The Complete Coffee Glossary: Coffee Industry Overview

A

Acidity — A positive sensory attribute describing bright, lively, sharp flavors in coffee. Not to be confused with pH. High-quality acidity manifests as citric, malic, tartaric, or phosphoric character. Measured on cupping forms as a quality and intensity score. Low-altitude, dark-roasted, and robusta coffees tend toward lower perceived acidity.

Adsorption — The adhesion of molecules to a surface. In coffee, CO2 is adsorbed onto internal cell wall surfaces of roasted beans. Distinct from absorption, which involves penetration into the bulk of a material.

Aeropress — A manual immersion-pressure hybrid brewer invented by Alan Adler in 2005. Uses air pressure from a hand-operated plunger to push water through a bed of coffee and a paper or metal filter. Known for versatility, portability, and the annual Aeropress Championship.

Aftertaste — The lingering flavors and sensations remaining in the mouth after swallowing coffee. Evaluated on SCA cupping forms. A long, pleasant, evolving aftertaste is considered a hallmark of quality. Also called finish.

Ageing (green) — Intentional or unintentional storage of green coffee for extended periods. Past-crop and old-crop coffees develop muted acidity, increased body, and woody or baggy off-flavors if not stored under controlled conditions. Monsooned Malabar is a deliberate aging process.

Agroforestry — An agricultural system integrating trees with crops. In coffee, shade trees provide canopy cover, nitrogen fixation, biodiversity habitat, erosion control, and supplemental income from timber or fruit.

Altitude — Elevation above sea level at which coffee is grown. Higher altitude generally correlates with cooler temperatures, slower cherry maturation, denser beans, and more complex flavor development. Commonly measured in meters above sea level (masl).

anaerobic fermentation — A processing technique where coffee cherries or parchment are fermented in sealed, oxygen-depleted environments (tanks, barrels, sealed bags). Promotes specific microbial activity and can produce intense, distinctive flavor profiles including wine-like, tropical fruit, and cinnamon notes.

Arabica — Coffea arabica, the species responsible for approximately 55 to 60 percent of global coffee production. Self-pollinating tetraploid. Generally higher cup quality, lower caffeine, and more climate-sensitive than robusta. Originated in the highland forests of Ethiopia.

Arabinogalactan — A polysaccharide found in green coffee that contributes to body and mouthfeel in brewed coffee. Partially broken down during roasting.

Astringency — A drying, puckering sensation in the mouth caused by polyphenolic compounds binding to salivary proteins. In coffee, associated with chlorogenic acids and over-extraction. Distinguished from bitterness (a taste) because astringency is a tactile sensation.

Atmos packaging — Packaging technology that actively removes oxygen from sealed bags of roasted coffee, extending shelf life beyond standard one-way valve bags.

Atticaya / Arabusta — Interspecific hybrids between Coffea arabica and Coffea canephora (robusta). Bred for disease resistance and climate tolerance while retaining arabica-like cup quality. Examples include Timor Hybrid derivatives (Catimor, Sarchimor).

Aw (water activity) — A measure of free water available for chemical and microbial activity in green coffee. Expressed on a scale of 0 to 1.00. Target for safe storage is below 0.70 aw. Distinct from moisture content, which measures total water.

B

Bag (coffee bag) — Standard unit of green coffee volume. Size varies by origin: 60 kg in most countries, 69 kg in Brazil, 46 kg in Hawaii. Also refers to the packaging material (GrainPro, jute, hermetic bags) used for transport and storage.

Balance — A cupping term describing the harmonious integration of flavor, acidity, body, and aftertaste. Well-balanced coffee has no single attribute dominating.

Batch roaster — A drum or fluid-bed roaster that roasts a discrete quantity (batch) of coffee at a time, in contrast to continuous roasters. Most specialty roasters use batch systems for greater control.

Beneficio — Spanish term for a wet mill or processing facility where harvested coffee cherries are depulped, fermented, washed, and dried.

Bird Friendly — A shade-grown coffee certification administered by the Smithsonian Migratory Bird Center requiring organic certification, minimum 40 percent canopy cover, at least 10 shade tree species, and 12-meter minimum canopy height.

