Thin, pale, watery output that fills the cup in ten seconds means the water is not meeting the coffee properly.
Grind too coarse
The commonest cause by a wide margin. Espresso needs a much finer grind than most people expect — like flour, and it should clump slightly when squeezed.
If you are using a grinder that cannot go fine enough — most cheap grinders and all blade grinders — no other adjustment will fix this.
Dose too low
A basket designed for 18 g and given 12 g has too much headspace. Water pools and pushes through.
Fill the basket to its rating, level it, and tamp.
Pre-ground coffee
Supermarket pre-ground is milled for filter machines, not espresso. It is far too coarse.
This is the single most common cause of the problem and the one least often recognised.
The wrong basket
A single-wall basket with pre-ground coffee gushes. A pressurised basket with properly fine espresso grind chokes.
Check which you have — one small hole in a second layer means pressurised.
Channelling
If the grind is right and the shot still gushes, water is finding a route through. A bottomless portafilter will show it.
Fix with WDT and a level tamp.
The order
Grind finer. Increase the dose. Check the basket type. Then look at puck prep.
Last reviewed 8 August 2026