How long should an espresso shot take?

The usual answer is 25 to 32 seconds, and it is worth understanding what that number is actually for.

Time is a proxy, not a goal. What you care about is how much of the coffee dissolved into the cup. You cannot measure that at home without a refractometer, but you can measure how long water took to pass through the bed — and that correlates closely enough to be useful.

So: 18 g of coffee, 36 g of espresso in the cup, in 25 to 32 seconds, timed from the moment the pump starts.

Reading the number

• Under 22 seconds — too little resistance. Grind finer.
• 25 to 32 seconds — in the window. Now taste, and adjust by flavour.
• Over 38 seconds — too much resistance. Grind coarser.

Once you are inside the window, stop using time to make decisions and start using taste. Two shots can both take 28 seconds and taste completely different depending on the bean.

Where the timing starts

Machines with a pre-infusion phase — a low-pressure soak before full pressure — complicate this. Some people time from the pump, others from first drip. Pick one and be consistent; the absolute number matters far less than comparing like with like.

When timing lies to you

A channelling shot can land at a perfect 28 seconds and taste terrible, because the time reflects the average and not what happened inside the puck. If your timing is right and the flavour is not, look at the extraction on a bottomless portafilter rather than at the clock.

Timings also drift over a bag’s life. Fresh coffee degasses and runs faster; the same beans at three weeks run slower. That is normal.