Bitterness — One of the five basic tastes. In coffee, bitterness comes from caffeine (10 to 15 percent of perceived bitterness), chlorogenic acid lactones, and Maillard reaction products. Some bitterness is expected and desirable; excessive bitterness indicates over-extraction or roast defects.

Blend — A mixture of coffees from different origins, farms, or lots, combined to achieve a target flavor profile, consistency, or price point. Contrasted with single-origin offerings.

Bloom — The initial wetting phase of pour-over brewing during which CO2 escapes from freshly ground coffee, causing the bed to swell and bubble. Typically uses 2 to 3 times the coffee weight in water and lasts 30 to 45 seconds. Serves as a freshness indicator and prepares the bed for even extraction.

Body — The tactile weight and texture of coffee in the mouth. Described using terms like light, medium, full, syrupy, creamy, or silky. Influenced by dissolved solids, emulsified oils, and suspended fine particles. Paper filters reduce body by trapping oils; metal filters and immersion methods preserve it.

Bourbon — A natural mutation of Typica that developed on Reunion Island (formerly Bourbon). One of the most important heritage arabica varieties. Known for sweetness, complexity, and relatively low yield. Parent of many modern varieties including Caturra, Catuai, SL28, SL34, and Pacas.

Brewing ratio — The ratio of ground coffee to water, typically expressed as grams of coffee per grams (or milliliters) of water. Common pour-over ratios range from 1:15 to 1:17. Espresso ratios range from 1:1.5 to 1:2.5.

burr grinder — A grinder that crushes beans between two abrasive surfaces (burrs). Produces more uniform particle distribution than blade grinders. Available in flat burr and conical burr configurations, each producing different particle size distributions.

C

C-market — The global futures exchange for arabica coffee, trading on the ICE (Intercontinental Exchange) in New York. Contract size is 37,500 pounds. Prices quoted in US cents per pound. The C-price serves as a benchmark for physical coffee transactions.

Cafestol — A diterpene compound found in coffee oils. Raises serum LDL cholesterol when consumed in unfiltered coffee. Removed by paper filtration. Also exhibits potentially beneficial anti-inflammatory properties.

Caffeine — An alkaloid (1,3,7-trimethylxanthine) that acts as a central nervous system stimulant. Arabica contains approximately 1.2 percent caffeine by dry weight; robusta approximately 2.2 percent. Thermally stable through roasting. Highly water-soluble, extracting early in the brew process.

carbonic maceration — A processing technique borrowed from winemaking in which whole coffee cherries are placed in sealed tanks and exposed to carbon dioxide gas. The anaerobic, CO2-rich environment modifies fermentation pathways, producing distinctive flavor profiles. Popularized in specialty coffee by Sasa Sestic.

Cascara — The dried skin and pulp (exocarp and mesocarp) of the coffee cherry, sometimes brewed as a tea-like infusion. Rich in antioxidants. Flavor is fruity, sweet, and slightly tannic, more reminiscent of dried fruit tea than coffee.

Catimor — A hybrid variety derived from crossing Caturra with Timor Hybrid (a natural arabica-robusta cross). Resistant to coffee leaf rust. Cup quality ranges from acceptable to good depending on growing conditions, specific line, and processing.

Caturra — A natural dwarf mutation of Bourbon discovered in Brazil. Higher-yielding than Bourbon due to shorter internodes that allow denser planting. Widely grown across Latin America. Good cup quality but susceptible to coffee leaf rust.

CGA (chlorogenic acid) — A family of phenolic compounds comprising 6 to 9 percent of arabica green beans. Primary source of perceived acidity in coffee. Major antioxidant. Progressively degraded during roasting.

Channeling — Uneven water flow through a coffee bed caused by cracks, fissures, or density variations in the puck or pour-over bed. Results in simultaneous over-extraction (where water concentrates) and under-extraction (where water bypasses). A primary extraction defect in espresso.

Cherry — The fruit of the coffee plant. A drupe containing an outer skin (exocarp), pulp (mesocarp), mucilage, parchment (endocarp), silverskin (spermoderm), and typically two seeds (coffee beans). A small percentage of cherries produce a single round seed called a peaberry.

