Bollinger has released a new bottle with a narrow neck which it says will slow the ageing process and deliver a better wine.

The renowned Champagne producer has reverted back to a bottle that was used in the 1840s, and has released the product at the London International Wine Fair this week.

Compared to the standard bottle, the ratio of neck diameter to base diameter on the 1846 bottle is 26mm to 93mm, as opposed to 29mm to 85mm of the standard bottle.

Bollinger chef de cave Mathieu Kauffmann said: "The idea of using the curved shape of this old bottle was to aim for the perfect balance of a 'small magnum.'" He also said that the bottle is more pleasing to the eye than the standard bottles they use.

"In addition to the aesthetic reasons, using the shape of this new bottle, which is more like a magnum with a narrower neck and a wider base, should very slightly slow down the oxygen exchange and therefore give a better quality wine," Mr Kauffmann added.