After 256-years the Dublin brewers of the famous stout, Guinness, are changing the recipe and refraining from using fish bladders as filters. After years of campaigning by strict vegans and vegetarians it seems the Dublin brewer has finally given in and isinglass will no longer be part of the brewing process.

And there we were thinking it was just barley, hops, yeast and water. Yes, you heard us, there are bits of fish bladder (isinglass) in your pint of plain.

Isinglass is a by-product of the fishing industry and was used by Guinness to remove extra yeast from the stout to help it settle faster. Since the 19th century isinglass has been used in large quantities and there are traces of the fish bladders which remain in the finished product.

According to a Guinness spokesperson the company will begin using a new vegan-friendly filtration plant, when it is completed, in 2016.

They 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.”

The spokesperson continued, “We are conscious that its use may represent a barrier to consumption of our products to some.

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“As part of our ongoing efforts to further improve the way we make our products, we are seeking alternatives to isinglass.”

Vegans and vegetarians had been campaigning about isinglass for years due to the fact that Guinness and other brewers are not required to state their use of the fish product on their bottles. Twelve years ago the European parliament scrapped a plan to force beer makers into highlighting the use of isinglass after brewers lobbied for the exemption. Their argument was that it had been traditionally used in the brewing process with no recorded side effects.

Isinglass was introduced to Guinness in the 1800s. The fish by-product saved the company $9,200 by recovering beer at the bottom of their vats. It is now rarely used in modern brewing as synthetic gelatins do the same jobs.

Guinness reports that it is currently looking into two filtration methods that would not require fish bladders. However, nine months ago, Barnivore, an online vegan beer and wine guide, wrote that there could be no replacement found for the black stuff.

But don’t fret! A spokesperson told the Irish Times, “We are now pleased to have identified a new process and are re-investing in a new, state-of-art filtration system at St James’s Gate, which once in place will remove isinglass from the filtration process.”