Time, temperature, pH monitoring
This topic explains how monitoring time, temperature, and pH during washed coffee fermentation ensures consistent quality, prevents defects, and enhances flavor outcomes.
- Coffee Basics Nerds
- 2 min read
Article 4 of 12 in Wet Processing (Washed) Details/
Why Monitoring Matters
- Fermentation is a biological process influenced by multiple variables.
- Without monitoring, risk of over-fermentation or under-fermentation increases.
- Tracking time, temperature, and pH provides control and consistency in processing.
Time
- Typical range: 12–72 hours depending on climate and method.
- Short fermentation (cool climates): Slower microbial activity → extended times.
- Long fermentation (hot climates): Faster breakdown, risk of sour/over-fermentation if unchecked.
- Best practice: Check regularly, not just at fixed intervals.
Temperature
- Impact: Higher temperatures accelerate microbial activity, shortening safe fermentation windows.
- Optimal range: 15–30°C (59–86°F).
- Above 30°C: Risk of excessive acid production and off-flavors.
- Below 15°C: Fermentation may stall or take too long.
- Shade, water management, and tank design help regulate temperature.
pH Monitoring
- pH is a reliable indicator of fermentation progress.
- Freshly pulped beans: pH ~6.0.
- Properly fermented beans: pH ~4.2–4.5.
- Below pH 4.0: Over-fermentation → sour, vinegary notes.
- Monitoring with handheld pH meters provides accuracy.
Practical Monitoring Routine
- Record start time when beans enter tanks.
- Check temperature and pH at intervals (every 6–12 hours).
- Assess mucilage by rubbing beans—should feel non-sticky at endpoint.
- Log data for future consistency.
Benefits of Monitoring
- Reduces risk of inconsistent lots.
- Ensures clarity, acidity, and sweetness are preserved.
- Helps adapt fermentation times to yearly climate variation.
- Provides traceability and proof of best practices for buyers.
Lasting Importance
Monitoring time, temperature, and pH transforms fermentation from guesswork into a controlled, scientific process. By doing so, producers can deliver consistent, high-quality coffee, protect against defects, and build trust in specialty markets.