Easily identifiable by its appearance, the wine bottle contains centuries of history, where each specificity is the fruit of chance and history.

A history of trade

While the basic unit of measurement for most liquid products is 1 litre, it may have escaped your notice that wine bottles were an exception with their 75-centilitre format. Standardized in the 19th century, this particular format has given rise to many theories. Some say that it is the most suitable for storing wine, while others argue that 75 cl is the ideal size for drinking wine with a meal or for the lung capacity of a glass blower.

However, none of these theories are true. In reality, the 75 cl format was created to facilitate trade between France and Great Britain!
Indeed, in the 19th century, British merchants were the main importers of French wines. At that time we were already using the litre as a unit of measurement, but the English used the imperial gallon. 1 gallon representing 4, 4.54609 litres, the conversation from one measure to another was not obvious.

In addition, Bordeaux wines were transported to the UK in 225 litre barrels (in Burgundy, the barrels are 228 litres). To facilitate negotiations and trade, merchants found a balance that allowed the 225 litre barrel, or 50 gallons, to be divided into 300 75cl bottles. The wine trade is still marked today by these Franco-British exchanges. The proof is in the sale of cases of 6 bottles, equivalent to 1 gallon.

Hollow bottle bottoms: usefulness or simple coquetry?

Another curiosity specific to wine bottles is the hollow bottom and the green colour. If this time trade has nothing to do with the standardisation of bottles, the reason is still historical.

We have to go back to the 4th century, when the manufacture of bottles was not industrialized as it is today, and each bottle was blown by mouth by glass blowers. At that time, their technique could not guarantee a bottle with an absolutely flat bottom. The hollow base of the bottle, known as the "piqûre", ensures the stability of the bottles when they are standing.

Green, a colour that is not due to chance

In order to preserve wine in the best conditions, it is recommended to keep bottles in a cool place and away from light. As wine is sensitive to ultraviolet rays, natural or otherwise, prolonged exposure to light could alter the taste and colour of the wine. This is why most wine bottles are tinted.

But why green? Originally, sand filtering methods were not able to remove all impurities. However, the sand used to make glass is rich in iron impurities, particularly iron oxide. When it comes into contact with very high temperatures, the iron oxide absorbs the red rays, giving the glass its green colour. This defect has become a real advantage in wine conservation.