Why are wine bottles 75cl?

Ever wondered why wine bottles aren't a nice round 1 litre? The answer is a delightful piece of trade history.

Before standardisation, wine bottles were hand-blown, and each glassblower produced slightly different sizes — typically between 65 and 80 cl, roughly the volume of air one person could blow in a single breath. So there was a natural tendency toward the 70–75 cl range even before anyone set a rule.

The 75 cl standard crystallised through trade between Bordeaux and England — France's biggest wine export market. The British measured liquids in imperial gallons (4.546 litres), and customs duties were calculated in gallons. A standard Bordeaux barrel (a barrique) holds exactly 225 litres, which is roughly 50 imperial gallons. At 75 cl per bottle, that's exactly 300 bottles per barrel — a beautifully clean number for both French and British accountants.

The European Economic Community made it official in 1977 with Directive 75/106/EEC, and the 75 cl bottle became the legal standard across Europe. Through international trade agreements, it's now the global norm.

There are exceptions: half-bottles (37.5 cl) for solo dining, magnums (1.5 L) for parties and better ageing, and a whole family of large formats with biblical names — Jeroboam (3 L), Methuselah (6 L), Salmanazar (9 L), up to the mighty Nebuchadnezzar (15 L). Dessert wines like Sauternes and Tokaji often come in 50 cl bottles because yields are tiny and the wine is so concentrated that smaller servings are the norm.

Fun fact: magnums aren't just for show. Because the ratio of wine volume to cork surface is more favourable, wine ages more slowly and evenly in magnums — which is why collectors and sommeliers prize them.