 to 165 C. The primary browning reaction in coffee roasting (and in bread, steak, and hundreds of other foods). Produces melanoidins (brown color, body), pyrazines (nutty, roasty), furanones (caramel, sweet), and hundreds of other volatile compounds. Named after Louis-Camille Maillard (1912).

Coffee from the Mandailing region of North Sumatra, Indonesia. Wet-hulled (giling basah) processed. Full body, low acidity, earthy, herbal, chocolatey. The name is a transliteration of the Mandailing people. One of the most distinctive regional styles in coffee.

A natural Typica mutation discovered in Maragogipe, Bahia, Brazil. Produces extremely large beans ("elephant beans"). Low yield, good cup quality when well-grown. The large bean size makes it visually distinctive.

Coffee roasted to mid-point between first and second crack. Balanced acidity and body. Origin and roast character in equilibrium. Agtron 55 to 65. The most commercially popular roast range. Accessible to the widest audience.

High-molecular-weight brown polymers produced by the Maillard reaction. Responsible for the brown color of roasted coffee, the body and mouthfeel in the cup, and significant antioxidant activity. Melanoidin content increases with roast level.

A very small quantity of coffee (typically under 25 bags / 1,500 kg) from a specific area of a farm, a single day of harvest, or a specific processing experiment. Micro-lots command premium prices and are the currency of specialty coffee auctions and direct trade relationships.

A small-scale processing facility operated by an individual farm or small group of farms. Allows the producer to control processing quality and create differentiated lots. The micro-mill movement in Costa Rica (starting ~2000) was pivotal in enabling farm-level specialty coffee.

As a drink: espresso with chocolate (syrup or powder) and steamed milk. As a place: al-Makha (Mocha), the Yemeni port that was the sole coffee export point for centuries. As a flavor: the natural chocolatey characteristic of some coffees, particularly Ethiopian Harrar and Yemeni origins. The word carries all three meanings.

A stovetop brewer invented by Alfonso Bialetti in 1933. Water in the lower chamber boils, steam pressure (1 to 2 bar) pushes water through ground coffee into the upper chamber. Produces a strong, concentrated brew. Not true espresso (insufficient pressure). The Bialetti Moka Express is an icon of Italian design, found in an estimated 90% of Italian households.

A post-harvest process where green coffee beans are exposed to monsoon winds and humidity in open warehouses for 3 to 4 months. The beans swell, turn pale gold, and develop a unique musty, earthy, low-acid profile. Monsooned Malabar from India is the best-known example. Originally an accidental result of long sea voyages.

The tactile sensation of coffee in the mouth. Includes body (weight), texture (silky, gritty, oily, watery), and astringency. Affected by brew method (filtered vs. unfiltered), roast level, and extraction. Distinct from flavor, which is taste + aroma.

The sticky, sugar-rich pectin layer surrounding the coffee seed, between the pulp and the parchment. Contains sugars and organic acids that feed microbial fermentation during processing. In washed processing, mucilage is removed by fermentation and washing. In honey processing, it is left partially or fully intact during drying.

A negative descriptor for a thick, dull, murky cup lacking clarity. Often caused by over-extraction, poor water quality, or dirty equipment. Can also result from too many fines in the grind passing through the filter.

A natural cross between Typica and Bourbon, discovered in Brazil. High yield, good cup quality, vigorous growth. Widely planted in Brazil. Parent of Catuai.

Also called dry process. The entire coffee cherry is dried whole on patios or raised beds for 2 to 4 weeks. The fruit ferments around the seed as it dries. Produces heavy body, pronounced sweetness, and fruity, wine-like flavors. The oldest processing method. Common in Ethiopia, Brazil, and water-scarce regions. Risk of over-fermentation if drying is uneven.

Freshly harvested and processed green coffee from the most recent harvest season. New crop coffee is preferred for its vibrant acidity and brightness. Flavor degrades over time in storage (becoming "past crop" after 12+ months). Harvest seasons vary by hemisphere and geography.

Cold brew infused with nitrogen gas under pressure, served on tap. Nitrogen creates a creamy, cascading texture similar to stout beer. No dairy needed for the creamy mouthfeel. The nitrogen gas (unlike CO2) does not dissolve easily, creating tiny, stable bubbles.