Clarity — A sensory term describing the distinctness and definition of individual flavors in a cup. Clean, transparent coffees with separable flavor notes are described as having high clarity. Opposite of muddled or muddy.

Clean cup — A cupping criterion referring to the absence of defects, taints, or off-flavors. A clean cup has no distracting negative attributes from first sip through aftertaste.

Cold brew — Coffee brewed with cold or room-temperature water over an extended period (12 to 24 hours). The low temperature extracts less acidity and bitterness, producing a smooth, sweet concentrate. Distinct from flash brew (iced pour-over), which uses hot water brewed directly over ice.

Commodity coffee — Coffee traded as an undifferentiated bulk product at or near C-market prices. Contrasted with specialty coffee, which is differentiated by quality, origin, and traceability.

Cooperative — An organization of smallholder coffee farmers who pool resources for processing, marketing, and negotiation. Cooperatives aggregate individual farmers’ small lots into exportable volumes and distribute premiums to members. Common in Latin America, East Africa, and Southeast Asia.

Crema — The layer of tan-to-brown foam on top of an espresso shot, formed by emulsified oils and pressurized CO2. Fresh coffee produces thicker crema. Crema contains both desirable aromatic compounds and bitter, ashy flavors; some baristas skim it for cleaner taste.

Cupping — A standardized evaluation protocol for assessing coffee quality. Involves coarsely grinding coffee, steeping in hot water, breaking the crust, skimming, and evaluating fragrance, aroma, flavor, aftertaste, acidity, body, balance, uniformity, sweetness, clean cup, and overall impression. The SCA protocol uses a 100-point scale.

CYP1A2 — The gene encoding the liver enzyme (cytochrome P450 1A2) primarily responsible for caffeine metabolism. Variants determine whether an individual is a fast or slow caffeine metabolizer, significantly affecting caffeine sensitivity and health responses.

D

decaffeination — The process of removing caffeine from green coffee beans. Methods include Swiss Water Process (water-based solvent-free), methylene chloride solvent process, ethyl acetate process (sometimes marketed as sugarcane decaf), and supercritical CO2 extraction. All methods remove 97 to 99.9 percent of caffeine.

Defect — A physical or sensory flaw in green or roasted coffee. Physical defects include full black beans, sour beans, insect damage, foreign matter, and broken beans. Sensory defects include ferment, phenol, Rio, potato, and chemical taints. The SCA green grading protocol categorizes defects as Category 1 (full) or Category 2 (partial).

Degassing — The release of CO2 from roasted coffee over time. Approximately 40 to 50 percent of trapped CO2 escapes in the first 24 hours. Degassing rate is influenced by roast level, bean density, grind state, temperature, and packaging.

Density — The mass per unit volume of green or roasted coffee beans. Higher density generally indicates higher altitude, slower maturation, and greater cup quality potential. Measured by displacement or free-fall sorting.

Development — In roasting, the phase after first crack during which Maillard reactions, caramelization, and flavor development intensify. Underdeveloped roasts taste grassy, grainy, or bready. Overdeveloped roasts taste ashy, smoky, or carbonic.

Differential — The premium or discount applied to the C-market price when trading physical coffee. Reflects origin, quality, availability, and logistics. High-demand specialty origins carry positive differentials; lower-demand or commodity-grade coffees may carry negative differentials.

Direct trade — A sourcing model where roasters purchase coffee directly from producers or exporters, bypassing traditional commodity trading channels. No formal certification exists; the term is self-defined by each company. Implies shorter supply chains, higher farmgate prices, and relationship-based sourcing.

Dose — The weight of dry ground coffee used for a brewing recipe. Espresso dose is typically 14 to 22 grams. Pour-over dose varies by serving size, commonly 15 to 30 grams.

Dry mill — A processing facility where dried parchment coffee is hulled (parchment removed), graded by screen size and density, sorted for defects (by hand, machine, or optical sorter), and bagged for export. Distinct from the wet mill, which handles fresh cherry.

DTR (Development Time Ratio) — The percentage of total roast time that occurs after first crack. Used as a roast profile metric. Common DTR values range from 15 to 25 percent for specialty filter roasts. Lower DTR tends toward brighter, more acidic profiles; higher DTR toward more developed, sweeter, rounder profiles.

