Among today’s beer drinkers it’s widely accepted that beer now comes in a range of opacities. From sparklingly clear to relentlessly turbid, there’s a level of haze to suit almost everyone’s taste.

Much of the beer we drink in the modern era is naturally cloudy, or hazy in appearance. This has been widely accepted for some time in some traditional styles, such as German Hefeweizen and Belgian Witbier but is now also associated with contemporary styles such as New England IPA. The opacity of these hop-heavy recipes is typically due to the abundant use of protein-rich grains like wheat and oats, which create a softer mouthfeel but the beer is hazier because of this. But this is also because many of these beers are “unfined” — meaning the process of “fining” or clearing the beer of sediment is skipped, due to the haze actually being desirable.

For some beer lovers, however, only a perfectly clear beer will do. For them, clarity is a mark of quality; proof to the beholder of said beer that the utmost care has been taken in its production. This is especially true in certain beer styles such as lager, and (although it should perhaps go without saying) real ale conditioned in, and served from a cask.

Among today’s beer drinkers it’s widely accepted that beer now comes in a range of opacities. From sparklingly clear to relentlessly turbid, there’s a level of haze to suit almost everyone’s taste.

Much of the beer we drink in the modern era is naturally cloudy, or hazy in appearance. This has been widely accepted for some time in some traditional styles, such as German Hefeweizen and Belgian Witbier but is now also associated with contemporary styles such as New England IPA. The opacity of these hop-heavy recipes is typically due to the abundant use of protein-rich grains like wheat and oats, which create a softer mouthfeel but the beer is hazier because of this. But this is also because many of these beers are “unfined” — meaning the process of “fining” or clearing the beer of sediment is skipped, due to the haze actually being desirable.

For some beer lovers, however, only a perfectly clear beer will do. For them, clarity is a mark of quality; proof to the beholder of said beer that the utmost care has been taken in its production. This is especially true in certain beer styles such as lager, and (although it should perhaps go without saying) real ale conditioned in, and served from a cask.

Reducing production time is important to breweries in terms of turnover speed. Being able to produce beer more quickly enables them to keep the cost of the beer lower, and ensure its production is profitable. Although not as exciting as, say, hops or malt, finings are a key element of beer production and are not without their own set of controversies, as we’ll explore in this piece.

In brewing, finings can be added at various stages of the process to help achieve the desired level of clarity. “Kettle finings” are typically added during the boil to help settle the proteins naturally present in grains such as barley, wheat and oats. Otherwise finings are either added to a beer towards the end of production, during maturation, conditioning, or during packaging to achieve the desired level of quality.

Notably, in the final production stages of real ale, unlike with other packaging methods, finings are typically added directly to the cask. This is partly due to real ale still undergoing secondary fermentation within the vessel itself, and the very nature of this process creates carbon dioxide that will cause any particulate still present in the beer to be stirred up. Not to mention, casks get moved around a lot, rousing any sediment within them. The finings in the cask will ensure that it’s clear again by the time it reaches your glass.

However, as finings are a process aid rather than an ingredient, the producer does not need to notify the consumer of their use in the same way as it would with say, hops, malt or yeast. This is highly contentious, as some types of finings are derived from animal products, and often means those with vegan, or plant-based diets have little way of knowing if the beer they’re drinking meets their dietary requirements. More on this shortly.

“Finings is a collective noun referring to a group of substances that are used to clarify beer, wine and some other non-alcoholic beverages such as fruit juice.”

— Matt Curtis

They’re Taking the Hobbits to Isinglass

There are many types of finings, including silica-based brands like Protosol, Super F, Brausol, and Protofine, and some that are derived from certain varieties of red seaweed such as Carrageenan, which is more often referred to as “Irish Moss”.

Despite there being a range of fining products available today, the most prevalent type used in brewing is a product derived from fish known as Isinglass. A collagen derived from the swim bladders of fish, historically it was farmed from sturgeon. This was until in the late 18th century when Scottish inventor William Murdoch developed a cheaper way of producing isinglass using cod, or hake. Today’s commercially used isinglass is made from farmed tropical fish.

Wait, there’s fish guts in my beer?

Isinglass is rather unfortunately referred to by some beer drinkers as “fish guts” although this isn’t the most accurate way of describing it. The substance you’ll see going into the cask is a clear liquid that will form into a gelatin-like substance once it has done its job of clearing particulate out of the beer. You don’t actually consume isinglass when you drink a beer in which it’s been used as a fining, and this includes cask ale, as the product remains in the container. It is an animal product however, so beers that use it are not suitable for those with diets that avoid animal products.

It would be easy enough for brewers to switch to silica-based finings, or not use them at all. And the good news is that many don’t! However, isinglass is still popular due to the speed and effectiveness with which it clears a beer, often outperforming alternative fining agents in side-by-side comparisons.

Isinglass remains especially popular in the production of craft beer, as unlike some alternatives it is effective repeatedly. As casks often get moved about a lot before they are finally stillaged in a pub cellar, it’s often the only fining agent some brewers reliably trust to clear the beer before it’s served. As such, if you avoid animal-products, it’s always worth checking at the bar that what you’re drinking is vegan, as beers which use isinglass are not.

Isinglass remains especially popular in the production of craft beer, as unlike some alternatives it is effective repeatedly. As casks often get moved about a lot before they are finally stillaged in a pub cellar, it’s often the only fining agent some brewers reliably trust to clear the beer before it’s served. As such, if you avoid animal-products, it’s always worth checking at the bar that what you’re drinking is vegan, as beers which use isinglass are not.

A Clearer Picture

As mentioned earlier in this article, many brewers are now deliberately choosing to brew hazy beers, which completely eschew the use of finings, including the vegan-unfriendly isinglass.

Some brewers (and drinkers), however, are simply less fussy than they used to be about the need for perfectly clear beer. It’s perfectly normal for a beer to be a little cloudy, especially styles that use a lot of wheat or oats in addition to barley malt. Often now you’ll find that when a beer is not being served “bright” that a good pub will indicate at the point of sale that it’s naturally hazy. Remember though, to always trust your palate. There’s a difference between hazy and faulty, and if it doesn’t taste right always take it back and ask for it to be changed for something else.