WDT makes no difference to the shot

Stirring the grounds before tamping changes neither the flow nor the taste of the espresso.

Applies to: Espresso machine, Espresso

Likely causes and adjustments

Try one adjustment at a time so you know what actually changed the result. Start with the first cause below — if it doesn't help, reveal the next.

Cause 1 of 4 · Commonly the cause
A pressurised (dual-wall) basket is fitted
Does the basket have one small hole underneath rather than many fine ones?
Check the underside of the basket for a single small hole. A pressurised basket sets the flow mechanically, so distribution has almost no effect.

Step-by-step guides to the skills this problem comes from.

Distributing espresso grounds (WDT)Leave the coffee bed uniformly dense throughout, so water meets the same resistance everywhere and does not carve a channel.