Grind distribution and fines

Key Concepts

• Particle Size Distribution (PSD):

• Coffee grinds are rarely uniform; PSD charts show the range of particle sizes.

• A narrow distribution produces more even extraction; a wide distribution increases risk of over- or under-extraction.

• Fines:

• Fines are particles significantly smaller than the target size.

• Excessive fines can cause channeling in espresso, clog filters in pour-over, and create bitter or over-extracted flavors.

• Causes of Fines:

• Improper burr sharpness or alignment.

• Too aggressive grinding speed.

• Worn or poorly designed burr geometry.

• Impact on Brew Methods:

• Espresso: highly sensitive to fines; can produce inconsistent shots.

• Drip/Immersion: fines may increase strength but can muddy flavor.

• Mitigation Techniques:

• Adjust grinder settings to reduce excessive fines.

• Use sifting or dosing adjustments to control fines content.

• Regular burr maintenance ensures consistent particle production.

Summary

Managing grind distribution and limiting fines is crucial for achieving consistent extraction, balanced flavor, and reproducible brewing results.

• Tags:
• Key Concepts
• Particle Size
• Ensures Consistent
• Size Distribution
• Highly Sensitive
• Balanced Flavor
• Consistent Extraction
• Brew Methods
• Excessive Fines
• Particle Sizes
• Increases Risk
• Burr Sharpness