Guide
Espresso Puck Prep: Distribution & Tamping (Step by Step)
After the grind, puck prep is what separates an even, sweet shot from a sour-and-bitter mess. Here is how to do it right.
Why puck prep matters
Water takes the path of least resistance. If your coffee bed is uneven or clumpy, water 'channels' through the weak spots — over-extracting some grounds (bitter) and under-extracting others (sour) in the same shot. Good puck prep makes the bed even so water flows uniformly. It fixes more home-espresso problems than almost anything except the grind.
Step by step
- Grind directly into a dry portafilter basket.
- Distribute: break up clumps and even out the grounds — a WDT tool (a few fine needles stirred gently through the grounds) works best; otherwise a light tap and stir.
- Level the bed so it is flat across the basket.
- Tamp firmly and, above all, level — consistency matters far more than brute force.
- Wipe the rim clean and lock the portafilter into the group, then brew promptly.
Common causes of channeling
- Uneven distribution before tamping
- A crooked (angled) tamp
- Clumpy, static-y grind that wasn't broken up
- Dose too high or low for the basket size
Watch it done
▶ Watch video tutorials on YouTube
FAQ
How hard should I tamp espresso?
Firm and, crucially, level — but consistency beats force. Once the grounds are compressed there is little benefit to pressing harder; an even, repeatable tamp matters far more.
What is WDT?
The Weiss Distribution Technique: gently stirring fine needles through the grounds in the basket to break up clumps and even the bed before tamping. It is one of the most effective anti-channeling habits.
Do I need a distribution tool?
It helps, but a careful manual stir-and-level works too. The goal is simply an even, clump-free, level bed before you tamp.
Recommended gear
Putting this into practice? Browse our espresso machine reviews and grinder reviews — or start with the Breville Barista Express, our pick for most home baristas.