Espresso shot runs too fast
The shot reaches its weight much sooner than your usual shots with the same coffee, and often tastes thin or sour. Time is a reading here, not a target.
Applies to: Espresso machine, Espresso
Why a shot runs fast
CoffeeHQ explanation
An espresso machine supplies pressure; the coffee supplies resistance. The speed of a shot is whatever results when the two meet. A shot that gushes means the puck is offering too little resistance, so water passes through before it has had time to dissolve much.
The grind is by far the most common reason. Coarser particles leave larger gaps between them. Too little coffee in the basket has a similar effect, because a shallow puck is easier to push through. Coffee that is well past its roast date also tends to flow faster, since it has lost the gas that helps a fresh puck resist.
The result usually takes little from the coffee: thin, pale and sour, with a crema that vanishes quickly.
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 coarse
- How to check
- Have you changed beans or grinder settings recently?
- What to change
- Grind finer to increase resistance and slow the flow.
Cause 2 of 3 · Commonly the cause
Dose too low
- How to check
- Have you weighed the dose in the basket?
- What to change
- Increase the coffee dose in the basket.
Cause 3 of 3 · Commonly the cause
Uneven tamp or channelling
- How to check
- Does the stream spurt unevenly or run out to one side?
- What to change
- Distribute grounds evenly and tamp level before locking in the portafilter.
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
- Espresso still runs fast with the grinder at its finestThe possibilities, the quickest check and one thing to change first
How it shows up on different brewers
Tendency, not a guarantee
- Unpressurised basket
- Grind finer in small steps. This is the normal case and the one the causes below assume.
- Pressurised basket
- The basket creates most of the resistance, so grind has little effect on time. A fast, thin shot usually means too little coffee or stale coffee.
Easily confused with
- Channelling — A channelled shot can also finish quickly, but it spurts or runs unevenly and tastes bitter as well as sour. Grinding finer makes channelling more likely, not less.
- A grind change that has not taken effect — Grounds from the previous setting stay in the grinder. If you have just adjusted it, the first shot is a mixture; purge a little coffee before judging.
What not to change at the same time
Do not grind finer and increase the dose in the same shot. Both add resistance, and together they often overshoot into a shot that barely drips.
How to tell it is fixed
The stream should start as slow, dark drops and gather into a steady flow the colour of warm honey. Reaching your target weight in roughly 25 to 35 seconds is the usual convention for a starting point, not a tested optimum; taste decides the rest.
Understand the science: Espresso pressure and flow — How pressure, the puck's resistance and flow are linked, and which of them the machine actually sets.
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.