E

Espresso — A concentrated coffee beverage produced by forcing hot water (typically 90 to 96 degrees Celsius) through finely ground, compacted coffee at approximately 9 bars of pressure. Typically 25 to 35 milliliters extracted in 25 to 35 seconds from 14 to 22 grams of coffee. Characterized by concentrated flavor, full body, and crema.

Ethyl acetate (EA) process — A decaffeination method using ethyl acetate as a solvent. Since EA occurs naturally in fruits and sugarcane, this process is sometimes marketed as natural or sugarcane decaf. Produces a generally clean cup with some fruity character but can leave a slight solvent note if not properly managed.

Extraction — The process of dissolving soluble compounds from ground coffee into water. Measured as extraction yield (EY), the percentage of dry coffee mass that dissolves into the brew. Optimal EY for most methods is 18 to 22 percent. Under-extraction produces sour, thin, salty cups. Over-extraction produces bitter, astringent, hollow cups.

EY (Extraction Yield) — The percentage of dry coffee mass dissolved into the brew. Calculated as (TDS x brew weight) / dose. Industry target is 18 to 22 percent for most brewing methods. refractometer-measured TDS is used to calculate EY.

F

Fairtrade — A certification and labeling system guaranteeing minimum farmgate prices and social premiums for coffee produced by certified cooperatives. The Fairtrade minimum price sets a floor below which buyers cannot purchase. Additional premiums fund community development.

Fermentation — A metabolic process in which microorganisms (bacteria, yeasts, fungi) break down organic compounds. In coffee processing, fermentation degrades the mucilage layer surrounding parchment coffee. Fermentation type (aerobic, anaerobic, controlled-temperature, extended) significantly influences final cup character.

Filter — A barrier that separates brewed coffee from spent grounds. Paper filters (bleached or natural) produce clean, lighter-bodied cups by trapping oils and fine particles. Metal filters allow oils and fines to pass, producing fuller-bodied, cloudier cups. Cloth filters fall between the two.

First crack — An audible popping sound during roasting caused by moisture inside the bean converting to steam and expanding, fracturing the cell structure. Occurs around 196 to 205 degrees Celsius. Marks the boundary between light and medium roast development. Most specialty coffee is roasted to a point during or just beyond first crack.

Flat white — An espresso-based milk drink originating in Australia/New Zealand. Typically a double ristretto with steamed microfoam milk, producing a velvety texture with a higher coffee-to-milk ratio than a latte.

Flavor — In cupping, a combined assessment of taste (sweet, sour, salty, bitter, umami) and retronasal aroma perceived while the coffee is in the mouth. Scored on the SCA cupping form for both quality and intensity.

FOB (Free on Board) — The price of green coffee at the port of origin, after processing, milling, grading, and local transport but before ocean freight and import costs. The standard reference point for discussing producer-level pricing in the supply chain.

Fragrance/Aroma — In SCA cupping protocol, fragrance refers to the smell of dry ground coffee; aroma refers to the smell of wet coffee after hot water is added. Scored together as a single attribute on the cupping form.

Freeze-drying — A method of producing instant coffee by freezing brewed coffee extract and then sublimating the ice under vacuum. Preserves more volatile aromatics than spray-drying. Also refers to the practice of freezing roasted beans for long-term preservation of freshness.

French press — An immersion brewer consisting of a glass or metal carafe and a metal mesh plunger filter. Coffee steeps in hot water for 3 to 5 minutes, then the plunger separates grounds from liquid. Produces full-bodied, oily coffee because the metal filter allows lipids and fine particles to pass.

Fructose — A reducing sugar present in small quantities in green coffee. Participates in Maillard reactions during roasting.

G

Gesha/Geisha — A variety of Coffea arabica originating from the Gesha region of Ethiopia, famously cultivated at Hacienda La Esmeralda in Panama. Known for extraordinary floral, jasmine, bergamot, and tropical fruit character. Commands some of the highest prices in specialty coffee history at auction.