A three-hole espresso shower screen design used in some commercial machines. The number and size of holes affect water distribution across the puck. Precision screens (like IMS and VST) have become aftermarket upgrades for improved extraction evenness.

Coffee grown without synthetic pesticides, herbicides, or fertilizers, certified by an accredited body (USDA Organic, EU Organic, JAS, etc.). Requires three years of organic practices before certification. Organic certification does not guarantee quality; it certifies farming practices. Price premiums are typically $0.30 to $0.50/lb above conventional.

Dissolving too many compounds from the coffee (extraction yield above 22%). Taste: bitter, astringent, dry, hollow. Caused by grind too fine, water too hot, brew time too long, or agitation too aggressive. The bitter compounds that extract late overwhelm the sweet and acidic compounds that extracted first.

A cross between Pacas (a Bourbon mutation from El Salvador) and Maragogype. Large beans with complex, intense flavor. Created at the Salvadoran coffee research institute. Performs exceptionally at competition level.

A natural Bourbon mutation discovered in El Salvador in 1949 on the Pacas family farm. Compact plant, adapted to lower altitudes. Parent of Pacamara.

The papery endocarp surrounding the coffee bean inside the cherry. In washed processing, the bean in its parchment (called "pergamino" in Spanish) is dried to 10 to 12% moisture, then the parchment is removed by hulling at the dry mill. Parchment protects the bean during storage and transport.

Green coffee from a previous harvest season, typically over 12 months old. Flavor deteriorates: acidity fades, body becomes papery or woody, overall character flattens. Some coffees age better than others. Properly stored past crop can still be acceptable but is generally less desirable than new crop.

A flat concrete or brick surface used for drying coffee in the sun. Coffee is spread in thin layers and raked regularly for even drying. Still widely used in Brazil and parts of Central America. Less airflow than raised beds, requiring more frequent turning.

A coffee cherry that produces a single, round seed instead of the usual two flat-sided seeds. Occurs in approximately 5 to 10% of cherries. Peaberries are sorted out and sold separately, often at a premium. They roast differently (more evenly) due to their round shape. Some regions (Tanzania, Kenya) are particularly known for peaberry lots.

A brewing method where water flows through a bed of coffee grounds, as opposed to immersion where grounds are submerged. Pour-over, drip, and espresso are percolation methods. Extraction is controlled by flow rate, contact time, grind size, and water temperature.

A defect flavor resembling iodine, medicine, or bandages. Caused by the presence of phenol compounds, often from contamination (jute bags, chemical exposure) or certain Robusta genetics. A primary defect in SCA green grading.

Proportional-Integral-Derivative controller. An electronic temperature control system used in espresso machines and roasters. PID maintains brew temperature within narrow tolerances (typically +/- 1 C). A significant upgrade from thermostat-based machines where temperature swings can be 10 C or more.

Removing any remaining silver skin from green coffee beans after hulling. A cosmetic step at the dry mill. Polished beans look cleaner but the process does not affect flavor. Some buyers consider polishing a sign of care; others consider it unnecessary.

The handled device that holds the filter basket in an espresso machine. Locks into the group head. Comes in various sizes (49mm to 58mm diameter). Standard (spouted) portafilters have one or two spouts; bottomless (naked) portafilters expose the basket bottom, allowing visual diagnosis of extraction quality.

A manual drip brewing method where the brewer controls the flow of water over ground coffee. Popular devices: Hario V60 (cone, single large hole), Kalita Wave (flat bottom, three holes), Chemex (thick paper filter, hourglass shape), Origami (variable filter compatibility). Each produces a different cup due to filter shape, material, and flow dynamics.

In espresso: wetting the coffee puck with low-pressure water before full extraction pressure is applied. Saturates the puck uniformly, reducing channeling. Duration: 2 to 10 seconds on most machines. Some machines (like the La Marzocco Strada) allow programmable pre-infusion pressure profiles.

Varying the water pressure during an espresso extraction, either through manual lever control or programmable electronic systems. Allows the barista to start with low pressure (pre-infusion), ramp to full pressure, and optionally reduce pressure near the end. Machines like the La Marzocco Strada, Decent, and Slayer are designed for pressure profiling.

