How to Adjust Grind Size for Espresso Extraction Espresso Grind Coarseness Standards

Whether for pour-over coffee or espresso, grind size stands as the most crucial parameter in coffee extraction, yet it remains the most challenging to master with precision.

Often, we only know that espresso requires a much finer grind than pour-over coffee, but there's no straightforward data to explain exactly how fine. Compared to pour-over grind size, FrontStreet Coffee believes finding the suitable espresso grind size is even more difficult.

With pour-over grind size, we can use sieves for calibration, and there's considerable tolerance - a 70-80% pass rate through a #20 sieve can still produce an excellent cup of coffee.

Espresso, however, involves pressurized short-time extraction, which means it amplifies all characteristics - both good and flawed. This creates much stricter requirements for grind size. If the grind is slightly too fine, water passes through the coffee bed more slowly, leading to over-extraction. If the grind is slightly too coarse, water flows through too quickly, causing under-extraction. Such deviation might result from a mere 0.1 difference in grind setting.

Finding Your Perfect Espresso Grind Size

If you're a beginner looking to quickly find the appropriate espresso grind size, you can follow FrontStreet Coffee's step-by-step method below.

Step 1: Initially Lock in the Grind Range

This step is designed for beginners new to espresso coffee. Start by adjusting the grind to a flour-like texture - you should be able to feel the coffee grounds with your hand, soft and smooth without any roughness.

Then apply the commonly used espresso extraction formula: a coffee-to-liquid ratio of 1:2, with extraction time between 20-30 seconds. The coffee dose should match the standard indicated on your portafilter basket - for example, use 18g for an 18g basket or 20g for a 20g basket. With these two parameters (dose and ratio) fixed, adjust the grind size to control extraction time within the 20-30 second range. If extraction exceeds 30 seconds, make the grind coarser for the next shot. If extraction falls below 20 seconds, make the grind finer.

Step 2: Adjust Based on Flavor and Extraction Feedback

Once you've found a grind setting that produces extraction times between 20-30 seconds, you can proceed to the next step - fine-tuning based on actual results.

Because the common extraction formula represents an ideal scenario, in reality, different coffee beans, different espresso machines, and other factors mean that even if you follow this formula perfectly, the result may not necessarily taste good (if you're satisfied with the taste after trying, you can skip this step). Therefore, we need to taste and then make fine adjustments based on flavor performance.

Now, the adjustment target is solely the grind size, but dose and ratio can also be included in adjustment parameters. If the espresso flavor is overly acidic with insufficient body, you need to make the grind even finer. If the coffee exhibits burnt or bitter flavors, you can make the grind coarser or increase the ratio (for example, to 1:1.8).

When you've adjusted to suit your personal taste, the current grind setting is the espresso grind size you need.

Why Fresh Grinding Matters

Some friends ask FrontStreet Coffee, "I don't know how to adjust grind size, can you grind the coffee into powder and send it to me?" Although FrontStreet Coffee can offer pre-grinding services, we generally recommend purchasing whole beans and grinding them yourself. There are two reasons for this. The first is freshness - espresso grounds are much finer than pour-over grounds, which means coffee flavor compounds dissipate more quickly, and carbon dioxide releases faster. When most of the gas has escaped, it becomes difficult to produce good crema, and the coffee flavor becomes less appealing.

The second reason is that espresso grind size is not fixed. In fact, espresso grind settings are affected by degassing levels and weather conditions, requiring almost daily micro-adjustments to ensure consistent extraction quality. If using pre-ground coffee, parameters that worked well a few days ago may become unstable afterward.

Therefore, if you want to make espresso yourself, learning to adjust grind size and purchasing whole espresso beans are the best approaches.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473