A magnum is not simply a larger bottle. It ages more slowly and more gracefully than a 750ml — the ratio of wine to oxygen exposure through the cork is lower, which means the wine develops over a longer arc and arrives at its peak in better condition. For wines that are made to age — Grand Cru Burgundy, serious grower Champagne — the magnum is the optimal format. The investment in the bottle is repaid in the glass, sometimes ten or fifteen years later.
