Glossary
Biotransformation
Yeast enzymes converting hop-derived compounds into different, often more aromatic ones when hops are added during active fermentation.
The full record
Biotransformation has its own catalogue entry with the detail this page summarises — causes, thresholds, related styles and evidence.
Biotransformation — Add hops during active fermentation so yeast enzymes convert bound hop compounds into aromas the hop could not release on its own.
Yeast can release bound aroma compounds from hop glycosides and convert some terpenes into others, which is why a dry hop added during fermentation can smell noticeably different from the same hops added after it.
The effect is real and reproducible, but it is also frequently overstated in brewing marketing. It shifts a hop’s expression; it does not turn one variety into another.
Related
- Dry hopping — The technique it modifies.
More vocabulary
Arrested fermentation · Barrel ageing · Batch sparging · Blending · Bottle conditioning · Bottom fermentation · Burtonisation · Cask conditioning · Centrifugation · Cold break
See every term on the glossary index.
Last reviewed 2026-08-16.