The methods used to transform harvested coffee cherries into green (exportable) beans. Primary methods: washed (wet), natural (dry), honey (pulped natural), and wet-hulled (giling basah). Processing has as much impact on cup flavor as variety and terroir.

The complete record of temperature over time during a coffee roast. Includes bean temperature curve, RoR curve, and often environmental temperature. Profiles are recorded by software (Cropster, Artisan, RoastPath) and used for consistency, analysis, and replication.

The compressed disc of coffee grounds in an espresso portafilter after tamping and before or after extraction. Puck preparation (distribution, tamping, WDT) is critical to even extraction. A "soupy" or "muddy" spent puck can indicate channeling or incorrect dose.

The fruit flesh (mesocarp) of the coffee cherry surrounding the mucilage and seed. Sweet and slightly tangy when ripe. Removed mechanically during depulping in washed and honey processing. Left intact during natural processing.

A processing method where the cherry skin is removed but the mucilage is left intact during drying. Originated in Brazil. Similar to honey process but the term is more commonly used in Brazilian production. Produces medium body, moderate sweetness, and round acidity.

A licensed coffee quality evaluator certified by the Coffee Quality Institute (CQI). Q-Graders pass a rigorous series of exams covering cupping, olfactory skills, green and roasted coffee identification, organic acid identification, and triangulation (detecting odd samples). Certification must be renewed every three years.

The total score assigned to a coffee by a Q-Grader using the SCA cupping protocol. Scale: 0 to 100. Below 80: commodity grade. 80 to 84.99: specialty grade. 85 to 89.99: excellent specialty. 90+: outstanding. Scores are the sum of ten individual attribute scores plus a final "overall" score.

A bean that remains pale after roasting due to insufficient sugar content (from unripe cherries). Cannot undergo the Maillard reaction normally. Tastes papery, peanutty, grassy. A green coffee defect that manifests during roasting. Must be removed by hand or color sorter after roasting.

Rapidly cooling roasted coffee immediately after it exits the roaster, usually with a combination of airflow and (sometimes) a fine water mist. Purpose: stop the roast precisely and prevent continued thermal development. Water quenching is controversial in specialty roasting; air cooling is preferred.

A sustainability certification (merged with UTZ in 2018) focused on environmental, social, and economic sustainability. Covers biodiversity, natural resource conservation, and worker welfare. Less focused on minimum price (unlike Fair Trade) and more on farming practices.

An elevated drying structure with mesh netting, allowing air to circulate above and below the coffee. Also called African beds (originated in East Africa). Promotes more even drying and better airflow than concrete patios. Standard in specialty processing in Ethiopia, Kenya, and Rwanda.

An optical instrument that measures the refractive index of a liquid, from which Total Dissolved Solids (TDS) can be calculated. In coffee, TDS and brew ratio are used to calculate extraction yield. The VST CoffeeTool and DiFluid are common digital coffee refractometers. The tool that brought quantitative measurement to specialty coffee.

The period after roasting during which CO2 degasses and flavors develop. Most filter coffee tastes best 7 to 14 days after roasting. Espresso often benefits from 10 to 30 days of rest. Excessively fresh coffee (1 to 3 days post-roast) can taste sharp, gassy, and underdeveloped.

The perception of aroma through the back of the throat and nasal passages while tasting. Most of what we call "flavor" is actually retro-nasal aroma. This is why coffee tastes different from how it smells: orthonasal (sniffing) and retro-nasal (tasting) activate different olfactory receptor patterns.

A severe defect flavor resembling iodine, medicinal, or phenolic compounds. Named after Rio de Janeiro, where such coffees were historically common. Caused by specific bacterial contamination of the cherry. A primary defect: one Rio-flavored bean can taint an entire cup.

Italian for "restricted." An espresso pulled with less water, typically 1:1 to 1:1.5 ratio. Produces a smaller, more concentrated, sweeter shot. Only the earliest-extracting compounds (acids and sugars) are captured. Less bitter than a standard espresso but potentially unbalanced if under-extracted.

Common name for Coffea canephora. Grown at lower altitudes (0 to 800m) in hotter, more humid climates. Higher caffeine (1.7 to 4%), more body, less acidity, more bitterness than Arabica. Major producers: Vietnam (largest), Brazil, Indonesia, India, Uganda. Used in espresso blends for crema and body, in instant coffee, and increasingly as specialty "fine Robusta."

