Good espresso comes down to three numbers: 18 g in, 36 g out, 25 to 32 seconds. Start the shot timer when you start the pump, stop it at 36 g, and it tells you whether to grind finer or coarser.
Coffee in
18 g
In the cup
36 g
Ratio
1:2
Water temp
93 °C
Grind
Finefiner than table salt, like fine sand
Shot time
25–32 s
Guided BrewEspresso
0.0target 25–32 s
Start the shotStart with the pump, stop at the target weight.
0:00Start the shot
0:06First drops
0:20Watch the scale
0:28Aim for 36 g
What you need
Espresso machine with a double basket
Espresso grinder that adjusts in small steps
Scale under the cup, ideally in 0.1 g steps
Tamper, and a WDT tool (needle distributor) if you have one
18 g of fresh coffee, roasted for espresso or filter
Prepare the puck
Grind 18 g of coffee fine, finer than table salt, like fine sand. It may clump a little, but it should not be a powder like flour. Put it in the basket and stir it with a WDT tool to break up clumps. No WDT tool? A gentle tap at least levels the bed. Then tamp it level with firm, even pressure. Wipe the rim, flush the group head for two seconds, put the cup on the scale and tare it to zero, then lock in the portafilter and start right away.
Pulling the shot
0:00
Start the shot
Start the pump and the timer at the same moment, with the cup on a scale tared to zero.
0:06
First drops
Dark, syrupy drops should appear after 5 to 10 seconds, a little later if your machine pre-infuses. Still nothing after 12 seconds without pre-infusion? Grind coarser next time.
0:20
Watch the scale
The stream turns lighter and thinner. Get ready to stop.
0:28
Aim for 36 g
Stop the shot 1 to 2 g before 36 g; the last drops bring it to 36 g. That should take 25 to 32 seconds. The timer then tells you what to change.
Dial it in
Keep 18 g in and 36 g out, and change only the grind until the time lands between 25 and 32 seconds. Then adjust by taste.
The shot took
It usually tastes
Next shot
Under 20 s
Sour, salty, thin
Grind clearly finer
20–25 s
A little sharp
Grind a touch finer
25–32 s
Balanced
Fine-tune by taste
32–37 s
A little bitter, heavy
Grind a touch coarser
Over 37 s
Bitter, dry, ashy
Grind clearly coarser
Light roasts often taste better with a longer ratio, 1:2.5 (18 g in, 45 g out); dark roasts with a shorter one, 1:1.5 to 1:2.
Which coffee works best
Espresso blends and medium roasts are the easiest to dial in. Light roasts can be stunning but need a finer grind, a longer ratio and often a hotter machine, 94 to 96 °C.
FAQ
What is the standard espresso ratio?
1:2 is the modern starting point: 18 g of coffee for 36 g of espresso. A ristretto is around 1:1 to 1:1.5, a lungo 1:3 and longer.
How long should an espresso shot take?
25 to 32 seconds from pressing the button, including the first seconds before any drops appear. That is a general rule of thumb. Once you know your machine and grinder, your balanced shots land closer together, often between 26 and 30 seconds. Use the time to dial in and your taste to decide.
Why is my espresso sour?
It's under-extracted: the water ran through too fast. Grind finer. If the shot is already slow and still sour, try a longer ratio or a hotter temperature.
Why is my espresso bitter?
It's over-extracted: ground too fine, or the shot ran too long. Grind coarser or stop earlier. Very dark roasts taste bitter even when dialed in; try a cooler 90 °C.