Whirlfloc VS Irish Moss – Beer Fining Agents

How to choose between Whirlfloc and Irish Moss? Which one should I use?

Whirlfloc and Irish Moss are two types of finings agents used in brewing. They both remove proteins from wort (unfermented beer) during clarification. But they differ in their properties and applications.

Whirlfloc vs Irish Moss - Beer Fining Agents

Both finings agents are commonly used in brewing. The choice depends on the type of beer being brewed and the desired clarity level.

The difference between Whirlfloc and Irish Moss is that Whirlfloc is a polysaccharide while Irish Moss is an organic compound derived from red seaweed.

What Is Whirlfloc?

Whirlfloc is a synthetic polymer with high molecular weight. It’s made up of glucose units linked together by ether bonds.

It can be dissolved in water, but it will precipitate out of the solution when exposed to alcohol or other solvents. This property makes it useful for clarifying beer.

How Does Whirlfloc Work?

When added to the beer, Whirlfloc binds to protein molecules in the beer, causing them to aggregate into large particles. These particles float to the top of the beer where they settle out.

As the beer settles, the clear liquid below becomes more concentrated. This allows you to see through the beer and determine its clarity.

Whirlfloc is effective at removing haze-forming proteins such as beta-glucans and tannins. However, it doesn’t remove haze-producing hop oils.

Why Do We Need Whirlfloc?

If you want your beer to have a bright appearance, then you don’t need to add any fining agent.

However, if you want your beer to look crystal clear, then you’ll need to add something to clarify it.

Some beers are naturally cloudy because of yeast cells floating around in the beer. If this happens, there’s no need to add anything to clarify the beer.

However, some beers become cloudier after fermentation due to the presence of proteins. When these proteins come out of suspension, they form a haze which looks like fog.

This is why we need to add a fining agent.

What Is Irish Moss?

Irish Moss

Irish moss is an organic material extracted from the red algae species Ascophyllum nodosum. It contains natural compounds called alginates which help bind suspended matter in the beer.
Alginates also make the beer foam better.

How Does Irish Moss Work?

Like all other finings agents, Irish Moss works by binding to the proteins in the beer. As the proteins bond to the alginate, they clump together forming larger particles.

These particles rise to the surface of the beer where they fall out.

Because the particles are bigger than yeast cells, they won’t interfere with the yeast cell growth process.

Why Do We Need Irish Moss?

Unlike most other finings agents, the addition of Irish Moss does not affect the taste of the beer.

It only removes unwanted proteins so that the beer has a clearer appearance.

There are many brands of Irish Moss available. Some are sold as dry powder while others come in liquid form.

You should use the same brand of Irish Moss every time you brew. Different brands may contain different levels of active ingredients.

Whirlfloc VS Irish Moss – Which One Should You Use?


The choice between Whirlfloc and Irish Moss depends on how much haze you want to remove.

If you’re brewing a very hazy beer, then you probably don’t need to add either one. However, if your beer already has a lot of haze, then you might want to consider using both.

In this case, you’d start off with just a small amount of Irish Moss. Once the beer had cleared up, you could increase the amount of Irish Moss until the haze disappeared completely.

When adding Irish Moss, you’ll notice that the beer will foam up quite a bit. This is normal. Once the beer clears up, you can stop adding Irish Moss.

In comparison, when using Whirlfloc, you won’t get as much foam. This means that you’ll be able to tell when the beer has cleared up.

As long as the beer isn’t too foamy, you shouldn’t need to adjust the dose of Whirlfloc. Once again, the best way to find out what dose of Whirlfloc you need is to experiment.

Start with a low dose and see how the beer behaves. Then gradually increase the dose until the beer clears up.

Other Fining Agents

If you’ve used any other finings agents before, you might remember their effect on the beer.

For example, gelatin tends to cause the beer to have a thicker mouthfeel. Some finings agents can even change the color of the beer. For example, isinglass can turn clear beer into cloudy.

However, there’s no reason for you to worry about this. All finings agents do exactly the same thing: They remove protein from the beer.

So, regardless of whether you use them or not, the end result is always going to be the same.

Which Type Of Fining Agent Is Best?

All fining agents work equally well. The only difference is in cost.

Some fining agents are more expensive than others. If you plan to make multiple batches of beer at once, it might be worth buying a large quantity of cheaper fining agents.

This way, you’ll be able to save money over the course of several months.


Irish Moss and Whirlfloc are two common finings agents. Both are effective at removing protein from beer.

Although some people prefer the flavor of Irish Moss, Whirlfloc is better suited for those who like a lighter-tasting beer.

Andrew Carr
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