“It is part of our ongoing efforts to further improve the way we make our products”
– Guinness spokesman

A spokesman for Guinness said it would begin using a new filtration plant that would be vegan-friendly, having previously used isinglass – a by-product of the fishing industry used to help yeast settle faster.

The new system is due to be installed sometime in 2016.

A Guinness spokesman said: “While isinglass is a very effective means of clarification and has been used for many years, we expect to stop using it as the new filtration asset is introduced.”

First Lady Michelle Obama and President Barack Obama enjoy a pint of GuinnessPhoto: Tim Rooke/REX

First Lady Michelle Obama and President Barack Obama enjoy a pint of Guinness   Photo: Tim Rooke/REX

Isinglass has been used since the 19th Century and while large quantities of the agent are filtered out during the brewing process, there are still traces of fish bladders in the finished product.

The spokesman added: “We are conscious that its use may represent a barrier to consumption of our products to some. As part of our ongoing efforts to further improve the way we make our products, we are seeking alternatives to isinglass.”

The news follows a longstanding campaign and several online petitions from beer-loving vegans, with many highlighting the fact Guinness and other breweries are not required to state the use of isinglass on the bottle.

Guinness is understood to be looking at two filtration methods which would not require isinglass. It is rarely used in modern brewing as synthetic gelatins do the same job of removing excess yeast from the black stuff.

However, some real ale cask beers use isinglass to refine the final brew.