How to Dial In Your Espresso Grind Size

Dialing in is the process of adjusting your grinder until your shots run correctly. It's the most important skill in home espresso, and it's more straightforward than it sounds once you understand what you're actually adjusting.

Grind size controls how fast water moves through the puck. Too coarse and the shot runs fast and tastes sour. Too fine and it chokes the machine or tastes harsh and dry. Everything else matters too (dose, distribution, tamping), but grind size is the primary variable you're solving for.

Lock Your Dose First

Before touching the grind setting, lock in your dose. Pick a number (18 grams is a common starting point for a 58mm double basket) and use a scale to hit it consistently. Even a half-gram difference changes how shots pull, so eyeballing won't work here. The goal is to eliminate every variable you can so that grind size becomes the only thing you're adjusting.

This is the approach our team uses: dose is a variable you can nail down and hold constant. Grind size is the trickier one because it's different for every bag of coffee. Solve dose first, then work grind.

How to Adjust Grind Size

Start coarser than you think you need to. A shot that's too coarse runs fast and tastes sour. That's diagnosable. A shot that's too fine can choke the machine entirely, which is harder to recover from on the first try. Find the fast/sour zone first, then work finer from there.

Make one adjustment at a time. On a stepped grinder, that means one or two steps. On a stepless grinder, small turns. Pull a shot after each change and evaluate before adjusting again. The most common mistake is changing the grind multiple steps at once and then not knowing which change produced which result.

After adjusting, grind through a small amount of coffee and discard it before pulling your evaluation shot. This purges the old grind setting from the burrs so you're actually tasting the new setting, not a mix of both.

Reading the Shot

Use a scale to weigh your yield. For a standard 1:2 ratio starting with 18 grams, you're targeting 36 grams out. Aim for that yield to arrive in 25 to 35 seconds. Under 20 seconds is too fast. Grind finer. Over 40 seconds, or a shot that barely drips, means it's too fine. Go coarser.

Time and weight tell you the mechanics. Taste tells you the truth. A sour, thin shot is under-extracted and needs a finer grind or longer yield. A bitter, dry, harsh shot is over-extracted and needs a coarser grind. A good shot tastes sweet with a finish that lingers. When the sourness and sweetness are in balance, you're close.

Stepped vs Stepless Grinders

Stepped grinders have fixed positions on the dial. Most home grinders are stepped. They're easier to work with when you're starting out because you can reference a specific number and return to it reliably. The downside is that the sweet spot for a particular coffee sometimes falls between two steps.

Stepless grinders adjust continuously like a screw, which gives you finer control but requires more feel to use well. They're the standard on most dedicated espresso grinders at the mid and upper end of the market, and worth it once you're past the early learning curve. Browse our espresso grinders to see what's available at different price points.

When to Dial In Again

Every time you open a new bag. As a bag ages, beans lose CO2 and become more soluble, which means shots will progressively run faster as the days go on. A grind that's dialed in on day three of a bag may be too coarse by day ten. Humidity shifts can also affect grind behavior, particularly in seasonal transitions. When shots start running noticeably faster or slower without a deliberate change on your part, the grind needs attention. A quick note of your grind setting, dose, and yield when you dial in gives you a reference point to find your way back quickly.