Why grind size changes everything
Have you ever noticed how your coffee can taste completely different from one day to the next — bitter, sour, or flat — even when using good coffee?
In most cases, the problem isn’t the beans or the machine.
It’s the grind size — a small detail that can change everything in just a few minutes.
What is coffee grind size?
Grind size refers to how fine or coarse coffee beans are ground before brewing.
This single variable controls how fast water flows through the coffee and how much flavor is extracted — which is why different brewing methods require different grind sizes.
Why grind size matters across brewing methods
Each brewing method uses:
• different contact time
• different pressure
• different filters
Because of that, the same grind size will not work for every method.
Using the wrong grind size often results in:
• bitterness (over-extraction)
• sourness (under-extraction)
• lack of clarity or balance
Grind size by brewing method
Espresso
Grind size: Fine
Texture: Powdered sugar
Espresso uses high pressure and a short extraction time. A fine grind slows the water enough to extract flavor properly.
Moka italiana
Grind size: Medium-fine (similar to industrial ground coffee)
Texture: Fine sand
Moka requires less resistance than espresso, but more than pour over. Grinding too fine often leads to bitterness.
AeroPress
Grind size: Medium to medium-fine
Texture: Fine sand
AeroPress is flexible and forgiving. Grind size can be adjusted depending on the recipe, but medium-fine is a reliable starting point.
V60
Grind size: Medium
Texture: Sand
Pour over methods like V60 rely on a steady flow. A medium grind helps maintain balance and clarity.
Origami
Grind size: Medium
Texture: Sand
Origami allows more control over flow rate. A medium grind is the best starting point and can be adjusted based on filters and technique.
French press
Grind size: Coarse
Texture: Sea salt
With long contact time and immersion brewing, a coarse grind prevents over-extraction and keeps the cup clean.
One important detail: consistency
More than choosing fine or coarse, consistency is what truly impacts flavor.
An uneven grind creates:
• bitter flavors from over-extracted fines
• sour notes from under-extracted larger particles
This is why a good grinder is one of the most important tools in coffee.
Final thought
Great coffee isn’t about complexity.
It’s about understanding the basics — and grind size is one of the most powerful ones.
— Coffee basics by Yuki ☕🐻
If you want to go deeper, here’s how grind size affects espresso extraction specifically.