What are Fining Agents?
If you are new to home brewing, you might not know what fining agents are or how they are used. You’re probably just focusing on the two most important things when making your own beer and wine; cleanliness or sanitation and patience. Once you master those two things, you’ll probably find that you need to refine some of your home brewing skills, specifically making a crystal clear beer. But where do I start? If you are doing some researching, you’ll probably see a lot around Irish moss, gelatin or Super-Kleer. Let’s clear it up.
Fining agents, or clarifiers, are derived from many different sources and have the same goal—to clear your beer or wine. During the brewing and fermentation process, you’ll probably notice that there are many suspended particles that are made up of proteins, yeast, or other particles from the must or trub in your fermenter or carboy. That’s great to have during some of this process, but there’s a certain expectation of having a clear wine or beer when you are ready to bottle. That’s where fining agents come into play. They help clear all of that up before you rack to your bottling bucket.
How They Work?
Fining agents can be added pre and post fermentation, and naturally serve the same purpose—to attract suspended particles, weigh them down and settle out of the liquid into the trub. Other fining agents can absorb unwanted aromas or flavors. An important note is that there is no one perfect element or material that will cure all haze or cloudiness in your homebrew. The idea is to understand the best agent to improve or develop your beer or wine.
Most Common Fining Agents
1. Bentonite: is a unique clay made from volcanic ash that is negatively charged and naturally absorbs suspended particles to use as a clarifier in the home brewing process. It’s mostly used at the beginning of fermentation of most wines, but is found to be quite effective in the secondary fermenter of most, if not all, beers.
Bentonite needs to be mixed in a cup of boiling water to create a slurry to then be added to the fermenter.
To use for wines, add the hot water to the fermenter and mix the appropriate amount of bentonite and stir quickly. The amount will vary depending on your batch size, but should be added before the wine must. During the fermentation, the bentonite will settle to the bottom quickly, however the fermentation will agitate the bentonite to mix through the solution, attach to positively charged particles, and swell to 20 times their size. Throughout the fermentation process, these large particles will sediment out of the solution and join the dead yeast and other unwanted solids at the bottom of the vessel.
Using bentonite on beer is a similar process. Boil some water to mix with the dry bentonite and add to the empty fermenter, then rack the beer. The mixture will evenly distribute and will eventually settle out making a clearer beer.
2. Gelatin: is a protein, which is found in various animals, that is made from collagen. It is positively charged, and widely used as a clarifier in beer. Gelatin is the same substance that would be found in Jello, and has a natural ability to coagulate multiple haze-causing particles in beer and wine.
This substance has been found to be most effective at cold temperatures making a bit more difficult to work with then bentonite. If you have a fridge or freezer that is dedicated to home brewing, this would be a great product to keep on the shelf as you cold crash and clear your beer.
3. Kieselsol: Typically used in conjunction with gelatin or chitosan, this is normally a liquid solution that is negatively charged and also known as silicon dioxide. You can find Kieselsol, or Silica, in most wine kits and is most effective when the fermented wine is completely degassed. It’s generally good practice to allow two full weeks before bottling for this substance to settle out all unwanted particles.
4. Chitosan: The second part of a dual fining process is this liquid element that is made from exoskeletons of crustaceans. Chitosan is positively charged and will attract the particles that its partner, Kieselsol, won’t attract and settle out of the beer or wine.