The first derivative of bean temperature with respect to time, typically in degrees C per minute. The most important diagnostic tool in roast profiling. A healthy profile shows steadily declining RoR. A rising RoR late in the roast signals potential scorching. A crashed RoR signals baking. Monitored in real time on roasting software.

A Kenyan cultivar developed at the Coffee Research Station in Ruiru. Compact plant, resistant to coffee berry disease and leaf rust. Named for the station location. Cup quality has been historically lower than SL-28/SL-34, but newer selections are improving.

A small-batch roast (typically 50 to 150g) used to evaluate green coffee before production roasting. Roasted to a standard light-to-medium profile following SCA protocol (Agtron 55 to 65 on ground). The sample is then cupped to determine quality, defects, and potential.

A cross between Villa Sarchi (a Costa Rican Bourbon mutation) and Timor Hybrid. Disease-resistant. Includes Marsellesa, Obata, and other modern cultivars. Cup quality varies but improving with each breeding generation.

Specialty Coffee Association. Formed in 2017 by the merger of the SCAA (America) and SCAE (Europe). Sets industry standards for cupping, brewing, green grading, roasting, and barista skills. Publishes the cupping protocol, the flavor wheel, and certification programs for coffee professionals.

A roast defect where the bean surface chars from excessive conductive heat (contact with the hot drum wall). Visible as dark marks or burn spots on the flat faces of the bean. Tastes smoky, burnt, ashy. Caused by charge temperature too high or drum speed too slow.

A measurement of green coffee bean size using screens with round holes of specific diameters, measured in 64ths of an inch. Screen 15 = 15/64 inch (5.95mm). Screen 17 to 18 is common for premium Arabica. Larger beans are often (but not always) correlated with higher quality. Used in grading systems: Colombia Supremo is screen 17+, Excelso is screen 14 to 16.5.

Coffee grown under a canopy of taller trees. The traditional method. Shade slows cherry maturation, producing denser, more complex beans. Supports biodiversity (bird habitat, insect diversity). Contrasted with sun-grown (full-sun monoculture), which produces higher yield but lower complexity and requires more agrochemical input.

The thin, papery spermoderm directly surrounding the coffee bean, inside the parchment. Most is removed during hulling and roasting (becoming chaff). Residual silver skin in the center crease of the bean is normal.

See Silver Skin.

Coffee from one defined geographic source: a country, region, farm, or lot. The term is intentionally vague. "Single-origin Ethiopia" and "single-origin Hacienda La Esmeralda Lot A3" are both technically single origin. In specialty coffee, single origin usually implies farm or cooperative level traceability.

Grinding only the exact dose needed for one brew, rather than filling the grinder hopper with beans. Preserves freshness and allows switching between coffees. Requires a low-retention grinder. Standard practice in specialty home brewing.

A vacuum brewing device using two chambers connected by a tube. Water in the lower chamber is heated, vapor pressure pushes it to the upper chamber where it mixes with coffee. When heat is removed, a vacuum pulls the brewed coffee back down through a filter. Invented in the 1830s. Perfected by Japanese kissaten (coffee houses). Theatrical, precise, produces an exceptionally clean cup.

A Kenyan varietal selected by Scott Agricultural Laboratories in the 1930s from a drought-resistant Tanganyika (Tanzanian) population. Produces exceptional cup quality: intense acidity, blackcurrant, citrus, complex fruit. Susceptible to coffee berry disease and leaf rust. One of the most prized specialty coffee varietals in the world.

A Kenyan varietal selected by Scott Laboratories from a French Mission Bourbon population. Similar quality to SL-28 but more adapted to high rainfall areas. The two SL varietals together define the flavor profile of premium Kenyan coffee.

The act of forcefully aspirating coffee from a cupping spoon. The slurp aerates the coffee across the entire palate, allowing simultaneous assessment of all flavor attributes. The louder the slurp, the better the aeration. Professional cupping rooms are noisy.

The portion of roasted coffee that can be dissolved in water. Approximately 28 to 30% of roasted coffee by weight is soluble. Of that, the target extraction yield is 18 to 22%. The remaining solubles extract with increasingly bitter and astringent character.

