Dose (Extraction)
Dose refers to the precise weight of dry ground coffee used as the input for a brew — it is always measured in grams on a scale, not by volume or scoops, which introduce inconsistency. Typical targets: 18–20 g for a double espresso, 15–20 g for 300 ml of filter coffee (brew ratio 1:15–1:17), and 15–20 g for AeroPress. Dose is one of the three core variables in any extraction recipe alongside grind size and water, and it directly determines TDS (strength) and extraction yield: increasing dose while holding water constant raises strength but can lower extraction percentage if flow is impeded.
Background & Context
Dose refers to the mass of dry coffee used in a single brewing preparation, typically measured in grams. In espresso, the dose is the mass of ground coffee loaded into the portafilter basket before extraction — modern specialty double shot doses range from 16g to 22g depending on basket size and style. In filter brewing, dose is one half of the brew ratio equation (dose:water). The relationship between dose and extraction yield is counterintuitive: holding water volume constant and increasing the dose does not simply make the coffee stronger — it also decreases extraction yield (EY), because there is less water available per gram of coffee to dissolve solubles. This is why the SCA Brewing Control Chart operates as a two-dimensional tool: you cannot read cup quality from dose alone without knowing water volume. In espresso, the dose determines the puck height in the basket — too low a dose creates a thin puck that extracts unevenly; too high a dose compresses the basket's headspace and increases extraction resistance. Single-dose grinders (designed to grind exactly the dose needed for one shot, minimising retention) have become a specialty standard, as traditional grinders with hoppers can retain stale coffee from previous sessions.
Practical Use
For espresso: start with the dose recommended for your basket (usually marked inside — 18g basket works best at 16–18g). Adjust dose in 0.5g increments as part of the dialing-in process. For filter: use a kitchen scale to weigh both coffee and water to the gram — volume measurements (scoops, tablespoons) are unreliable. A standard starting dose for V60 is 15g coffee per 250ml water (1:16 ratio).
Related Terms
Related terms: Brew ratio — dose is one variable of the ratio. Extraction yield — dose affects EY when water is held constant. Espresso extraction — where dose is most precisely controlled. TDS — strength is partly determined by dose.