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Volume VI · Updated 14 March 2025

The Coffee Glossary, A to Z.

1,247 working entries across brewing science, green coffee, espresso, latte art, café operations, and sensory & cupping — written by credentialed Q-Graders, reviewed quarterly, and indexed by domain so you can find the term before the steam wand cools.

Entries
1,247
Domains
6
Last review
14 Mar 2025
Languages
EN · ES · JA · DE · KO

Index by Discipline

Six working domains, 1,247 terms total.

The library is grouped the way a working barista thinks: not alphabetically first, but by what they're trying to do at the bench. Pick a domain, scan the panel, jump to the term that day.

  1. 01

    Brewing Science

    218 entries

    The physics and chemistry behind extraction — solubility, diffusion, contact time, water chemistry, and the math that turns ratios into repeatable cups.

    • Hydraulic Channelnoun · brewing-science
    • Extraction Yieldnoun · brewing-science
    • TDSnoun · brewing-science
    • Bypassnoun · brewing-science
    • Drawdownnoun · brewing-science
    Explore Brewing Science →
  2. 02

    Green Coffee

    194 entries

    From cherry to dried seed — processing methods, storage, moisture content, defects, grading, and the vocabulary that sits between the farm gate and the roastery door.

    • Washed Processnoun · green-coffee
    • Honey Processnoun · green-coffee
    • Defect — Quakersnoun · green-coffee
    • Moisture Contentnoun · green-coffee
    • Screen Sizenoun · green-coffee
    Explore Green Coffee →
  3. 03

    Espresso

    271 entries

    The nine-bar craft — puck prep, pressure profiling, shot diagnosis, machine mechanics, and the language baristas use to describe what just left the portafilter.

    • Ristrettonoun · espresso
    • Lungonoun · espresso
    • Cremanoun · espresso
    • Pre-Infusionnoun · espresso
    • Channelingnoun · espresso
    Explore Espresso →
  4. 04

    Latte Art

    112 entries

    Milk as a medium — texture, temperature, the pitcher as instrument, pour geometry, and the named patterns from rosetta to tulip to the still-contested swan.

    • Microfoamnoun · latte-art
    • Rosettanoun · latte-art
    • Free Pournoun · latte-art
    • Tulipnoun · latte-art
    • Contrastnoun · latte-art
    Explore Latte Art →
  5. 05

    Café Operations

    198 entries

    The working language of the floor — workflow, equipment maintenance, calibration, inventory, and the small nouns that keep a busy bar moving at 8:02 on a Monday.

    • Backflushverb · cafe-operations
    • Calibrationnoun · cafe-operations
    • Shot Timernoun · cafe-operations
    • Dosingnoun · cafe-operations
    • Group Headnoun · cafe-operations
    Explore Café Operations →
  6. 06

    Sensory & Cupping

    254 entries

    The descriptive vocabulary of flavor — the SCA flavor wheel, the World Coffee Research Sensory Lexicon, aroma attributes, mouthfeel, and the score-sheet terms a Q-Grader actually writes.

    • Aciditynoun · sensory-cupping
    • Bodynoun · sensory-cupping
    • Flavor Wheelnoun · sensory-cupping
    • Sweetnessnoun · sensory-cupping
    • Aftertastenoun · sensory-cupping
    Explore Sensory & Cupping →

A – Z Jump Rail

Heard a term at the bar? Start with the letter.

Twenty-six drawers, one for each letter of the working alphabet. Letters without entries yet are dimmed — coverage shown honestly, not dressed up.

  1. A74
  2. B96
  3. C138
  4. D82
  5. E61
  6. F94
  7. G47
  8. H53
  9. I29
  10. J18
  11. K22
  12. L71
  13. M89
  14. N43
  15. O27
  16. P102
  17. Q0
  18. R64
  19. S117
  20. T58
  21. U14
  22. V31
  23. W39
  24. X0
  25. Y8
  26. Z0
A Q-Grader evaluating cupping bowls at a sensory table

Photograph for editorial reference only · January 2025 session · Coffee Quality Institute

Today's Featured Entry · 14 March 2025

Extraction Yield /ɪkˈstrakʃən jiːld/

What it is. The percentage, by mass, of the soluble coffee compounds that have moved from the roasted bed into your cup. Most well-developed brewed coffee lands between 18% and 22% extraction yield — a band refined empirically over decades and now used as the working reference for "balanced" extraction on either side of which the cup turns sour (under) or bitter (over).

How it's calculated. Yield (%) = (TDS of the brewed beverage × beverage mass) ÷ (mass of dry coffee ground) × 100. A refractometer gives you the TDS; the rest is bookkeeping — a scale, a notebook, ten minutes of patience.

What it isn't. Extraction yield is not strength. A drink can be high-yield and weak (plenty of solubles, lots of water) or low-yield and strong (few solubles, little water). SCA's strength-and-extraction chart splits the difference — and is the chart on the wall of most roastery QC rooms for good reason.

Watch for. Brew parameters shift the yield before you change the dose — water temperature, contact time, grind distribution, and agitation all move the needle. Treat 20% as a destination, not a setting.


First catalogued
March 2019
Sources
Illy & Viani, "Espresso Coffee: The Science of Quality"; SCA Brewing Handbook (2017 ed.); Lockhart, "The Coffee Brewing Chart"
Editorial review
Quarterly · Q1 2025
Written by
M. Okafor, CQI Q-Grader · J. Renard, WBC Judge

A note from the editorial board

An entry earns its way into this glossary when three things are true at once: the term is in working use across the industry, it has a meaning precise enough to be useful to someone holding a refractometer or a tamper, and at least two credentialed readers can defend that meaning in a sentence. Anything that fails one of those tests gets cut, regardless of how often you see it on Twitter.

We hold ourselves to a quiet standard — every entry is reviewed on a quarterly cycle, every claim is sourced, every recipe is described as a starting point rather than a verdict. Brew parameters vary by equipment, water, and intention; the glossary names what is happening and why, then trusts the reader to apply it. That trust, more than the entry count, is what we are trying to build.

— The Editorial Board, CoffeeGlossary

Eleven Q-Graders, CQI instructors, and WBC finalist judges · Meet the board

Continue your research

Two ways to keep going.

The glossary opens sideways into the rest of CoffeeGlossary — into a once-a-week reading list shipped to 47,000+ subscribers, or into the brewing-methods reference our editors use when they write new entries. Pick the path that fits your week.

Newsletter

The Brew Brief

A weekly, no-chaff email from the editorial desk — one term defined in depth, one brewing question answered with footnotes, one piece of equipment news worth knowing about. Trusted by baristas, roasters, and curious home brewers since 2019.

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Reference

Brewing Methods, A – Z

Thirty brew methods profiled the same way we profile a term — what it is, what it does well, where it falls apart, and the parameters a beginner should sit down with first. Built as a working companion to the glossary.

30 methods · pour-over, espresso, immersion, hybrids

Open the Methods Index