Wine bottles are shaped differently mainly for historical and traditional reasons, but there are also some functional and practical reasons. Here are some possible explanations:
Tradition: Certain bottle shapes have become traditional in certain wine regions, such as the Bordeaux bottle used for Bordeaux wines or the Chianti bottle used for Tuscan wines.
Wine Identification: The shape of the bottle can also be used to identify the type of wine it contains. For example, the Bordeaux bottle is generally associated with red wines, while the tall, thin bottle used for Riesling wines often indicates a white wine.
Wine Storage: The shape of the bottle can also affect wine storage. For example, taller, thinner bottle shapes can reduce the amount of oxygen in contact with the wine, which can be beneficial for white and sparkling wines that require less oxidation.
Marketing: some bottle shapes can be chosen for marketing reasons, in order to distinguish the wine on the shelf or to give a high quality or luxury image.
In general, the choice of bottle shape depends on the preferences of the producer, the tradition and the wine region, but also on functional and marketing reasons.