GH (General Hardness) — A measure of the calcium and magnesium ion concentration in water, typically expressed in parts per million (ppm) as CaCO3. Relevant to brewing water chemistry. SCA water standard recommends 50 to 175 ppm GH. Affects extraction rate and flavor clarity.

Grading — The classification of green coffee by physical attributes (screen size, defect count, density, moisture, color) and/or sensory evaluation (cupping score). Systems vary by country: Kenya uses AA/AB/PB screen grades; Ethiopia uses Grade 1-5 defect counts; Colombia uses Supremo/Excelso screen sizes; Guatemala uses altitude-based SHB/HB designations.

Green coffee — Unroasted coffee beans after processing and milling. Green beans are stable for months to over a year under proper storage conditions (cool, dry, protected from light and moisture). The raw material from which roasters create their products.

H

honey process — A coffee processing method in which the cherry skin is removed but some or all of the mucilage is left on the parchment during drying. Classified by the amount of mucilage retained: white honey (least), yellow honey, red honey, and black honey (most). Produces cup profiles between washed (clean, bright) and natural (fruity, heavy-bodied).

Hulling — The mechanical removal of parchment (endocarp) from dried coffee beans at the dry mill. For natural-processed coffees, hulling also removes the dried cherry skin and fruit material.

I

ICE (Intercontinental Exchange) — The commodities exchange where the Coffee C futures contract trades. Formerly the New York Board of Trade. Sets the global benchmark price for arabica coffee.

Immersion brewing — A method where ground coffee steeps in water for a set time before filtration. Examples include French press, AeroPress (partial immersion), Clever Dripper (hybrid immersion-percolation), cupping, and cold brew. Contrasted with percolation (pour-over, drip), where water passes through the coffee bed.

IWCA (International Women’s Coffee Alliance) — A nonprofit organization working to empower women across the coffee value chain through country-level chapters, leadership training, business skills development, and networking.

K

Kahweol — A diterpene compound found alongside cafestol in coffee oils. Similar cholesterol-raising effect in unfiltered coffee. Shows anti-inflammatory and potentially anti-carcinogenic properties in laboratory studies.

KH (Carbonate Hardness) — A measure of bicarbonate and carbonate ions in water, also called alkalinity or buffer capacity. Expressed in ppm as CaCO3. Affects coffee extraction by neutralizing acids, influencing perceived acidity. SCA standard recommends approximately 40 ppm KH. High KH mutes brightness; low KH produces harsh, sharp acidity.

L

lactic fermentation — A fermentation process dominated by lactic acid-producing bacteria (Lactobacillus and related genera). In controlled coffee processing, lactic fermentation can produce creamy, yogurt-like, and tangy cup profiles.

Landrace — A locally adapted, genetically diverse population of a crop species developed through natural selection and traditional farming over many generations. Ethiopian coffee landraces represent the most genetically diverse arabica populations and are critical genetic resources for breeding programs.

Light roast — Coffee roasted to first crack or slightly beyond. Retains more origin character, acidity, and chlorogenic acids. Lower caramelization and Maillard product development compared to darker roasts. Preferred in modern specialty coffee for highlighting terroir and varietal character.

Living income — The income required for a farming household to afford a decent standard of living, including food, housing, education, healthcare, and a modest buffer for savings. Living income reference prices for coffee are calculated by organizations including Fairtrade International and the Living Income Community of Practice.

Lot — A discrete, traceable quantity of coffee, typically from a single farm, cooperative, or processing batch. Microlots are small volumes (often under 20 bags) selected for exceptional quality. Nano-lots are even smaller, sometimes a single day’s picking or a single variety from a single plot.

M

Maillard reaction — A complex cascade of non-enzymatic browning reactions between reducing sugars and amino acids that occurs during roasting above approximately 150 degrees Celsius. Produces hundreds of flavor compounds including pyrazines, furans, thiols, and melanoidins. The primary driver of roast flavor development.

Masl — Meters above sea level. Standard unit for describing coffee growing altitude.

Melanoidins — High-molecular-weight brown polymers formed in the late stages of Maillard reactions. Comprise up to 25 percent of roasted coffee dry weight. Contribute color, body, antioxidant activity, and may function as prebiotics in the gut.

