Grind size is arguably one of the most crucial variables in coffee brewing, yet it's often overlooked by beginners. The size of your coffee grounds directly impacts how water interacts with the coffee, which in turn determines the flavor and strength of your final cup.

Why Does Grind Size Matter?

Think of coffee grounds as tiny sponges. When hot water passes through or steeps with them, it extracts flavor compounds, oils, and acids.

• Finer Grind: More surface area is exposed to the water. This means extraction happens faster. If the grind is too fine for your brew method, water will extract too much, leading to over-extraction. Over-extracted coffee often tastes bitter, harsh, and hollow.
• Coarser Grind: Less surface area is exposed. Extraction happens slower. If the grind is too coarse, water won't extract enough, resulting in under-extraction. Under-extracted coffee typically tastes sour, weak, acidic (in a bad way), and lacking sweetness or body.

General Grind Size Recommendations by Brew Method:

• Extra Coarse (like peppercorns): Cold Brew
• Coarse (like breadcrumbs): French Press, Percolators
• Medium-Coarse (like coarse sand): Chemex, Clever Dripper, Cafe Solo Brewer
• Medium (like regular sand): Drip Brewers (e.g., Bonavita, Technivorm), Siphon Brewers, AeroPress (for longer steep times)
• Medium-Fine (like table salt): Cone-shaped Pour Overs (e.g., Hario V60, Kalita Wave), AeroPress (for shorter steep times)
• Fine (finer than table salt, slightly coarser than flour): Espresso, Moka Pot (Stovetop Espresso)
• Extra Fine (like flour/powdered sugar): Turkish Coffee

Dialing In Your Grind:

The recommendations above are starting points. You'll need to "dial in" your grind based on your specific coffee beans, grinder, and taste preferences.

• If your coffee tastes sour or weak: Try a finer grind.
• If your coffee tastes bitter or harsh: Try a coarser grind.

Make small adjustments, one variable at a time, and taste the results. Keeping notes can be very helpful. A good quality burr grinder is essential for consistency, as blade grinders produce uneven particle sizes.