Coffee scoring 80 or above on the SCA 100-point cupping scale, with zero primary defects and no more than five secondary defects per 350g green sample. The term was coined by Erna Knutsen in 1974. Specialty-grade coffee represents approximately 20 to 25% of global Arabica production.

The current market price for immediate delivery of coffee. Contrasted with futures prices (delivery at a future date). Spot prices reflect real-time supply and demand conditions.

A Central American grading term for coffee grown above 1,370 meters (4,500 feet). Hard Bean (HB) is grown at 1,200 to 1,370m. The altitude classification implies density and quality. Used in Guatemala, Costa Rica, and Honduras.

An alternative altitude grading term used in some Central American countries, particularly El Salvador and Honduras. Equivalent to Strictly Hard Bean. Grown above 1,200m.

A state of matter achieved when a substance is heated and pressurized beyond its critical point. Supercritical CO2 (31.1 C, 73.8 atm) has liquid-like density but gas-like diffusivity, making it an excellent selective solvent for caffeine extraction.

A positive attribute scored on the SCA cupping form. Perceived sweetness in coffee comes from caramelized sugars, certain organic acids, and the absence of defects. A truly sweet cup is the sign of ripe cherries, careful processing, and proper roasting. Not sugar-sweet, but the full, round, pleasant sensation of inherent sweetness.

A chemical-solvent-free decaffeination method using water, temperature, and activated charcoal filters. Green beans are soaked in Green Coffee Extract (GCE), which is saturated with flavor compounds but free of caffeine. Osmotic pressure drives caffeine out of the beans while flavor compounds remain. Removes 99.9% of caffeine. Organic-certifiable. Developed in Switzerland, commercialized in Vancouver, BC.

Compressing ground coffee in an espresso portafilter basket using a flat-bottomed tamper. Purpose: create a level, uniformly dense coffee bed for even water flow. Standard pressure: 15 to 30 lbs. Consistency matters more than absolute pressure. Self-leveling tampers (Pullman, Decent) reduce the skill requirement.

A tool used to compress ground coffee in an espresso portafilter. Flat-bottomed, usually aluminum or stainless steel, sized to match the basket diameter (typically 58mm). Self-leveling tampers (calibrated spring, flat base) are increasingly popular for consistency.

Total Dissolved Solids. The concentration of dissolved coffee compounds in the brewed liquid, expressed as a percentage. Measured with a refractometer. Typical targets: 1.15 to 1.45% for filter coffee, 7 to 12% for espresso. TDS combined with brew ratio gives extraction yield.

The complete natural environment in which coffee is produced: soil, climate, altitude, rainfall, humidity, slope, shade. Borrowed from wine. Terroir explains why the same varietal tastes different when grown in different places. A Bourbon grown in Rwanda tastes fundamentally different from a Bourbon grown in El Salvador, even with identical processing.

A movement in coffee culture that treats coffee as an artisanal food product, like wine or craft beer. Emphasis on origin, processing, light roasting, manual brewing, direct trade, and transparency. Named by Trish Rothgeb in 2002. Contrasted with first wave (commodity) and second wave (espresso-bar culture).

A natural cross between Arabica and Robusta discovered on the island of Timor in the 1920s. Resistant to coffee leaf rust. Parent of Catimor, Sarchimor, Castillo, and many modern disease-resistant cultivars. The single most important genetic resource in coffee breeding for disease resistance.

A roast defect where the pointed ends of the bean darken or char from conductive heat. The tips are thinner and more vulnerable. Caused by excessive charge temperature, slow drum speed, or small batch size. Visible on inspection of roasted beans.

A sensory evaluation test used in Q-Grader certification. Three cups are presented, two identical and one different. The taster must identify the odd cup. Tests palate sensitivity and consistency.

Coffee ground to powder-fine consistency, combined with cold water (and sugar, if desired) in a cezve (small copper pot), heated until foam rises. Poured unfiltered into small cups. The grounds settle at the bottom. UNESCO Intangible Cultural Heritage (2013). The oldest continually practiced brewing method in the world.

The original Arabica cultivar spread from Yemen to the rest of the world. One of two ancestral varietals (with Bourbon). Produces clean, sweet, complex coffee. Low yield and tall plant structure make it commercially challenging. Sub-varietals include Maragogype, Blue Mountain, Kona Typica, and Sumatra Mandheling.

