Espresso shot runs too slowly
The shot drips and takes much longer than your usual shots to reach its weight, and often tastes bitter or harsh. Time is a reading here, not a target.
Applies to: Espresso machine, Espresso
Why a shot chokes
CoffeeHQ explanation
A shot that only drips, or does not flow at all, means the puck is resisting more than the pump can comfortably push through. Water stays in contact with the coffee far longer than intended and extracts further, which is usually tasted as bitter and harsh.
A grind that is too fine is the usual cause: the particles pack so tightly that there is almost no path through. Overfilling the basket does the same by pressing the coffee against the shower screen. Very fresh coffee, only a few days off roast, can also slow a shot because of the gas it releases.
If shots have slowed gradually over weeks with no change to grind or coffee, suspect the machine. Scale and old coffee residue restrict flow in ways that look exactly like a grind problem.
Causes, most likely first
There are 3 likely causes, listed with the most probable first. Work down the list and change one thing at a time, so that when the problem goes away you know which change fixed it.
Cause 1 of 3 · Commonly the cause
Grind too fine
- How to check
- Have you changed beans or grinder settings recently?
- What to change
- Grind coarser to reduce resistance and speed up the flow.
Cause 2 of 3 · Commonly the cause
Dose too high for the basket
- How to check
- Is the puck mounded above the basket rim before tamping?
- What to change
- Reduce the coffee dose slightly.
Cause 3 of 3 · Reported, not independently verified
Tamp pressure too firm combined with a fine grind
- How to check
- Are you tamping harder than usual to try to fix a previous issue?
- What to change
- Use consistent, moderate tamp pressure rather than compensating with excessive force.
If none of these fixes it
Check the cleaning and descaling guide. Equipment that needs maintenance can cause several of these symptoms at once, and no change of recipe will correct it.
Work through it for your setup
The causes above are general. These go to the part of a diagnostic that takes this symptom one check and one change at a time.
- Make my coffee better: Espresso machineEvery reading for this brewer: the check, and the one thing to change first
- Dialling in espresso: the workflow
- A tiny adjustment swings the shot from gushing to chokingThe possibilities, the quickest check and one thing to change first
How it shows up on different brewers
Tendency, not a guarantee
- Unpressurised basket
- Grind coarser in small steps. Tamping more lightly makes very little difference and is not a substitute.
- Pressurised basket
- These need a coarser grind than a standard basket. Espresso-fine coffee can block the single exit hole entirely.
Easily confused with
- A machine that needs cleaning or descaling — If water runs slowly even with no coffee in the portafilter, the restriction is in the machine and no grind change will fix it.
- An overfilled basket — If the spent puck shows the imprint of the shower screen, there is too much coffee in the basket. Reduce the dose before touching the grinder.
What not to change at the same time
Do not grind coarser and reduce the dose at once. Either may be enough on its own, and doing both commonly swings the shot from choking to gushing.
How to tell it is fixed
The shot should begin to flow within several seconds of starting the pump and reach its target weight without stalling. The harsh, ashy finish should be replaced by something rounder.
Understand the science: Espresso pressure and flow — Why a finer grind raises resistance, and what one study found happens to flow at the finest settings.
Related issues
What to change
Specific adjustments for this symptom, with what each one trades off.
Work it out
Interactive tools that take you through this one change at a time.
Learn the technique
Step-by-step guides to the skills this problem comes from.