Why coffee beans give their best
If you want a perfect espresso at home, it all starts with the bean. Coffee beans preserve aromas and essential oils far longer than ground coffee, because the surface exposed to air and moisture is kept to a minimum. Once ground, coffee begins to oxidise and lose its aromatic compounds within a few minutes: that's why grinding fresh, just before extraction, makes an enormous difference in the cup.
Starting from beans also means being able to adjust the grind according to your machine and your taste, a freedom that pre-packaged coffee does not offer. In this guide we look step by step at how to choose the grinder, find the right grind size, dose correctly and manage the extraction parameters.
Choosing the coffee grinder
The coffee grinder is the most important tool, even before the machine. For espresso, what matters above all is the uniformity of the grind: particles of different sizes extract at different times, together producing both sour and bitter notes.
- Burr grinder (conical or flat): guarantees a uniform grind that can be adjusted with precision. It's the recommended choice for espresso.
- Blade grinder: cheaper, but it breaks the beans unevenly and heats the coffee. Poorly suited to espresso.
- Fine adjustment: check that the grinder offers many settings or a stepless adjustment, because espresso requires micro-adjustments.
The right grind for espresso
For espresso the grind must be fine. The contact time between water and coffee is short, so a large extraction surface is needed: a fine grind, similar to fine salt or slightly finer, exposes more coffee to the hot water in the little time available.
How to tell if the grind is right
The grind is adjusted by observing the extraction time. If the espresso flows down too quickly, the grind is too coarse: the water passes through without extracting enough and the cup turns out watery and lacking body. If instead it drips down and takes too long, the grind is too fine: the result is an over-extracted and bitter coffee. The practical rule is simple: adjust the grind, not the other parameters, until you are back within the correct time.
The correct dose
The classic dose for a single espresso is about 7-9 grams of ground coffee. This amount, distributed evenly in the filter, offers the right resistance to the passage of water.
- Dose too low: the water finds little resistance, the extraction is fast and the coffee turns out weak and lacking aroma.
- Dose too high: the puck is too compact, the water struggles to pass through and the espresso comes out slow and bitter.
- Consistency: always use the same dose so you can compare the results and isolate the variable to correct. A precision scale helps a great deal.
Tamping and extraction: the parameters of the perfect espresso
Once the coffee is dosed in the filter, it must be tamped (tamping or tamping) with firm and even pressure, keeping the tamper straight. The goal is to create a compact and level puck, so that the water passes through it uniformly without opening preferential channels.
The reference parameters for a perfect espresso, confirmed by the leading guides in the sector, are:
- Extraction time: about 25-30 seconds from the start of the pour.
- Water temperature: between 90 °C and 96 °C; darker roasts tend to prefer the lower part of this range.
- Pressure: around 9 bar, the standard value of espresso machines.
- Dose: about 7-9 grams for a single espresso.
These parameters work together: changing one often requires rebalancing the others. In practice, fix the dose, temperature and pressure and use the grind as the main lever to hit the 25-30 seconds.
Common mistakes to avoid
- Grinding in advance: coffee loses its aromas quickly. Grind only the amount you need, on the spot.
- Ignoring the extraction time: it's the most important signal. If you're outside the 25-30 seconds, adjust the grind.
- Uneven tamping: a crooked or loosely packed puck creates water channels and an uneven extraction.
- Variable dose: changing the amount with every coffee makes it impossible to understand what to correct.
- Water too hot or too cold: outside the 90-96 °C range, burnt or sour and under-extracted notes appear.
Conclusion
Making a perfect espresso at home is not a matter of luck: it depends on fresh beans, the right grind, a consistent dose and respecting the extraction parameters. With a good coffee grinder and a little practice in reading the pour time, the cup improves immediately and noticeably.
Want to start with the right raw material? Discover our selection of coffee beans and the Caffè Borbone blends: the first step towards your perfect espresso starts with the bean.
