What Is Whirlfloc?

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Beer brewing generally requires adding clarifying agents to the wort before boiling. Fine beer is often good because it is clear, and this clarity is usually achieved through the addition of Irish moss or Whirlfloc. Both products cause proteins and other particles to clump together. So, what is Whirlfloc?

What Is Whirlfloc?

Whirlfloc is a brand of flocculant used by brewers to improve the clarity of their beer. It’s a tablet of powdered Irish moss (Chondrus crispus) and purified carrageenan that is added to the boil. Whirlfloc helps to coagulate proteins and other haze-causing particles so that they can be removed from the wort before fermentation. This results in a brighter, clearer beer.

The best time to add Whirlfloc is 5-10 minutes before the end of the boil. This allows enough time for the Whirlfloc to work its magic without extracting too much bitterness from the hops. It also allows the Whirlfloc to be evenly distributed throughout the wort.

An image of a foamy beer

Too much Whirlfloc can make your beer taste astringent, so it’s important to follow the directions on the package. Generally, one tablet is adequate for 5-10 gallons of wort. You don’t want your beer to taste like a mouthful of salt, so be sure to add Whirlfloc sparingly at first and then adjust as needed. This way, you can find the perfect balance for your beer.

How Does Whirlfloc Work?

It works by forming a colloidal solution with the brewing liquor when added to the boil. This solution is then rapidly thrown into suspension by the vigorous boiling action. The result is a hot break that is more complete and quicker to settle out than without Whirlfloc.

It also contains carrageenan ingredients, which have a strong flocculating effect on yeast cells. Therefore, after fermentation is complete, the addition of Whirlfloc will cause the yeast to clump together and settle out more readily during racking and bottling operations.

For brewers concerned about carrageenan use, rest assured that it is completely safe and has been used in the food industry for many years. Carrageenan is derived from red seaweed (Rhodophyta) and is perfectly safe for human consumption.

When Should You Add It to the Brew?

Adding Whirlfloc requires proper timing so that you don’t hinder the boil or introduce off-flavors to your beer. The general rule of thumb is to add it in the last 10 minutes of the boil. This will give it enough time to work its magic without causing problems.

Most of the time, you can just add it to the boil without any other special considerations. However, if you are brewing a high gravity beer or using a lot of adjuncts, you might want to add it a little earlier. This will help to prevent boil-overs and ensure that the hot break is as complete as possible.

How to Use Whirlfloc

Whirlfloc is available in tablet or powder form and will come with specific instructions on how to use it. However, the following are general guidelines for adding it to your brew:

  • If using the tablet form, dissolve it in a small amount of water before adding it to a boil. This way, you can be sure that it will dissolve completely and not clump up.
  • If using the powder form, simply add it directly to the boil.
  • Add the Whirlfloc in the last 10 minutes of the boil to ensure that it doesn’t cause any problems.
  • You might want to add it a little earlier for high-gravity beers or those with a lot of adjuncts.
  • Be sure to stir it in well so that it dissolves completely.
An image of a glass of beer

What Are the Benefits of Using Whirlfloc?

There are several benefits to using Whirlfloc that every brewer will want to take advantage of to produce the best beer possible.

  • It helps to create a more complete and quicker hot break.
  • It flocculates yeast cells, which makes racking and bottling operations easier.
  • It is derived from natural ingredients and is perfectly safe for human consumption.
  • It doesn’t cause problems or impart any off-flavors to the beer when used properly.

Frequently Asked Questions

How Long Are Whirlfloc Tablets Good For?

Whirlfloc tablets have a shelf life of about two years if stored properly. However, it is always best to check the expiration date on the package before using them. Also, keep them in a cool, dry place out of direct sunlight.

What Does Whirlfloc Do to Beer?

Whirlfloc helps to clarify beer by causing the proteins and yeast cells to clump together and settle out. This results in a brighter, clearer beer that is less likely to cause off-flavors.

Do I Need to Use Whirlfloc?

No, you don’t need to use Whirlfloc to brew beer. However, it can help clarify the beer and make it less likely to cause off-flavors.


Beer clarification is an important part of the brewing process, and Whirlfloc is a great way to do it. This natural product is safe for human consumption and won’t cause any problems or off-flavors when used properly. It’s also easy to use and can be found at most homebrew shops.