Reference · 36 terms

Coffee words, explained.

Coffee has its own vocabulary. Most of it sounds harder than it is. Here’s every word we use on this site, in one sentence each. If we missed one, tell us and we’ll add it.

B

Basket: The metal cup inside a portafilter where the coffee sits.; Cheap baskets have uneven holes; precision baskets are laser-drilled and pour more evenly. One of the biggest cheap upgrades on entry-level machines.; See also:portafilter dose
Bloom: The first pour in a pour-over — just enough water to wet the grounds and let gas escape.; Fresh coffee gives off CO₂. The bloom is a 30-second pause that lets the bed degas, so the rest of the water can actually extract flavor instead of pushing past bubbles.; See also:pour over extraction
Blooming pour: The first pour in a pour-over — roughly 2× the weight of coffee, poured slowly.; For 15 g of coffee, bloom with ~30 g of water for ~30 seconds. Watch for bubbles to slow before continuing.; See also:bloom pour over
Burr: The two metal discs inside a proper grinder that crush coffee into a consistent size.; Flat burrs and conical burrs taste different — flats are usually more uniform, conicals more textured. Either works.; See also:grinder fines

C

Channel of shame: Affectionate term for a visibly bad shot from a bottomless portafilter.; You'll see a thin jet shoot out one side at high speed. We've all made one. Re-distribute, re-tamp, try again.; See also:channeling portafilter
Channeling: When water finds an easy path through the coffee bed instead of flowing evenly.; Caused by uneven distribution, a soft tamp, or a too-fine grind. The result is sour, weak shots — water extracted everything in one spot and skipped the rest.; See also:distribution wdt tamp

D

Dialing in: The process of adjusting grind, dose, and time until a coffee tastes the way you want.; When you switch beans, you usually need to dial in again — grind one step finer or coarser, taste, adjust, repeat. Three to five shots is normal.; See also:grind size ratio shot
Distribution: Spreading the grounds evenly in the basket so water flows through evenly.; The fix for most beginner channeling problems. A WDT tool (or any thin pin, honestly) breaks up clumps before you tamp.; See also:channeling wdt tamp
Dose: The weight of dry coffee you put into the portafilter, in grams.; Most 58 mm baskets are designed for 17–19 g. Going higher is fine if you grind coarser to compensate; going lower works if you grind finer.; See also:ratio yield portafilter
Dosing cup: A small cup you grind into, then transfer from. Keeps grounds where they belong.; Solves the 'half my coffee is on the counter' problem most beginners don't realize they have.; See also:dose
Drip bag: A single-serve pour-over: pre-ground coffee in a paper bag that hooks over a mug.; Just add hot water. The easiest possible filter coffee — good for travel, the office, or trying a new bean without committing to gear.; See also:pour over
Drip coffee: Filter coffee — water passes through grounds via gravity, not pressure.; Pour-overs are drip. So are automatic coffee makers. The opposite of espresso.; See also:pour over drip bag

E

Espresso: Concentrated coffee made by forcing hot water through a tightly packed bed of fine grounds.; 30–35 ml of liquid out, usually in 25–30 seconds. Everything else in espresso — milk drinks, americano — starts here.; See also:shot portafilter ratio
Extraction: What the water pulls out of the coffee — flavor, oils, acidity, bitterness, the lot.; Under-extract: sour. Over-extract: bitter. Just right: balanced. Most of dialing in is moving along that curve until you like where you are.; See also:dialing in sour bitter

F

Fines: The dust-fine particles that come out of any grinder, no matter how good.; Fines extract faster than the rest of the grounds and can over-extract bitterness or clog the basket. Better grinders make fewer of them.; See also:grind size

G

Grind size: How fine or coarse the coffee is ground — finer = slower flow, coarser = faster.; Espresso wants fine (~250 microns). Pour-over wants medium (~600 microns). French press wants coarse (~900 microns). A scale to grind is a normal step.; See also:dialing in extraction
Grinder: The single most important piece of gear in your setup — more than the machine.; A bad grinder makes consistent coffee impossible. If you're choosing between upgrading the machine or the grinder, upgrade the grinder.; See also:grind size retention fines

H

Headspace: The gap between the puck and the shower screen when you lock the portafilter in.; Too little headspace and water can't bloom across the puck. Too much and the puck swells. Aim for 2–4 mm.; See also:puck portafilter