Dissolving too few compounds from the coffee (extraction yield below 18%). Taste: sour, thin, salty, lacking sweetness. Caused by grind too coarse, water too cool, brew time too short, or insufficient agitation. Only the quickly-dissolving acids are captured; the balancing sugars and oils are left behind.

Consistency of flavor across multiple cups of the same coffee. Scored on the SCA cupping form by comparing five cups. Non-uniform cups indicate inconsistent processing or defects. A score of 10 means all five cups taste the same.

A sustainability certification program that merged with Rainforest Alliance in 2018. Focused on sustainable farming practices, social conditions, and environmental management. The combined Rainforest Alliance/UTZ standard is now one of the most widely used certifications in coffee.

A cone-shaped pour-over dripper made by Hario (Japan). Named for the 60-degree angle of the cone. Features spiral ribs inside the cone to separate the filter from the wall, promoting even extraction. Available in ceramic, glass, plastic, metal, and copper. The most popular manual pour-over device worldwide.

A naturally occurring variant of a species. In coffee, Bourbon and Typica are true varietals (natural mutations). The term is often used loosely to include cultivars (bred varieties). Coffee varietals are analogous to grape varietals in wine: they define the genetic potential of the cup.

A medium-dark roast, just at the start of second crack. Some surface oil. Rich, bittersweet, with moderate acidity. Named for the Viennese tradition of adding milk and sugar. A classic European espresso roast level.

A natural Bourbon mutation discovered in Sarchi, Costa Rica. Compact plant, good cup quality. Parent of Sarchimor (crossed with Timor Hybrid).

Also called wet process. Cherries are depulped, fermented (to remove mucilage), washed with clean water, and dried. Produces clean, bright, transparent cups that highlight terroir and varietal character. The standard for most Central American, Colombian, Kenyan, and Ethiopian coffees. Requires significant water resources.

A facility where smallholder farmers deliver cherry for processing. Common in Ethiopia, Rwanda, Burundi, and Kenya, where most producers own too little land to process their own coffee. A single washing station may receive cherry from hundreds of farmers. Station quality varies enormously and directly affects cup quality.

A measure of the available moisture in green coffee (expressed as aw, ranging from 0 to 1). Ideal range: 0.45 to 0.65 aw. Below 0.45, the coffee may taste papery or woody. Above 0.65, mold risk increases. Water activity is a more accurate indicator of storage stability than moisture content alone.

The mineral composition of water used for brewing. Key minerals: calcium (extracts acids and sugars), magnesium (extracts fruity, complex notes), bicarbonate (buffers acidity). SCA recommends 50 to 175 ppm TDS, calcium hardness 1 to 5 grains, pH 6.5 to 7.5. Water is 98% of brewed coffee; its chemistry is not optional.

Weiss Distribution Technique. Using a thin needle or multi-needle tool to stir and redistribute espresso grounds in the portafilter basket before tamping. Breaks up clumps and fills voids, creating a more uniform density. Named after John Weiss, who popularized it on home-barista.com forums. Now standard practice in specialty espresso preparation.

The facility where coffee cherries are received, depulped, fermented, and washed. Also called a washing station or beneficio. The wet mill handles the initial processing steps. The dried parchment coffee then goes to the dry mill for hulling and grading.

See Giling Basah. A processing method where parchment is removed at high moisture content (30 to 50%), then the naked bean is dried to export moisture. Unique to Indonesia. Produces low acidity, heavy body, and earthy, herbal flavors.

In brewing: extraction yield is the percentage of dry coffee mass that dissolves into the water. Calculated as (TDS x brew weight) / dose. Target: 18 to 22% for most methods. In agriculture: the weight of cherry or green coffee produced per hectare per year. Arabica averages 1,500 to 3,000 kg/ha green equivalent.

A woreda (district) in the Gedeo Zone of southern Ethiopia. One of the most famous coffee origins in the world. Produces washed coffees with intense floral, citrus, and tea-like character. Grows at 1,700 to 2,200 masl. Often spelled Yrgacheffe, Yirgachefe, or Yirga Cheffe.

The peak temperature reached by the bean during a roast, measured at the end or drop point. Also called end temperature or drop temperature. Determines the roast level. Typical range: 195 C (light) to 230 C (dark).