This story is over 5 years old.


Guinness Is Ditching a Gross Secret Ingredient and Going Vegan

Guinness’s brewing process has long involved the use of fish bladders, which play a role in the filtration process of the beer. But herbivores, rejoice: Guinness is going vegan.

Guinness has had a good thing going for more than 250 years, but there is one consumer base that the Irish stout hasn't tapped: die-hard vegans and vegetarians.

Our apologies if this is unwelcome news, but Guinness's brewing process has long involved the use of fish bladders, which play a role in the filtration process of the beer. But herbivores rejoice: Guinness is going vegan.

READ: There's Blood and Bladders in Your Wine


During the Guinness filtration process, a gelatinous substance known as isinglass is used to clarify the beer. Isinglass is made from fish air-bladders, which allow fish to control their buoyancy as they swim. When isinglass is placed in beer, it attracts yeast sediment and other undesirable particles that give beer a hazy look. The isinglass and impurities then fall to the bottom of the vat, where they are removed from the beer. The isinglass speeds up the settling of these impurities in a process called "fining."

The Smithsonian takes a close look at the origins and use of isinglass, and explains that Guinness has been using it as a clarifying agent since the middle of the 19th century. Today, with modern filtration methods, most beers don't use isinglass. There are exceptions, however, such as British real ale cask beers, which might use isinglass, gelatin, or other animal-based substances to fine filter beer.

Guinness has said that its beer is free from animal matter, but admits it is possible that minute quantities of isinglass might carry over into the finished product. Isinglass doesn't affect the taste or texture of the beer, and beer companies aren't required to state whether a beer includes isinglass as there are no known side effects.

A number of petitions have called for Guinness to stop using the fish-based filtering, and Guinness will be heeding their call when they revamp their St James' Gate brewery next year, switching over to a new, as-yet-unnamed filtering process.


"Whilst 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," a Guinness spokesperson told The Times.

The switch is welcome news to the many vegans and vegetarians who, to steer clear of unwanted traces of animal products, have often turned to beers produced under German and Belgian beer purity laws, which require that beer include only water, grain, hops, and yeast.

READ: Welcome to the Vegan Paradise of Booze and Chili Cheese Fries

Due to lax labeling laws that differ around the world, knowing what's in a beer—or any alcoholic drink, for that matter—can be a bit of a challenge. Alcohol producers aren't legally required to include nutritional information on labels, though industry groups like the Brewers of Europe have voluntarily committed to including nutritional information and ingredients lists on bottle. Diageo, the parent company of Guinness that also owns Johnny Walker, Smirnoff, and Captain Morgan, announced it would voluntarily include nutritional information on some of its labels last March. Diageo currently lists nutritional information and ingredients on its website DRINKiQ website, which does not list isinglass as an ingredient.

But soon, vegans will be able to join the rest of us in throwing back Guinness en masse.

More than 10 million pints of Guinness are sold each day around the globe, with a total of nearly 1.9 billion drained a year. A fish-free Guinness could appeal to the estimated 375 million vegetarians worldwide. If, as they say, Guinness is good for you, then bladder-free beer could be good for business.