Espresso knowledge
Guides, glossary and tips for better espresso – clearly explained.
Espresso glossary
- Dial-in
- The process of setting grind, dose and time so the bean extracts in balance.
- Extraction
- How much soluble matter is drawn from the coffee. Too little = sour, too much = bitter.
- Crema
- The golden-brown foam layer on the espresso – an indicator of freshness and extraction.
- Brew ratio
- Ratio of ground coffee to liquid espresso, e.g. 1:2 (18 g into 36 g).
- Grind size
- How fine the coffee is ground. Finer extracts stronger and slower.
- Puck
- The compressed coffee bed in the portafilter after tamping.
- Preinfusion
- Gently wetting the puck before full pressure, for more even extraction.
- Channeling
- Water finding a path through the puck – a cause of uneven, often bitter shots.