The Craft Beer Channel visits AB Vickers to learn all about isinglass finings 

Lallemand Brewing welcomed Jonny Garrett from The Craft Beer Channel to our Burton Upon Trent, U.K., location to learn more about the history of isinglass and its role in the production of traditional cask ale. 

Isinglass is often considered to be the fifth ingredient in producing high-quality cask ale. With its 200-year history as a supplier to the brewing industry, AB Vickers was a natural fit to be part of the follow-up season to the channel’s Keep Cask Alive documentary series. During the series, the channel visited breweries, pubs, festivals, factories, and farms to tell stories of cask beers history and future. 

A brief history of isinglass 

The use of isinglass in the UK beer industry has been documented for centuries. However, it is believed that in ancient Egypt, thousands of years ago, wine and beer stored in the swim bladders of fish were known to become clearer. From the 1850s, isinglass production became an important industry in the UK as beer production increased, explains Brent Jordan, President and General Manager of Lallemand Brewing. Of course, today’s isinglass production methods are far more refined than back then. 

“There’s an old saying that you drink with your eyes. Clarity has historically been considered as one of the first indicators of good quality beer, particularly where traditional cask beers are concerned. That was probably the reason that isinglass became such a big part of the brewing industry. People expected beer to be clear,” Brent says during the interview. “It is still an artisan industry – there remains a great deal of skill involved in producing high-quality isinglass.” 

Isinglass processing 

Isinglass production begins with the sourcing of maws, or swim bladders, of certain species of fish. Dried maws are imported into the UK directly by AB Vickers in a clean, dry form. These maws are, essentially, a by-product of the village fishing industries of South East Asia, and provide a source of income for these local fishing communities. The maws are typically comprised of around 98% collagen, the “active material”.  The isinglass production process requires chopping, sterilizing and further processing into highly refined, purified forms of either liquid or dry product. Temperature control is critical throughout the process, since high temperatures can degrade isinglass. The U.K. brewing industry primarily uses liquid isinglass products, whereas overseas markets use a dry form which is liquified at point of use. 

How isinglass works in brewing 

Isinglass is added to beer at the end of fermentation whereupon it dramatically accelerates the sedimentation of yeast and protein particles to give the typically bright appearance of a cask-conditioned beer or, alternatively, isinglass added to the tank will greatly improve the rate of filtration for brewery conditioned and filtered beers.  

Collagen, the pre-hydrolyzed form of isinglass, exists in solution as a tightly bound triple helix, which, at beer pH possesses both positive and negatively charged sites along its length. The amino acid make-up of collagen, and specifically the high proportion of proline and hydroxyproline residues, contribute to its remarkable ability to remove both yeasts and protein so effectively. In a typical application, greater than 95% of yeast and 90% of proteins are removed. 

“What you’re trying to remove in cask beer is yeast and protein to make beer bright,” explains Sarah Young, Global Product Manager, AB Vickers. “Isinglass contains collagen which, once hydrolyzed and added to beer, exhibits a positive charge whereas yeast has a negative charge. Isinglass attracts both the yeast and proteins with the resulting large particles settling out rapidly. Isinglass functionally removes the yeast. It’s perfect for cask beer!” 

Sarah also discusses alternatives to isinglass that have been tried over the years. However, the unique properties of Isinglass — combined with the rich history and tradition in brewing — make the product irreplaceable in traditional cask ale production. 

“Before going to Burton, I had a completely different perspective on isinglass,” Garrett notes. “I saw it as an old practice, bound to change with the times once breweries trusted other methods enough. But, from both a technical perspective, it is incredible at clearing beer, and from a historical one, with the remarkable story and tradition that comes with it, I’m now glad many breweries have stuck with isinglass and will likely do so for a long time.” 

See isinglass production in action at AB Vickers!