Acceptance thresholds and tolerances
How to set clear quality thresholds and tolerances to ensure consistency in coffee production and brewing.
- Coffee Basics Nerds
- 1 min read
Article 9 of 12 in Measurement & Quality Control/
Acceptance Thresholds
- Definition: Minimum standards a coffee must meet to be considered acceptable for use.
- Examples:
- Cupping score ≥ 80 for specialty-grade.
- Extraction yield (EY) between 18–22%.
- TDS within recipe target (e.g., 1.3–1.5% for filter).
- Moisture content for green coffee between 10–12%.
Tolerances
- Definition: Acceptable range of variation around the target.
- Examples:
- Roast color: ± 3 Agtron points from profile.
- Brew time: ± 5 seconds for espresso shots.
- Dose: ± 0.2 g variation allowed per basket.
Why They Matter
- Prevents inconsistency in flavor, strength, and customer experience.
- Enables faster troubleshooting when defects occur.
- Protects brand reputation by defining clear quality limits.
Implementation
- Define thresholds for each stage: green coffee, roasting, grinding, brewing.
- Train staff to measure and compare results against tolerances.
- Reject or reprocess batches outside thresholds.
Summary
Setting acceptance thresholds and tolerances creates a measurable framework for consistent quality control, ensuring every batch and cup meets professional and customer expectations.