Daily Espresso Calibration for Coffee Shops
How to dial in espresso every morning: dose, yield and time, and how to read sour or bitter shots to adjust the grind.
An espresso that tasted great yesterday may not taste the same today. Humidity, bean age and room temperature all change how the coffee grinds. That is why baristas in good shops dial in every morning before opening, and every time they open a new bag.
Starting numbers
- Dose: 18 g of ground coffee in a double basket.
- Yield: 36 g of espresso in the cup, a 1:2 ratio.
- Time: 25 to 30 seconds from pressing the button.
- Water temperature: about 90 to 94°C, set on the machine.
These are common starting points. Some beans taste better at a slightly different ratio. What matters is that once you find the right numbers, every barista uses them.
How to dial in
- Let the machine warm up fully, then flush the group head.
- Weigh 18 g of coffee, level it and tamp with the same pressure every time.
- Put the cup on a scale and start the timer with the shot button.
- Stop when the scale reads 36 g. Note the time.
- Taste it. Do not rely on time alone: flavour is the final judge.
Reading the taste
| What happens | What it means | What to change |
|---|---|---|
| Runs too fast (under 25 seconds), sharp sour taste, thin | Under-extracted | Grind finer |
| Runs too slow (over 30 seconds), bitter, drying | Over-extracted | Grind coarser |
| Time is right but not sweet enough | Ratio does not suit this bean yet | Try a 38–40 g yield or an 18.5 g dose |
Key rules
- Change only one thing at a time. If you change grind and dose together, you will not know which one fixed the taste.
- Discard 1 or 2 shots after changing the grind, because old grounds are still in the grinder.
- Log the results in a notebook or on the bar board: date, bean, dose, yield, time and taste.
- Check again around midday if the shop is busy or the temperature changes a lot.
Once the espresso is right, every drink built on it improves: americano, cappuccino, piccolo latte and iced coffee milk. Read more about extraction in our Coffee Guide.
