How do I adjust my grinder for espresso?

Dialing in espresso is the essential process of calibrating your equipment to match the specific needs of your coffee beans. Because every coffee has a different density, roast level, and age, there is no single 'perfect' setting that works for everything. Instead, you must treat your grinder as a precision instrument, making small, incremental adjustments to find the sweet spot where the coffee’s acidity, sweetness, and bitterness are in harmony.

To begin, establish a consistent dose—the amount of dry coffee in your portafilter—and a target yield, which is the weight of the liquid espresso in your cup. A common starting point is a 1:2 ratio, such as 18 grams of dry coffee producing 36 grams of liquid espresso. Once you have these variables locked in, the grind size becomes your primary tool for controlling the extraction time. If your shot pulls in under 20 seconds, it is likely under-extracted and sour; you need to grind finer to increase resistance.

Conversely, if your shot takes longer than 35 seconds or barely drips out, it is over-extracted and likely bitter. In this case, you should adjust your grinder to a coarser setting. Remember that even small changes to your grind adjustment can have a massive impact on the final taste. Always purge a small amount of coffee after changing settings to ensure the new grind size is actually what is being dispensed into your basket.

Beyond the numbers, trust your palate. The goal of dialing in is not just to hit a specific time, but to create a shot that tastes delicious to you. If the shot is within the target time but still tastes harsh, you may need to adjust your water temperature or dose. Espresso extraction is a balancing act, and learning to read the flow of the shot is a skill that improves with every cup you pull.