M

Microfoam: Milk steamed to a smooth, paint-like texture — no big bubbles, no thin liquid layer.; What latte art is poured into. Steam with the wand just below the surface until you hear a soft tearing sound, then dive deeper to swirl.
Milk jug / pitcher: The stainless jug you steam milk in.; Spout shape matters more than capacity for latte art. 350 ml is a comfortable size for one or two drinks.; See also:microfoam

P

Portafilter: The handle-and-basket assembly you lock into an espresso machine.; Comes in two main sizes — 58 mm (most prosumer machines) and 51 mm (most home machines). Bottomless portafilters have no spout, which makes channeling visible.; See also:basket headspace
Pour-over: Filter coffee made by pouring hot water by hand over a bed of grounds in a cone.; Most common cones: V60, Kalita Wave, Origami. Each behaves a little differently. The cone is less important than your grind, water, and pour technique.; See also:bloom drip bag
Pre-infusion: A gentle, low-pressure wet of the puck before full pressure starts.; Some espresso machines do this automatically; on others you can mimic it by slow-starting the pump. Helps with channeling on stubborn beans.; See also:puck channeling
Puck: The disc of coffee in the basket — formed by your dose, distribution, and tamp.; After the shot, the puck should pop out as a clean, dry disc. Sloppy, soaked, or cracked pucks usually mean something went wrong upstream.; See also:dose tamp headspace

R

Ratio: How much coffee in vs. how much liquid out — usually written 1:2.; Espresso ratio: 18 g in, ~36 g out = 1:2. Pour-over: 15 g in, 250 g water = 1:16.7. Once you have a ratio you like, keep it stable while you change other variables.; See also:dose yield
Refractometer: A small gadget that measures how much coffee is dissolved in your cup.; Useful for serious dialing in. Yes, you can ignore this for a while — most of us did.; See also:extraction
Retention: Grounds that stay inside the grinder instead of coming out with your dose.; Bad retention means you weigh 18 g in but only 17.6 g comes out. Single-dosing grinders (you weigh in for each shot) have lower retention.; See also:grinder
Rosetta: A specific latte art pattern — looks like a leaf with a stem running through it.; First pattern most people learn after the heart. Takes weeks of bad attempts. That's normal.; See also:microfoam

S

Shot: A single serving of espresso — typically 30–40 ml in 25–30 seconds.; Two simultaneous shots from one portafilter is a 'double'; that's the standard for most home setups.; See also:espresso yield ratio
Single-dosing: Weighing out one shot's worth of beans, putting them in the grinder, grinding them all.; Opposite of leaving beans in the hopper. Better for freshness and means less retention waste — but slower.; See also:retention grinder
Sour vs. bitter: Two ways an espresso can go wrong — sour = under-extracted, bitter = over-extracted.; Sour: grind finer, or pull longer. Bitter: grind coarser, or pull shorter. If it's both, you have a distribution problem, not an extraction one.; See also:extraction channeling

T

Tamp: Pressing the coffee bed flat in the basket before locking the portafilter.; Tamp until the puck stops moving — usually around 15 kg of pressure. Level is way more important than hard. A calibrated tamper takes the variable out.; See also:puck channeling
TDS: Total Dissolved Solids — how strong your cup is, measured by a refractometer.; Espresso TDS is typically 8–12%; filter coffee is 1.2–1.5%. The number you actually need to learn is your own preference, which is fine to find by taste alone.; See also:refractometer extraction

V

V60: A specific brand of pour-over cone (Hario's), but the name people use for any 60-degree cone.; Spirals on the inside help the filter sit slightly off the wall, which lets air escape during brewing.; See also:pour over

W

WDT: Weiss Distribution Technique — stirring the coffee bed with thin needles before tamping.; Breaks up clumps from the grinder, evens out the bed, drastically reduces channeling. The thing that fixes the most beginner shots in our studio.; See also:distribution channeling

Y

Yield: How much liquid coffee comes out — measured in grams.; For espresso, you almost always weigh your yield rather than measure volume — crema makes volume unreliable. 36 g of liquid is 36 g of liquid; 36 ml might be 25 ml of liquid with foam.; See also:ratio dose shot