Microlot — A small, carefully selected lot of coffee, typically from a specific section of a farm, a single variety, or a specific day’s harvest. Microlots are curated for exceptional cup quality and traceability. Often sold at premium prices through specialty channels.

Moisture content — The percentage of water in green coffee beans by weight. Target range is 10 to 12 percent for safe storage and optimal roasting. Measured with electronic moisture meters or laboratory oven drying. Below 10 percent, beans become brittle; above 12.5 percent, risk of mold and microbial growth increases.

Monsooned Malabar — Indian coffee intentionally exposed to monsoon winds and humidity over several months, causing beans to swell, pale, and develop low acidity, heavy body, and distinctive musty-earthy character. A deliberate aging and climate-exposure process originating from the colonial-era observation that long sea voyages altered coffee character.

Mucilage — The sticky, sugar-rich layer surrounding the parchment of a coffee cherry, between the pulp and the parchment. Composed primarily of pectins, sugars, and organic acids. Mucilage removal (through fermentation, mechanical washing, or drying on the bean) is a critical processing variable that affects cup character.

N

natural process — A coffee processing method in which the entire cherry is dried intact, with the fruit remaining on the seed throughout drying. Produces heavier body, lower acidity, and intense fruit character (ranging from blueberry and strawberry to wine and tropical fruit). Also called dry process.

Niche zero — A single-dose flat burr grinder popular in home specialty coffee. Exemplifies the trend toward retention-free, single-dose grinders designed for espresso and filter.

O

Origin — The country, region, farm, or estate where coffee was grown. Single-origin coffees are marketed with origin specificity. Origin character is influenced by terroir (climate, soil, altitude), variety, processing, and post-harvest handling.

P

Parchment — The papery endocarp layer surrounding the coffee seed inside the cherry. Parchment is removed during dry milling (hulling). Coffee in parchment (pergamino in Spanish) is a common storage state between wet milling and export preparation.

Peaberry — A single, round seed that develops when only one ovule is fertilized inside the coffee cherry, instead of the usual two flat-sided seeds. Peaberries are sorted and sold separately in some origins, notably Kenya (PB grade) and Tanzania. Some drinkers believe peaberries produce sweeter, more concentrated cups due to the single seed receiving all the cherry’s nutrients.

Percolation — A brewing method where water flows through a bed of ground coffee by gravity or pressure. Includes pour-over (V60, Chemex, Kalita Wave), drip machines, and espresso. Contrasted with immersion, where coffee steeps in water.

pH — A measure of hydrogen ion concentration indicating acidity or alkalinity on a logarithmic scale of 0 to 14. Brewed coffee typically ranges from pH 4.85 to 5.10. Lower pH indicates more acidic. Not a reliable predictor of perceived acidity, which depends on the specific acid composition and buffering capacity.

Polishing — An optional dry mill process that removes the silverskin (chaff) from green coffee beans by friction. Polished beans have a cleaner appearance but the process does not meaningfully affect cup quality.

Portafilter — The handled filter basket holder used in espresso machines. Contains a metal filter basket into which ground coffee is dosed, distributed, and tamped before being locked into the group head for extraction.

PSD (Particle Size Distribution) — The statistical distribution of ground coffee particle sizes produced by a grinder. Measured by laser diffraction or sieve analysis. Bimodal (two-peaked) distributions are common with burr grinders, with fine and coarse peaks. Narrower distributions generally produce more even extraction; broader distributions can produce simultaneous over- and under-extraction.

Puck — The compressed disc of spent coffee grounds left in an espresso portafilter after extraction. A well-extracted puck is firm and cohesive. A soupy or muddy puck may indicate channeling, incorrect dose, or inappropriate grind size.

Pulped natural — A processing method in which the cherry skin is mechanically removed but mucilage is left largely intact and dried on the parchment without fermentation. Similar to honey process. Common in Brazil, where it is called cereja descascada (peeled cherry).

Q

Q Grader — A licensed coffee professional certified by the Coffee Quality Institute (CQI) through a rigorous multi-day examination covering sensory calibration, olfactory acuity, organic acid identification, green grading, roast identification, and cupping protocol. Q Graders are qualified to score coffee using the CQI/SCA cupping form.

