It's True, Many British Beers Actually Rely On Fish Bladders To Get The Finished Product - Tasting Table

"Fish and beer have a longstanding relationship. Beer-battered fish, fish and chips with a frosted pint; these combos are popular and a crowd favorite. But there's another collaboration between fish and beer that most people are unaware of - unless they know to look for it. We're talking about isinglass (or fish bladder), and no, you can't taste it in your ale. However, small traces of it are probably in your glass, depending on the brewery, and it's largely the reason for your beer's crisp, cloudless appearance."

"For hundreds of years, isinglass has been used as a clarifying agent for not just beer, but also natural wines, hard cider, and other alcoholic beverages. In the fermentation process of beer, yeast and other particles are present in the cask, making the alcohol cloudy. While this sediment will settle naturally over time, breweries use isinglass as a "fining" to speed up the settling process. While vegan options now exist, isinglass is still widely used in some locations, including the United Kingdom."

"Isinglass is made from the lining of a fish's swim bladder. The swim bladder is used to control a fish's buoyancy as it changes depths in the water. Once the bladder is harvested, it is dried and cleaned afterward producing a film. The film is then heated so that it forms a sticky substance - a collagen that has ended up as a key ingredient in multiple industries. The isinglass collagen has protective properties and has been used in medical dressings, adhesives, and glues as well as a preservative for art. It's even been used by performers to coat the bottoms of their feet in order to pull off walking on hot coals. In terms of food, isinglass has been used both as a gelatin ingredient and as a preservative that keeps bacteria out and moisture in."

Isinglass is a collagen derived from the lining of fish swim bladders. Breweries use isinglass as a fining agent to speed the settling of yeast and particles, producing clear, crisp beer; it has also been applied to wines, ciders, and other beverages. The swim bladder is dried, cleaned, and heated into a sticky film used across industries. Isinglass collagen has protective properties and has seen use in medical dressings, adhesives, glues, art preservation, and food applications as gelatin or a preservative. Vegan alternatives exist, but isinglass remains widely used in some regions, including the United Kingdom.

Read at Tasting Table