Medium — about the consistency of coarse sand or fine sea salt. The coffee should finish brewing in 2.5–4 minutes. Go slightly finer for a V60, and slightly coarser for a Chemex. Too fine gets bitter, too coarse gets watery.

What grind size do I need for filter coffee?

Medium — about the consistency of coarse sand or fine sea salt. The coffee should finish brewing in 2.5–4 minutes. Go slightly finer for a V60, and slightly coarser for a Chemex. Too fine gets bitter, too coarse gets watery.

Why this is the case

Filter coffee relies on gravity rather than pressure. Hot water flows down through the coffee grounds and the paper filter — and the contact time dictates how much flavor is extracted from the coffee. The grind size is the primary way you regulate this contact time: Finer grind = slower flow rate = longer extraction. Coarser grind = faster flow rate = shorter extraction.

The ideal range is a medium grind size. For comparison: think of coarse sand, fine sea salt, or the texture of semolina. If you rub the grounds between your fingers, you should feel the individual particles — it shouldn’t clump together like espresso, nor should it feel like large, chunky breadcrumbs.

Within this medium range, there are slight adjustments depending on your exact brewing method:

V60 and Kalita Wave: Slightly finer than the dead center. The target brew time is usually 2:30–3:30 minutes for a single cup. The thin paper filter of the V60 lets water pass through more quickly than thicker filters do, so you need slightly finer grounds to provide enough resistance and contact time.

Chemex: Slightly coarser. The very thick Chemex filter inherently slows down the water flow. Because of this, you need a coarser grind to prevent the water from stalling and over-extracting the coffee. Target brew time: 3:30–4:30 minutes.

Drip Coffee Machine: Standard medium grind. The machine dictates the water volume and delivery speed, so you adjust the grind size to match that flow. Most standard machines are calibrated for a 4–6 minute brew cycle for a full pot.

Your most important tool alongside your grinder is a timer. If the coffee flows through too fast (under 2 minutes for a single cup), it will taste weak and sour — adjust your grind finer. If it flows too slowly (over 4:30 minutes), it will taste harsh and bitter — adjust your grind coarser. Always make small adjustments and only change one variable at a time.

In practice at Green Wall Coffee

For our hand-brewed filter coffee at Sophienstraße 27, we use the Hario V60 and grind slightly finer than the standard medium baseline. Using 15 g of coffee to 250 ml of water, we aim for a total brew time of around 3 minutes. For guests making filter coffee at home, I recommend this starting point: sea salt consistency, a ratio of 60 g of coffee per liter of water, and then fine-tune the grind size based on your brew time and taste.

Related questions

• What grind size do I need for espresso?
• What grind size do I need for French press?
• Why should you grind coffee fresh?

For more depth on the subject, check out our V60 pour-over guide. Or visit us at Sophienstraße 27 — Mon–Fri 8am–5pm, Sat 10am–5pm.