Guinness To Remove Fish Bladders From Brewing Process

Guinness used a substance called isinglass to help filter its beer — but what was it?

Mnet 50595 Guinness

One of the world's iconic beers is about to tweak its recipe, but it's unlikely that anyone but strict vegetarians will notice much.

Guinness, the classic Irish stout owned by liquor giant Diageo, has used a substance called isinglass to help filter its beer for more than a century.

Many other cask-conditioned beers also use isinglass to cleanse the brew of yeast particles and other unwanted solids.

The gelatin-like substance is removed before the beer reaches the store or tap, but trace amounts do remain.

That posed a marketing problem for Guinness, since isinglass is actually made using the dried swim bladders of fish and prevents the company from labeling its beer as vegetarian-friendly.

Guinness officials said that they worked on an alternative "for some time," and that a new process would be installed at its famed St. James’s Gate brewery in Dublin by the end of 2016.

Although vegan drinkers celebrated the news, the company is keeping quiet about the details of the new "state-of-the-art filtration system."

A report in Popular Science speculated that the brewery would use tactics currently employed by other brewers, including tannic acid or adsorbent agents, to filter its beer in the future.