The carboy is the classic fermenter used by many American homebrewers (for beer, mead, cider etc ...) in pet food barrel, allows you to decant the must after the tumultuous part of fermentation with lower risk of oxidation and is recommended even after the first transfer for the lagering phase.

Very used in the United States, it needs a siphon to proceed with the bottling phase.

Also useful for those who want to make small batches or for those who produce sour beers.