Properties2
| Type | Concept |
| Note created | Feb 15, 2026 |
Lactic acid processing is a coffee fermentation method where ripe, high-sugar cherries are placed in sealed anaerobic tanks to create ideal conditions for lactobacillus cultures — the same bacteria used in dairy production. Without oxygen, these bacteria dominate the fermentation, converting the sugars in the mucilage into lactic acid, ethanol, and CO₂ over a minimum of ~80 hours. Producers carefully monitor pH, temperature, and moisture throughout. The process is risky: long fermentation times can lead to phenol development, fungus, or over-fermentation that results in overwhelming bitterness. High-altitude cherries are preferred for their higher mucilage content.
When executed well, lactic-processed coffees have a very sweet cup with medium-high body, strong lactic acidity, and tropical fruit flavours — often recalling papaya or pineapple yogurt. Pioneers of the method include La Palma y El Tucan in Colombia, who developed it through extensive experimentation at their wet mill.