How fine should I grind?
Every coffee lover knows that the grind of your coffee beans has a huge impact on the flavor of your cup. Yet, this is often underestimated. Many people invest in expensive beans and fancy brewing equipment, but forget that the grind is the key to a truly perfect cup of coffee.
In this blog you will discover:
- Why grind size is so important
- How to recognize if your grind is too coarse or too fine
- A complete grind size overview including millimeter values
- Practical tips for experimenting yourself and finding your ideal setting
Why the right grind is so important
The grind size determines how quickly water flows through the coffee and how much flavor is extracted.
Ground too fine : can lead to over-extraction → bitter, astringent taste.
Too coarsely ground : can lead to under-extraction → watery, bland taste.
The goal is to find a balance where the water has just enough contact time with the coffee to achieve optimal flavor.
How do you test if your grind is correct?
A handy barista trick:
1. Try without sugar or milk.
2. Is the coffee too bitter ? Grind it coarser.
3. Is the coffee too acidic or weak ? Grind it finer.
4. Always adjust in small steps (0.1 mm can already make a big difference).
Grind sizes explained (with mm)
Here are the most commonly used coffee grinds, from coarse to fine, including the average particle size in millimeters.
1. Extra fine (0.1 – 0.3 mm)
- Texture: Powdery.
- Brewing method: Turkish coffee.
- Reason: Coffee is not filtered → everything in the cup.
2. Fine (0.3 – 0.5 mm)
- Structure: Table salt.
- Brewing method: Espresso.
- Reason: Short contact time (25–30 sec) but high pressure → full flavour.
3. Medium fine (0.5 – 0.6 mm)
- Structure: Slightly finer than sand.
- Brewing method: Aeropress (short brewing time), Siphon.
- Reason: Faster extraction without over-extraction.
4. Medium (0.6 – 0.8 mm)
- Structure: Fine sand.
- Brewing method: Filter coffee (V60, Kalita Wave).
- Reason: Optimal extraction for 2–4 minutes brewing time.
5. Medium coarse (1 mm)
- Structure: Coarse sand.
- Brewing method: Chemex, Clever Dripper.
- Reason: Provides balance between throughput time and flavor complexity.
6. Coarse (1.0 – 1.5 mm)
- Structure: Coarse sea salt or coarse sand.
- Brewing method: French press, percolator.
- Reason: 4–5 minutes extraction without too much bitterness.
7. Extra coarse (1.5 – 2.0 mm)
- Texture: Large grains, almost like coarse sea salt.
- Brewing method: Cold brew, cowboy coffee.
- Reason: Long extraction time (8–24 hours) requires large particles.
Useful tips for home
- Invest in a good grinder : Always choose a burr grinder instead of blades for more consistent particle size.
- Measure your grind: A simple sliding caliper can help you get really precise.
- Adjust per bean: Dark roasts often require a slightly coarser grind than light roasts.
- Test by brewing method: Brew the same coffee with different grinds and taste the difference.
Conclusion
The perfect cup of coffee starts with the right grind. Whether you want a strong espresso or a smooth cold brew, the grind size (in millimeters) can make the difference between mediocre and great. Experiment with small adjustments, taste, and find your ideal setting.