When it comes to brewing great beer, clarity is more than just looks—it’s a sign of quality and careful process control. One of the most effective tools for achieving bright, stable wort is kettle finings, particularly those made from carrageenan, a natural seaweed extract. But why are kettle finings so important, and how do they make such a difference in your brewhouse?

The Science Behind Kettle Finings

Kettle finings, available as easy-to-use tablets or granules, are added to the wort during the final stages of the boil. Their star ingredient, kappa-carrageenan, is a plant-based polysaccharide with a unique ability to bind haze-forming proteins. In hot wort, carrageenan molecules take on an open, flexible structure that helps them catch positively charged proteins and other particles responsible for haze. As the wort cools, these complexes clump together, forming larger aggregates that settle quickly in the whirlpool or during cold crashing.

The Real-World Benefits

What does this mean for your brewery?

• Cleaner wort, less haze: Kettle finings remove a significant amount of haze-forming proteins and fine particles, giving you a naturally bright wort and reducing the need for later fining additions.
• Better fermentation: With fewer unwanted particles, yeast can work more efficiently, boosting fermentation rates and attenuation.
• Enhanced filtration: By compacting sediment and reducing fine particles (especially those under 2 microns), kettle finings help cut down filter run times and avoid clogging.
• Increased beer stability: Removing proteins early on helps preserve colloidal stability, which is key for packaged beer shelf life.
• Process efficiency: Kettle finings are classified as processing aids, so they don’t require label declaration and help minimize losses by compacting trub and yeast sediment.

How and When to Use Kettle Finings

Timing is critical for getting the best results. Some products* are typically added about 10 minutes before the boil ends, while more refined options** can be added at the end of the boil or at whirlpool. The key is allowing enough heat for the carrageenan to unwind and interact with wort proteins.

Optimal dosing matters, too.*** Too little fining leaves haze-causing material behind; too much, and you risk forming fluffy rather than compact sediment. The pH of your wort also impacts effectiveness, with the ideal reaction happening around pH 5.3.

Take a look at our Kettle Finings Optimisation step-by-step guide

With kettle finings, you’re not just getting clearer beer—you’re building a more efficient, stable, and consistent brewing process. Don’t let haze cloud your quality; make kettle finings a key part of your brew day routine.

For more information or guidance on this process contact the Murphy’s Technical Team on sales.us@muphyandson.com

*Protafloc 
**Koppakleer 
***Our optimisation kit 

Written by Alan Windhausen, Murphy’s Technical Manager