Espresso Grind Size: How to Dial In Perfect Shots Every Time

Grind size is the primary variable you adjust to control espresso extraction. Too fine and the shot chokes (overextracted, bitter). Too coarse and it gushes (underextracted, sour). Dialing in is the process of finding the sweet spot.

The Target Parameters

For a standard 18g dose in a double basket:

• Yield: 36g out (1:2 ratio)
• Time: 25-35 seconds
• Appearance: Honey-like flow, steady stream

The Dial-In Process

Step 1: Start With a Baseline

Set your grinder to a medium-fine setting. Pull a shot and measure time and yield.

Step 2: Evaluate and Adjust

Shot runs too fast (under 20 seconds, gushing):

• Diagnosis: Grind too coarse, water passes through too easily
• Fix: Grind finer (smaller number or tighter adjustment)

Shot runs too slow (over 40 seconds, dripping):

• Diagnosis: Grind too fine, water cannot push through
• Fix: Grind coarser (larger number or looser adjustment)

Step 3: Taste and Fine-Tune

Once you hit the 25-35 second range:

• Sour, thin, sharp: Still slightly underextracted. Grind one click finer.
• Bitter, ashy, dry finish: Overextracted. Grind one click coarser.
• Sweet, balanced, clean aftertaste: You are dialed in.

Daily Adjustments

Grind settings are not permanent. You will need to adjust:

• When opening a new bag of beans
• As beans age (older beans need finer grinding)
• When humidity changes significantly
• When switching between different coffees

Keep a log of your grind settings for each coffee. This speeds up the dial-in process with familiar beans.

The Most Common Mistake

Changing multiple variables at once. Adjust grind size only — keep dose, yield ratio, and distribution constant. One variable at a time is the only way to understand what each change does.