WDT tool

A handle holding 4–8 very fine needles (usually 0.3–0.4 mm acupuncture-style) used to stir the grounds in the basket after dosing and before tamping. WDT stands for Weiss Distribution Technique, after the barista who popularised it.

Why it matters — Even a perfect grinder produces some clumping, especially with light roasts and natural processed coffees. Stirring with WDT needles breaks the clumps and produces a much more uniform puck density — which means less channelling and more consistent shots.

Good to know

• One of the cheapest upgrades that produces an obvious improvement in shot quality.
• Stir gently, in small circles, just deep enough to reach the bottom of the puck — too aggressive and you mound the centre.

Related: WDT Tools