How Does Grind Size Affect Espresso and Cafe Americano Ratio?

Espresso grind size adjustment comes down to the gap between the grinder burrs: a narrower gap gives finer particles, a denser puck, more resistance to water, and a longer extraction time. A wider gap gives coarser grounds, faster flow, and shorter extraction. Baristas recalibrate regularly because beans and burrs keep changing.

Many cafes reset their grind setting daily, and strict shops recheck every five hours or so, since moisture content, storage time, air pressure, temperature, and humidity all shift extraction under high pressure. Getting the grind right also sets up related ratios; the cafe americano ratio, for instance, depends on an espresso shot pulled consistently, and a deep roast bean may need a coarser setting.

To pull a proper espresso, adjusting the grinder's grind setting is an unavoidable daily task. Why do cafes adjust their grinders so frequently? How does the coarseness of the grounds affect water flow and extraction time? And how do you tell whether the grind is right? This article starts with why adjustment is necessary, then breaks down the specific methods for dialing in both standard and electronic grinders, including the relationship between dose and grind setting, the ideal gap between the puck and the shower screen, and other details, and shares practice ideas for brew ratios, helping you consistently recreate a delicious espresso at home.

Why do cafes touch their grinders every single day?

Many cafes reset their grind setting every day, and some shops even have to readjust every few hours. If you're strict enough about extraction results, in theory you should recheck every 5 hours, because the condition of the coffee beans is constantly changing, and air pressure, temperature, and humidity also interfere with extraction. Espresso extraction happens under high pressure, so the effects of these variables get amplified further. That's why knowing how to adjust the grind is an important measure of a barista's fundamental skills.

What exactly is the point of adjusting the grinder

The moisture content and storage time of coffee beans are always changing, and the wear on the grinder burrs accumulates over time. So baristas need to recalibrate the grinder regularly so that the grounds it produces always stay in the ideal state.

After coffee beans fall into the grinder, the burrs crush them into grounds. The narrower the gap between the two burrs, the finer the particles you get. The finer the particles, the denser the coffee bed, the greater the resistance water encounters passing through, and the longer the extraction time is stretched out. Conversely, widen the burr gap, the particles become coarser, water passes through more easily, and extraction speeds up naturally. You can use rocks and fine sand as an analogy: water flows through rocks far faster than through fine sand, because the gaps left between rocks are larger. From this you can see that getting the grind right is crucial — particle size directly determines extraction quality.

How to tell whether the grounds are up to standard

By feeling or observing the coffee grounds: the ideal grounds should be powdery while also having a gritty, sandy texture. If they feel soft, close to the texture of flour, they're ground too fine; if they feel coarse, hard, and prickly, they're ground too coarse.

Grinder adjustment tutorial

The adjustment dial design differs from brand to brand, so first confirm your model and read the manual carefully to understand the dial's direction of rotation and range of adjustment. Generally speaking, as long as you habitually check the grinder settings regularly, each adjustment only needs to be extremely small. A dial movement of no more than 3 millimeters is enough to change the coarseness of the grounds. Don't underestimate 3 millimeters — the grinding time for the same batch of beans can differ by 3 to 5 seconds because of it.

Specific operating steps

First determine which direction you need to adjust (finer or coarser). Confirm the hopper is filled with enough coffee beans, and check that the valve between the hopper and the burrs is open, so the beans can flow smoothly into the grinding chamber.

Start the grinder and let it run empty for 10 seconds, then discard the grounds that come out (the grind setting for these hasn't been dialed in yet).

Use the freshly ground coffee to make a shot, making sure the dose, distribution and leveling, and tamping are all accurate. A traditional Ristretto uses a brew ratio of 1:1 (18 grams of coffee extracting 18 grams of liquid) or 1:2 (18 grams of coffee extracting 36 grams of liquid), while a standard Normale espresso uses a brew ratio of 1:2.

Taste the coffee quality and record the extraction time. Make repeated fine adjustments to the dial until the coarseness of the grounds reaches the ideal state.

How to adjust an electronic grinder

An electronic grinder mainly involves two variables: dose and grind setting. The two constrain each other — change one, and the other changes along with it.

A standard electronic grinder regulates grinding and dosing time based on a preset dose (note: the grinder controls dose by time, not by weight). If you're unhappy with what's in the cup, first figure out whether the problem lies in the dose or the grind setting.

Normally, after an accurate dose, leveling, and tamping, there should be a 5 to 6 millimeter gap between the surface of the puck and the shower screen. If the puck height deviates from this range, it's time to adjust the dose (that is, the grinding and dosing time). Each time you adjust the dose, keep the change between 0.2 and 0.3 seconds, and recheck the coffee quality after every adjustment.

The hardest part of adjusting an electronic grinder is this: when you change the grind parameter, the burr gap changes accordingly, and the burr gap directly affects the dose — that is, the grinding and dosing time. If you want to grind finer, the burr gap narrows, and fewer beans pass through the burrs in the same amount of time; conversely, widen the burr gap, and more beans pass through per unit of time.

Therefore, before adjusting an electronic grinder, you should first clarify the relationship between dose and grind setting. These two variables move together when either one changes, and you need repeated testing and constant correction to find the best combination.

Any tiny change on the grinder will have a noticeable impact on the coffee's overall performance. So baristas should re-measure and adjust the grinder every day to ensure consistent output.

To master brew ratios, you can fix the coffee dose during practice (say, 18 grams), then pair it with different total liquid weights, and compare how various ratios differ in mouthfeel, clarity, and body. The final brew ratio still comes down to personal preference.

Only through repeated practice and constant exploration can you make an espresso that truly suits your own taste.

Actually, in making espresso, besides controlling all the parameters well, Front Street believes that choosing the right coffee beans is equally key — after all, the beans are the fundamental factor determining whether the coffee tastes good.

If you want to make cafe-style espresso at home, we recommend trying Front Street's classic espresso blend. This coffee is blended from three origins — Brazil, Indonesia, and Vietnam — combining the caramel sweetness of American coffees with the wild character of Asian coffees. To maximize the coffee's rich aroma and to let everyone easily extract a thick, creamy crema, Front Street Coffee uses a deep roast. Whether you're making an Americano diluted with water or a latte paired with milk, it's a great fit. You can place an order at the Front Street Taobao store or the Front Street Tmall flagship store.

The above content is compiled by CoffeeHunters, a coffee news website.