What grind size is ideal for espresso?
The consensus among coffee connoisseurs is that a fine grind creates the best espresso. With a stable pressure of 9 bar, water extracts the desirable flavours, oils, and aromatics evenly, creating the balance and crema that characterise espresso. Push much higher and you risk channelling (water forcing narrow paths through the coffee puck), leading to uneven extraction, bitterness, and weak body.USING A GRIND SETTING THAT IS TOO COARSE – Grinding too coarse, will result in a watery, weak or sour espresso. With a smaller surface area and more space between grinds, water under pressure will flow through coffee in the basket very quickly. This means that espresso can end up quite thin and underwhelming.The Acceptable Range. While 9 bars is ideal, good espresso can be made within a range of 7 to 11 bars. Some modern machines allow pressure profiling, where pressure changes during brewing. This flexibility can help baristas fine-tune their extractions for different coffee beans and desired flavor profiles.