Quaker — An unripe or underdeveloped coffee bean that fails to brown properly during roasting, remaining pale yellow or tan. Quakers produce papery, cereal-like, or peanut-like off-flavors. Classified as a Category 2 defect in SCA green grading.

R

RDT (Ross Droplet Technique) — The practice of spraying a fine mist of water onto whole beans immediately before grinding to reduce static electricity. Reduces chaff retention in the grinder, minimizes mess, and may improve particle distribution uniformity. Named after David Ross, who popularized the technique.

Refractometer — An optical instrument that measures the refractive index of a liquid, used in coffee to determine Total Dissolved Solids (TDS). Digital refractometers calibrated for coffee (such as the VST or DiFluid models) allow precise extraction yield calculation.

Resting — The period between roasting and brewing during which CO2 is released (degassing) and flavor compounds stabilize. Optimal rest periods vary by method: 5 to 10 days for pour-over, 7 to 21 days for espresso. Also called off-gassing or maturing.

Ristretto — An espresso extraction using the same dose but less water (shorter pull), producing a more concentrated, less bitter, and less extracted shot. Typical ristretto ratio is 1:1 to 1:1.5 (dose to yield).

Robusta — Coffea canephora, the second most produced coffee species (approximately 40 to 45 percent of global production). Higher caffeine, lower acidity, more bitter, and more disease-resistant than arabica. Historically associated with low quality but increasingly recognized in fine robusta and specialty robusta segments.

RoR (Rate of Rise) — The speed at which bean temperature increases during roasting, measured in degrees per unit time (typically degrees Celsius per minute or per 30 seconds). Monitoring RoR allows roasters to control the rate and shape of heat application. A declining RoR curve is considered standard for most specialty roast profiles. Stalls or crashes in RoR can indicate baked or scorched flavors.

Roast profile — The time-temperature curve of a coffee roast, including charge temperature, turning point, RoR progression, first crack timing, development time, and drop temperature. Documented using data-logging software (Cropster, Artisan, Roast Path) to ensure reproducibility.

S

SCA (Specialty Coffee Association) — The global trade organization for specialty coffee, formed in 2017 from the merger of the SCAA (Specialty Coffee Association of America) and SCAE (Specialty Coffee Association of Europe). Sets standards for green grading, cupping protocols, water quality, brewing parameters, and barista education.

Screen size — A physical grading measurement based on the diameter of holes in a metal screen through which beans are sorted. Screens are numbered in sixty-fourths of an inch. Screen 18 = 18/64 inch (7.14 mm). Larger screen sizes generally (but not always) correlate with higher quality.

Second crack — A second audible cracking sound during roasting, more rapid and quieter than first crack. Occurs around 224 to 230 degrees Celsius. Marks the onset of dark roast territory. Cell structure begins breaking down, oils migrate to the bean surface, and carbonization increases. Most specialty coffee is dropped before or at the very onset of second crack.

SHB (Strictly Hard Bean) — An altitude-based grading designation used in Guatemala, Costa Rica, and other Central American countries. SHB indicates coffee grown above approximately 1,350 meters (exact threshold varies by country). Hard bean refers to the increased density of beans grown at higher, cooler altitudes.

Silverskin — The thin, papery spermoderm layer adhering directly to the green coffee seed inside the parchment. Most silverskin separates as chaff during roasting and is ejected from the roaster.

Single dose — The practice of weighing and loading only enough beans for one brew session into a grinder, rather than filling a hopper. Eliminates retention (stale grounds left in the grinder) and enables switching between coffees easily.

Single origin — Coffee sourced from one country, region, cooperative, farm, or lot. Marketed to highlight the specific character imparted by terroir, variety, and processing. Contrasted with blends.

Slurry temperature — The temperature of the water-coffee mixture during brewing. Distinct from kettle temperature or water temperature at contact. Slurry temperature is lower than incoming water temperature due to heat absorption by the coffee grounds and brewer.

Specialty coffee — Coffee that scores 80 points or above on the SCA 100-point cupping scale and passes green grading requirements. More broadly, the segment of the coffee industry focused on quality, traceability, and transparency from farm to cup.

