Secondary fermentation is a process commonly associated with
winemaking, which entails a second period of
fermentation in a different vessel than the one used to start the fermentation process. An example of this is starting fermentation in a
carboy or stainless steel tank and then moving it over to
oak barrels. Rather than being a separate, second fermentation, this is most often one single fermentation period that is conducted in multiple vessels. However, the term does also apply to procedures that could be described as a second and distinct fermentation period.