Glossary of Coffee Terms

A working brewer's A-to-Z. Each entry is a short, plain-language definition; where a term has its own full note, the term links to it. For pronunciation-and-flavor vocabulary used at the cupping table, pair this with Describing Coffee and the The Coffee Flavor Wheel.

#A

Acidity: the bright, tangy, often fruity quality of a coffee; a desirable trait in filter brewing, not a defect. → Acidity in Coffee Agitation: physical disturbance of the coffee bed by pouring, stirring, or swirling, which speeds extraction and evens it out. → Agitation and Turbulence Alkalinity (KH): water's capacity to buffer (neutralize) acids; high alkalinity dulls perceived acidity. → Water Hardness and Alkalinity Arabica: the premium coffee species behind nearly all specialty coffee. → The Coffee Plant Astringency: a drying, mouth-puckering sensation, usually a sign of over-extraction or excess fines.

#B

Blade grinder: a grinder that chops beans with a spinning blade, producing uneven particles; avoid for pour over. → Burr Grinders vs Blade Grinders Bloom: the initial wetting of the grounds that releases trapped CO₂ before the main pour. → The Bloom Body: the weight or texture of the coffee in the mouth, from tea-like to syrupy. → Sweetness and Body Boulders: the largest particles in a grind, which under-extract relative to the rest. → Fines and Boulders Burr grinder: a grinder that crushes beans between two abrasive surfaces for a uniform grind. → Burr Grinders vs Blade Grinders Bypass: water that slips down the filter walls without passing through the coffee bed. → Bypass and Channeling

#C

Channeling: water carving a fast path through the bed, causing uneven extraction. → Channeling and Uneven Extraction Conical dripper: a V-shaped, single-hole dripper such as the Hario V60. → Conical vs Flat Bottom Drippers Contact time: the total time water is in contact with the coffee. → Brew Time and Total Contact Time Cupping: the standardized protocol for tasting and scoring coffee. → Cupping

#D

Degassing: the slow release of CO₂ from roasted beans as they age. → Coffee Freshness and Degassing Dialing in: adjusting variables (usually grind) to optimize a given coffee. → Dialing In Grind Size Dose: the mass of dry coffee used, in grams. Drawdown: the final phase as the last water drains through the bed. → The Drawdown

#E

Extraction: the dissolving of soluble compounds out of the grounds and into the brew. → The Science of Extraction Extraction yield (EY): the percentage of the dry coffee mass dissolved into the cup; ~18–22% is the classic target. → Extraction Yield and Strength

#F

Fines: the smallest particles in a grind; they extract fast and can clog the filter. → Fines and Boulders Flat-bottom dripper: a wave or basket dripper with a flat bed, such as the Kalita Wave. → Conical vs Flat Bottom Drippers Flow rate: how quickly water drains through dripper and bed.

#G–H

General hardness (GH): the dissolved calcium and magnesium in water, key to extraction. → Water Hardness and Alkalinity Gooseneck kettle: a kettle with a swan-neck spout for precise, slow pouring. → Gooseneck Kettles Grind size: the coarseness of the ground coffee, the master variable for flow and extraction. → Grind Size for Pour Over

#I–N

Immersion: brewing with the coffee fully steeped in water, as in a French Press. Percolation: brewing with fresh water continuously passing through the bed, as in pour over. Pulse pouring: adding water in discrete bursts rather than one continuous stream. → Pulse vs Continuous Pouring

#R

Ratio: the proportion of water to coffee, e.g. 1:16. → The Brew Ratio Refractometer: a device that reads TDS to calculate extraction. → Refractometers and Measuring Extraction Robusta: the hardier, more bitter coffee species. → The Coffee Plant Roast level: how far beans were roasted, from light to dark. → Roast Levels for Pour Over

#S–T

Slurry: the mix of water and grounds during brewing. Solubility: how readily a compound dissolves; it changes through the brew. → Solubility and What Dissolves Strength: the concentration of dissolved solids, perceived as intensity. → Extraction Yield and Strength TDS (total dissolved solids): the concentration of dissolved coffee in the cup, used to compute extraction. → Total Dissolved Solids (TDS) Terroir: the environmental signature a growing region imparts. → Coffee Growing Regions and Terroir Third wave: the movement treating coffee as an artisanal, origin-driven product. → First, Second, and Third Wave Coffee Turbulence: agitation within the slurry that mixes and evens extraction. → Agitation and Turbulence

#U–W

Under-extraction: too little dissolved, giving sour, sharp, hollow cups. → Under-Extraction and Over-Extraction Over-extraction: too much dissolved, giving bitter, astringent, drying cups. → Under-Extraction and Over-Extraction Varietal: a genetic variety of the coffee plant, e.g. Geisha, Bourbon. → Coffee Varietals Washed process: a processing method that ferments and rinses fruit off the seed. → Washed Process

#Continue Reading

• Describing Coffee: language for what you taste
• The Coffee Flavor Wheel: a map of flavor descriptors
• Pour Over Troubleshooting Guide: apply these terms to fixing a cup
• Master Index: every note these terms point to