Name That Bottle!
Let’s start with the standard-size wine bottle, at 750ml. If you split that in half, to 375ml, you’ll end up with a “split,” “half-bottle” or “demi.” But you were asking about larger formats. A “magnum” is 1.5 liters, or the equivalent of two bottles, and if you double that, you’d have a “double magnum,” at 3 liters. (A 3-liter bottle is also known as a “jeroboam” in Champagne and Burgundy, but in Bordeaux, a jeroboam is 4.5 liters.)
Things get bigger faster after that: a 6-liter bottle is called either an “imperial” or a “methuselah,” a “salmanazar” holds 9 liters (as much wine as a full case of standard bottles), a “balthazar” holds 12 liters and a “nebuchadnezzar” holds 15 liters.
While it’s pretty easy to find magnums, the larger-format bottles are more rare, usually available only at auctions. As you might imagine, large bottles are considered collectibles because of their rarity, and because conventional wisdom holds that the wine in these bottles ages more slowly than their smaller counterparts.