Brewing Variables

A reference for the major controllable variables in coffee brewing.

Coffee dose

The mass of dry coffee used.

Water mass

The mass of brewing water; using mass improves repeatability.

Brew ratio

The relationship between coffee dose and beverage water or beverage mass, depending on the convention used.

Grind size

Controls particle surface area and strongly influences flow and extraction.

Temperature

Affects extraction kinetics and interacts with coffee composition.

Agitation

Movement of water and grounds can change contact and extraction uniformity.

Contact time

The duration of interaction between water and coffee, interpreted alongside flow.

Pressure

Especially important in espresso, where pressure and puck resistance shape flow.

Water chemistry

Mineral content and alkalinity affect extraction and sensory balance.