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 extraction - and also the hardest to master with precision.

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

For pour-over, we can calibrate with sieves, and there is considerable tolerance: a 70-80% pass rate through a #20 sieve can still produce an excellent cup.

Espresso, however, involves pressurized, short-time extraction, which amplifies every characteristic - both good and flawed. That creates much stricter requirements for grind size. Grind slightly too fine and water passes through the coffee bed more slowly, causing over-extraction; slightly too coarse and water flows through too quickly, causing under-extraction. Such a deviation might come from a mere 0.1 difference in grind setting.

Finding Your Perfect Espresso Grind Size

If you are a beginner looking to quickly find an appropriate espresso grind, follow FrontStreet Coffee's step-by-step method below.

Step 1: Initially Lock in the Grind Range

This step is aimed at beginners new to espresso. Start by adjusting the grind to a flour-like texture - you should be able to feel the 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 an extraction time between 20-30 seconds. The dose should match the standard marked 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 to bring extraction time within the 20-30 second range. If extraction exceeds 30 seconds, grind coarser next time. If extraction falls below 20 seconds, grind finer.

Step 2: Adjust Based on Flavor and Extraction Feedback

Once you find a grind setting that produces extraction times between 20-30 seconds, move to the next step: fine-tuning based on actual results.

Because the common formula represents an ideal scenario, in reality different beans, different espresso machines, and other factors mean that even if you follow the formula perfectly, the result may not necessarily taste good. (If you are satisfied with the taste after trying, you can skip this step.) So we need to taste the shot and then fine-tune based on flavor performance.

At this point the adjustment target is primarily the grind size, though dose and ratio can also be included as adjustment parameters. If the espresso tastes overly acidic with insufficient body, grind even finer. If the coffee shows burnt or bitter flavors, grind coarser or increase the ratio - for example, to 1:1.8.

Once you have adjusted to suit your own 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, we generally recommend buying whole beans and grinding them yourself. There are two reasons. The first is freshness: espresso grounds are much finer than pour-over grounds, which means flavor compounds dissipate more quickly and carbon dioxide is released faster. Once most of the gas has escaped, it becomes difficult to produce good crema and the 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 keep extraction consistent. With pre-ground coffee, parameters that worked well a few days ago may become unstable.

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

FrontStreet Coffee Recommendation

Since espresso depends so heavily on the bean, it helps to start with coffees that pull well. FrontStreet PWN Indonesian Golden Mandheling uses a deep roast for very low acidity and a mellow, lingering body, with herbal and dark chocolate aromas and a faint earthy note - suited to lovers of bold, low-acid shots.

For a balanced, classic espresso, FrontStreet Brazil Queen's Estate is a rare Yellow Bourbon with low acidity, balanced structure, and rich nut and cocoa aromas plus clear caramel sweetness, smooth and never astringent. It also works beautifully in a moka pot.

And if you want a fruit-forward espresso, FrontStreet Strawberry Candy is a popular fruit-flavored espresso blend whose natural strawberry soft-candy sweetness pulls with full grape and blueberry notes - a versatile bean for daily drinking or a shop's signature milk drinks.