Definition - What does Jeroboam mean?
The Jeroboam is a Bordelaise term for the large format bottles that hold an equivalent of six 750 ml bottles of wine. However, in the regions of Champagne and Burgundy, the bottle is different and is equivalent to a double magnum bottle in Bordeaux, which holds four 750ml bottles of wine.
WineFrog explains Jeroboam
The Jeroboam bottle is named after the High King Jeroboam of Israel who reigned from 922 to 901 BC. Almost all of the large format bottles are named after a historical and prominent king.
The average wine bottle holds 750ml of wine. There are larger formats which exist however. These are often used for high-end wines and/or for special vintages. Some collectors look for them because wines age better and for longer periods in larger bottles.
Not all wines are bottled in larger formats as the glass is expensive and most of these formats have to be filled by hand.