Grinder doser
Rotating cylindrical chamber attached to some professional coffee grinders, storing ground coffee and dispensing it in ~7g doses per paddle action. Less precise than on-demand grinders (grind-to-order). Declining in specialty bars in favour of gram-based dosing.
How does a doser grinder work?
A doser grinder is a commercial espresso grinder design in which ground coffee falls into a cylindrical chamber equipped with a rotating dosing lever. Pulling the lever releases a pre-set quantity of coffee, typically 7g per pull for a single dose, into the portafilter below. Doser grinders dominated commercial espresso bars from the 1960s through the 2000s, with brands like Mazzer and La Marzocco building their reputations on robust doser models (Mazzer Major Doser, Robur). The doser chamber typically holds 40-80g of pre-ground coffee, which creates a significant freshness trade-off: ground coffee in the chamber begins staling immediately, losing volatile aromatics within minutes. This is why the specialty coffee shift toward on-demand (doserless) grinders accelerated after 2005, as on-demand models grind exactly what is needed per shot, eliminating chamber retention.
Should a café choose a doser or on-demand grinder?
Understanding the doser-vs-on-demand distinction is critical for café equipment decisions. High-volume cafés may still benefit from doser grinders for speed: pulling three or four lever doses per portafilter is faster than waiting for an on-demand grind cycle. But this efficiency comes at a freshness cost that matters acutely for single-origin specialty coffees. On-demand doserless grinders (Mazzer Kony-e, Mahlkönig E65S, Victoria Arduino Mythos) produce better cup quality at the cost of slightly slower dosing, the correct choice for specialty-focused cafés serving filter and espresso with distinct flavour profiles. For home use, doser grinders are generally inferior: their chamber design makes it impossible to switch between coffees without contamination, and single-dose grinding is incompatible with the doser mechanism.
Related Terms
Related terms: Coffee grinder, Burrs, Espresso extraction, Dose, Coffee freshness.