Everything You Need To Know About Isinglass
People who merely drink beer may not give much thought to all the ingredients that go into it. If you brew your own craft beer, however, knowing all the ingredients is essential, especially if you are picky about what goes into it. Not all beer ingredients contribute to the taste or aroma. Some are included to improve the appearance of the brew, and isinglass is one of them.
What Is Isinglass?
Isinglass is derived from the swim bladders of certain fish. The swim bladder is a balloon-like organ that fish use to control their buoyancy. It allows them to swim at a certain depth without expending too much energy in swimming. Isinglass is a thick, colorless solution consisting primarily of collagen that forms when swim bladders are soaked for several weeks in dilute food-grade acids, causing them to dissolve.
What Does It Do to Beer?
During the fermentation process, protein and yeast can build up in beer, causing it to be cloudy in appearance. Isinglass finings may be added to beer to remove this haze by causing the proteins and yeast to sink to the bottom of the barrel. The beer that remains on top maintains a clear, attractive appearance.
How and When Was Isinglass First Used as a Beer Ingredient?
No one knows for sure how people first got the idea to add isinglass finings to beer for clarification purposes, but it probably happened by accident. One theory is that a fisherman and home brewer, perhaps taking inspiration from the practice of using animal skins to store wine, took advantage of a fish's swim bladder as a vessel to hold beer and noticed that it was exceptionally clear when he poured it back out.
Where Does It Come From?
Originally, isinglass was made from the swim bladders of sturgeon. Now it is more often derived from tropical or subtropical fish living in estuaries, which are transitional areas between freshwater and saltwater bodies. Lake Victoria in Africa has been plagued by an invasive species called the Nile Perch, which have been harvested and used to make finings in an attempt to control the spread.
Is Isinglass Necessary to Beer Making?
The presence of isinglass is of concern to beer drinkers who are also strict vegetarians or vegans. With the exception of certain cask ales made in the United Kingdom, many commercially produced beers do not contain isinglass. Instead, a process of filtration and pasteurization is used to remove the haze without the need for added ingredients.
Isinglass use is still common among craft brewers. However, part of the advantage of brewing your own beer is that you get to control what does and does not go into it. If you want to brew a clear beer without the use of isinglass, alternatives containing carrageenan, a polymer chemical, are effective at removing proteins, though less so with yeast. An example of this type of vegetarian fining is a type of red algae known as Irish moss. There is also products like Silafine or Biofine that utilize negatively charged fining agents that bind with positively charged haze active proteins and polyphenols. If you have any questions about beer fining agents, please give us a call or email.