Strecker degradation — A chemical reaction within the Maillard cascade in which amino acids react with dicarbonyl compounds to produce aldehydes, CO2, and aminoketones. Strecker aldehydes are potent aroma compounds in roasted coffee.

Sucrose — A disaccharide (table sugar) comprising 6 to 9 percent of arabica green beans. Almost completely destroyed during roasting, serving as a primary precursor for caramelization products and Maillard reaction substrates.

Swiss Water Process — A decaffeination method using water saturated with coffee solubles (except caffeine) to selectively extract caffeine without removing flavor compounds. Chemical-solvent-free. The most common decaf process in specialty coffee.

T

Tamping — The act of compressing ground coffee into the portafilter basket before espresso extraction. Creates a level, uniform puck that promotes even water distribution. Standard tamping pressure is approximately 15 to 20 kilograms of force, though level distribution is more important than exact pressure.

TDS (Total Dissolved Solids) — The concentration of dissolved coffee compounds in brewed coffee, expressed as a percentage. Measured with a refractometer. Filter coffee target: 1.15 to 1.35 percent. Espresso target: 8 to 12 percent. Used to calculate extraction yield.

Terroir — The complete set of environmental factors (soil, climate, altitude, latitude, rainfall, microorganisms) that influence the character of a coffee grown in a specific place. Borrowed from wine terminology.

Third wave — A movement in coffee culture emphasizing high-quality sourcing, transparent trade practices, artisan roasting, and manual brewing. Generally dated from the late 1990s to early 2000s, with companies like Intelligentsia, Counter Culture, and Stumptown as early exemplars.

Tipping — A roast defect where the thin edges or tips of coffee beans are scorched by excessive contact heat early in the roast, appearing as dark spots. Indicates too-high charge temperature or too-aggressive early heat application.

Trigonelline — An alkaloid present at approximately 1 percent in arabica. Thermally decomposes during roasting to yield nicotinic acid (niacin/vitamin B3) and pyridines that contribute to coffee aroma.

Typica — The original cultivated variety of Coffea arabica, from which most other arabica varieties are derived or descended. Low-yielding, tall, and susceptible to disease, but prized for clean, sweet cup quality. The genetic base of varieties including Bourbon, Maragogipe, Blue Mountain, Kona, and many others.

U

Uniformity — A cupping criterion assessing consistency across multiple cups of the same coffee. Defects in one cup but not others reduce the uniformity score. Perfect uniformity earns 10 points on the SCA cupping form.

V

V60 — A conical pour-over dripper designed by Hario, featuring spiral ribs and a large single hole at the bottom. Named for its 60-degree cone angle. One of the most widely used specialty pour-over devices. The open design provides high flow rate and significant brewer control over extraction.

Varietal — Loosely used in coffee to describe a cultivated variety (cultivar) of Coffea arabica. Common varietals include Typica, Bourbon, Caturra, Catuai, SL28, SL34, Gesha, Pacamara, and Castillo. Strictly, varietal refers to a wine made from a single grape variety; the correct botanical term for coffee is variety or cultivar.

W

washed process — A coffee processing method in which the cherry skin and pulp are mechanically removed, mucilage is degraded through fermentation and/or mechanical washing, and the clean parchment coffee is dried. Produces cleaner, brighter cups with more pronounced acidity compared to natural or honey processes.

Water activity (aw) — See Aw.

WDT (Weiss Distribution Technique) — A method of distributing ground coffee in an espresso portafilter using thin needles or acupuncture pins to break up clumps and create a uniform density before tamping. Reduces channeling and improves extraction consistency. Named after John Weiss, who developed the technique.

Wet mill — A processing facility at or near the farm where freshly harvested coffee cherries are depulped, fermented, washed, and initially dried. Also called a washing station (particularly in East Africa) or beneficio (Latin America). The wet mill stage is where the majority of processing-related flavor development occurs.

Y

Yield — In brewing, refers to extraction yield (EY): the percentage of coffee mass dissolved into the brew. In agriculture, refers to the volume of cherry or green coffee produced per plant or per hectare.

Abbreviations Quick Reference