requirements of an espresso grinder

 

 

From David Schomer:

A condensed list of additional features and capabilities critical to an espresso grinder includes:

    a) Retention of less than 1 gram (g) of chambered ground coffee
    b) Grinding output speed of no more than 2g per second.
    c) Propulsion of powder into the portafilter with no clumping or micro-particle drift
    d) Cessation of grinding upon achieving an exact dose by gram weight (+/- 0.1g)
    e) Temperature Control: The powder must remain between 32°C to 35°C.

 

outcome: controlled Flow Rate.

for espresso, too-fast shot that reaches full volume in less than 25 seconds will have a flavor profile dominated by sour/astringent notes. Too slow, extracting 25ml in 33 sec, and the flavor might be hollow, sour, or bitter. ( yield extraction)

What features are key in maintaining an ideal flow rate of the shot?

Stepless grind setting adjustments

Dosing by weight

Low retention

type of burrs and configuration:

- affect particle size distribution

particle management :

- affect clumping ( or without), RDT, WDT techniques to reduce channeling

temperature management

as important as all of above:

ergonomics and grinding output speed