Coffee glossary

Plain-English definitions of the coffee terms you'll meet when building a small-space setup. No jargon, no fake expertise.

• AeroPress

  A compact manual brewer that uses gentle air pressure to push water through coffee and a paper filter.

• Bean-to-cup machine

  An automatic machine that grinds, doses and brews coffee at the push of a button.

• Blade grinder

  A grinder that chops beans with a spinning blade, producing an uneven mix of fine and coarse particles.

• Bloom

  The initial pour that wets the grounds and lets fresh coffee release trapped gas before the main brew.

• Boiler

  A tank that heats and holds water in an espresso machine, offering steadier temperature than a thermoblock.

• Brew ratio

  The proportion of coffee to water in a brew, such as 1:16 for filter or 1:2 for espresso.

• Burr grinder

  A grinder that crushes beans between two abrasive burrs to produce a consistent, adjustable grind size.

• Channeling

  When water finds a path of least resistance through the coffee bed, extracting unevenly.

• Coffee scale

  A precise scale, often with a timer, used to weigh coffee and water for repeatable brewing.

• Coffee storage

  How you keep coffee to protect it from the air, light, heat and moisture that cause it to go stale.

• Conical burr

  A burr set with a cone-shaped inner burr inside a ring burr, common in compact grinders.

• Crema

  The reddish-brown foam that sits on top of a freshly pulled espresso shot.

• Degassing

  The release of carbon dioxide from coffee in the days after roasting.

• Descaling

  Removing limescale build-up from a coffee machine's water path, especially in hard-water areas.

• Distribution tool

  A tool that levels and evens out the grounds in the portafilter before tamping.

• Espresso

  A small, concentrated coffee made by forcing hot water through finely ground coffee under pressure.

• Espresso machine pressure

  The brewing pressure used to make espresso, traditionally around 9 bar at the coffee.

• Extraction

  The process of dissolving flavour compounds out of ground coffee into water.

• Filter coffee

  Coffee brewed by letting water pass through grounds and a filter, producing a lighter, longer drink than espresso.

• Flat burr

  A burr set with two flat, ring-shaped burrs that face each other, common in larger espresso grinders.

• French press

  An immersion brewer where coffee steeps in hot water before a mesh plunger separates the grounds.

• Gooseneck kettle

  A kettle with a long, narrow, curved spout that pours a slow, precise stream of water.

• Grind size

  How coarse or fine the coffee is ground, which controls how fast water extracts flavour.

• Grinder calibration

  Adjusting a grinder so its settings line up correctly with the grind sizes you want.

• Microfoam

  Smooth, velvety steamed milk with tiny, barely visible bubbles, used for flat whites and latte art.

• Milk frothing

  Adding air and texture to milk to make it foamy for drinks like cappuccinos and lattes.

• Moka pot

  A stovetop pot that makes strong, espresso-style coffee using steam pressure.

• Non-pressurised basket

  A traditional single-wall espresso basket that relies entirely on your grind and tamp to build pressure.

• PID temperature control

  An electronic controller that holds an espresso machine's brew temperature more steadily.

• Portafilter

  The handled metal holder that clamps the coffee basket into an espresso machine's group head.

• Pour-over

  A filter method where you pour hot water over coffee in a cone-shaped dripper.

• Pressurised basket

  An espresso filter basket with a restrictor that builds pressure for you, making it forgiving of grind and technique.

• Retention

  Coffee grounds left stuck inside a grinder after grinding.

• Roast date

  The date coffee was roasted, a better freshness guide than a distant best-before date.

• Single dosing

  Grinding only the exact amount of coffee you need for one brew, rather than storing beans in a hopper.

• Small-space coffee setup

  A coffee setup chosen to make great coffee while fitting a flat, rental or compact kitchen.

• Steam wand

  A nozzle on an espresso machine that releases steam to heat and texture milk.

• Tamping

  Pressing the ground coffee in the portafilter into a level, compact puck before brewing espresso.

• Thermoblock

  A compact heating system that heats water on demand as it passes through, used in many small espresso machines.

• Water temperature

  How hot the brewing water is, which affects how much flavour is extracted.