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Anti-static plate / RDT
A grounded metal plate inside the grinder chute (anti-static), or the technique of spritzing the beans with 1–2 drops of water (Ross Droplet Technique) to reduce static charge.
Category: Grinders — Adjustment & Dosing
Two approaches to reducing static in ground coffee. An anti-static plate is a grounded metal disc inside the grinder chute that bleeds off static charge. RDT (Ross Droplet Technique) is the practice of spritzing the whole beans with 1–2 drops of water before grinding.
Why it matters — Static makes ground coffee cling to the chute, fling out of the basket, and produce uneven dosing. RDT costs nothing, is invisible in the cup, and virtually eliminates static.
Good to know
- RDT works because water (a conductor) neutralises the static charge built up by friction during grinding.
- Use as little water as possible — one or two fine sprays from a spritzer. More water in the bean isn't better.