fermentation mode
Spontaneous fermentation
Fermentation by ambient microflora rather than pitched culture, traditionally via an open coolship, then years in wood.
The full record
Spontaneous fermentation has its own catalogue entry with the detail this page summarises — mechanism, temperatures and what goes wrong.
Spontaneous fermentation — Allow ambient microorganisms to inoculate cooling wort rather than pitching a culture, producing lambic and its derivatives.
Wort is cooled overnight in a broad shallow vessel open to the air, allowing whatever is present in the environment to inoculate it. Which organisms arrive depends on season, which is why lambic production is confined to cool months.
It is the oldest fermentation method and the least controllable. The Pajottenland is the only place where it survived continuously into the modern era.
Used in
- Lambic
Spontaneously fermented Belgian wheat beer, matured in oak for years — funky, acidic, dry and unlike any other beer.
- Gueuze
A blend of young and old lambic, refermented in bottle — intensely complex, bone dry and Champagne-like in its carbonation.
- Fruit lambic
Lambic refermented on whole fruit — traditionally sour cherry or raspberry — producing a dry, tart, intensely fruity beer.