Runs fermentation far longer than the usual 12-36 hours, often 72 hours or more, chasing deeper fruit notes at the risk of over-fermentation.
Extended fermentation stretches fermentation well beyond the published 12 to 36 hour range for typical washed coffee, commonly to 72 hours and sometimes 96 or 200+ hours. Trade sources say the extra time lets microbes break down pectin and produce more acids and esters, which can mean tropical fruit, berry or dessert-like notes and a heavier body. The same sources warn that over-fermentation can produce harsh, vinegary or phenolic flavors.
How it worksFermentation is deliberately run well past the usual 12-36 hours, to 72 hours or more, giving microbes more time to produce acids and esters.
Our notes on Extended Fermentation are still being checked against their sources, so for now this page shows only the facts we can stand behind.
What can go wrong
- Over-fermentation can bring harsh, vinegary, phenolic or otherwise unpleasant flavors if the ferment is not monitored.
In the cup, according to guides
- FermentedMoreTrade sources describe tropical fruit, candy-like sweetness or berry notes in successful lots, and harsh or vinegary notes in failures.
At the same stage
Sources · 3 Every sentence here was checked against a source we read. Taste notes are what guides describe, not promises about your bag. Last revised 2026-09-30. Some details here are less settled than others.
- Coffee processing · Wikimedia Foundation
- Coffee Fermentation Process: What It Means for the Green Coffee You Buy · Green Coffee Collective
- How Fermentation Changes Coffee Flavor Notes (Anaerobic, Extended, Yeast-Based) · Headcount Coffee