Barista skills
How to dial in espresso: dose, yield and time
A practical method for dialling in espresso. Start at 18 g in, 36 g out in 25–30 seconds, then adjust the grind using taste. Includes a troubleshooting table.
By the Jex Institute training teamUpdated 6 min read
Quick answer
To dial in espresso, fix your dose, choose a target yield and adjust only the grind until the shot tastes balanced. A common starting recipe is 18 g of ground coffee in, 36 g of espresso out, in 25 to 30 seconds. If the shot runs fast and tastes sour, grind finer. If it runs slow and tastes bitter, grind coarser.
Key takeaways
- Weigh the dose and the yield. Guessing by volume hides the problem.
- Change one variable at a time, and grind is the first one to change.
- Sour and thin means under-extracted. Bitter and dry means over-extracted.
- Recalibrate whenever the coffee, the weather or the hopper level changes.
The three numbers that define a shot
Every espresso recipe is built from dose, yield and time. Dose is the weight of dry ground coffee in the basket. Yield is the weight of liquid espresso in the cup. Time is how long the pump runs.
Dose divided into yield gives the brew ratio. 18 g in and 36 g out is a 1:2 ratio, which is the usual starting point for a modern espresso. A shorter ratio such as 1:1.5 is heavier and more intense, and a longer ratio such as 1:2.5 is lighter and clearer.
A step-by-step dialling-in method
- 1
Set the dose for your basket
Use the dose your basket is designed for, often 18 g for a double. Weigh it every time and keep it fixed while you calibrate.
- 2
Distribute and tamp level
Level the grounds, then tamp flat with firm, even pressure. An uneven bed causes channelling, where water rushes through one side.
- 3
Pull a shot onto a scale
Start the timer with the pump and stop the shot when the cup reaches your target yield, for example 36 g.
- 4
Read the time
If the shot reached 36 g in under 20 seconds, the grind is too coarse. If it took more than 35 seconds, the grind is too fine.
- 5
Adjust the grind and purge
Make a small grinder adjustment, then purge a few grams so old grounds do not mix into the next dose.
- 6
Taste and decide
Numbers get you close and taste finishes the job. Keep the recipe that tastes sweet and balanced, even if the time is slightly outside the range.
Espresso troubleshooting table
Match what you see and taste to the most likely cause.
| What you notice | Likely cause | What to change |
|---|---|---|
| Fast shot, sour, thin body | Under-extraction: grind too coarse | Grind finer |
| Slow shot, bitter, dry finish | Over-extraction: grind too fine | Grind coarser |
| Sour and bitter together | Channelling from uneven distribution | Level the bed and tamp flat |
| Pale, thin crema | Stale coffee or water too cool | Use fresher beans, check temperature |
| Spraying from a bottomless portafilter | Clumps or a cracked puck | Break up clumps, tamp once, do not knock the handle |
| Shot time drifts through the day | Heat and humidity changing the grind | Recalibrate in small steps |
When to recalibrate
Calibration is not a once-a-day task. Check the shot at opening, when a new bag or batch goes into the hopper, when the hopper runs low, and when the room warms up or the air conditioning changes. In a busy café the head barista tastes espresso several times a shift.
Practising on commercial equipment
Reading about extraction helps, but the skill comes from pulling many shots and tasting every one. Calibration is taught from the first unit of the Speciality Barista Course and practised on commercial machines. Once your espresso is consistent, move on to milk with our latte art guide for beginners, and read coffee roast levels explained to understand why a light roast needs a different recipe from a dark one.
FAQ
Common questions
What is the ideal espresso ratio?
A 1:2 ratio is the standard starting point, for example 18 g of coffee in and 36 g of espresso out. Adjust shorter for more intensity or longer for more clarity.
How long should an espresso shot take?
Most balanced shots run between 25 and 30 seconds, counted from when the pump starts. Treat the time as a guide and let taste make the final decision.
Why is my espresso sour?
Sour espresso is usually under-extracted. The water passed through too quickly, so grind finer to slow the shot down.
Keep exploring
Courses that teach this
BaristaSpeciality Barista Course
Go beyond the basics and learn the skills that define a professional barista, from precise espresso calibration and milk steaming to latte art, manual brewing and the full café drinks menu.
- Length
- 6 weeks daily, or 2–3 months part-time
- Fee
- AED 1,999
View course
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