A Carboy is a glass vessel used in fermenting wine, mead and sometimes beer. Usually it is fitted with a rubber stopper and an airlock to prevent bacteria from entering during the fermentation process.

Carboys come in various volumes ranging from 1 gallon to 6.5 gallons. A 15 gallon carboy is often called a demi-john.

This article is a stub. You can help Wikipedia by fixing it.