Fining Agents Cheat Sheet

Properly clarifying your wine provides much more benefit than simply improving its visual appearance. Fining techniques and agents improve the color, odor, flavor, stability and mouthfeel of the finished product – along with many additional, subtle, benefits.

Most fining agents work by attracting the positively or negatively charged particulate matter suspended within the wine, causing these particles to bind to the fining agent and precipitate to the bottom of the fermenting vessel for effective racking. Below is a handy guide for making sense of the many fining agent options.

1.      Bentonite

  • negative charge 
  • continuously effective 
  • can be added at any stage
  • creates compact lees 
  • be sure to mix thoroughly

Negatively-charged bentonite will attract and bind to positively-charged particulate matter such as dead yeast cells (lees). It is unique in that bentonite can be added before or after fermentation, and is especially effective when added prior to primary. The action of CO2 gasses produced by the yeast will continue to stir the bentonite during fermentation, and a buildup of lees will form in the bottom of your fermenter indicating the bentonite’s activity. Be sure to mix bentonite with warm water thoroughly – if it is poured directly into wine it will clump up and lose efficiency.

2.      Chitosan

  • positive charge 
  • very effective clarifying action 
  • minimal impact on flavor and character 
  • can be used in low-tannin environments
  • use with Kieselsol
  • be mindful of shellfish allergies

Chitosan is a positively-charged fining agent made of chitin, typically from the shells of crustaceans and other shelled microscopic sealife. It will attract proteins, yeast, polyphenols and other negatively-charged particles, and is especially effective when used with its partner Kieselsol (which has a negative charge). One excellent property of Chitosan is that it does not require tannins to work properly, allowing its use in white wines, ciders, meads, and more. Many experts say that Chitosan will not trigger shellfish allergies, especially if proper settling and racking takes place, but we advise caution.  

3.      Kieselsol

  • negative charge
  • very effective
  • removes bitterness 
  • used after gelatin or Chitosan

Made of Silica Gel or Silicon Dioxide, this negatively-charged fining agent is most often used 1-3 days after fining with Chitosan or gelatin. Kieselsol creates a very compact lees and is notable for its reduction of peptide-tannin haze.

4.      Isinglass

  • positive charge
  • minimal impact on character 
  • improves mouthfeel
  • reduces astringency
  • reduces browning/oxidation of whites 
  • removes colloidal hazes
  • final polishing agent

Isinglass, derived from the swim bladders of fish, is an effective positively-charged fining agent most often used as the very last step in clarifying wine before bottling. Isinglass has a positive impact on the mouthfeel of wine, and is especially adept at removing harshness and astringency due to its activity of removing polyphenolic compounds. We recommend using other fining agents initially, then racking, and using Isinglass as the “Ising” on the cake for a perfectly clear, polished final product.

5.      Polyclar (PVPP)

  • minimally charged 
  • absorbs phenolic/polyphenolic compounds and catechins 
  • removes bitterness 
  • insoluable, no impact on flavor
  • deters browning and oxidation

Polyclar, the brand name for PVPP plastic particulate, is a unique fining agent that absorbs phenolic compounds and unwanted tannins as well and deactivates oxidative enzymes within the wine. It is especially useful for removing oxidative odors and preventing browning in whites and reds, especially when used in conjunction with activated charcoal. Because it is made of plastic, PVPP is insoluble in the wine and can be completely removed after settling into the lees. 

6.      Gelatin

  • positive charge 
  • reduces unwanted tannins and proteins 
  • removes bitterness 
  • improves mouthfeel 
  • used with Kieselsol 
  • red wines only

Derived from hooved animals, Gelatin is most often used for reducing astringency and binding excess, harsh tannins common to red wines. It is often used prior to, and in conjunction with, Kieselsol as they have complimentary chemical action. First administer gelatin to attract the negative particulate and excess tannins, then 1-3 days later a dose of Kieselsol will clean up the positive charges as well as neutralize any excess gelatin. We do not recommend using gelatin with white wines, which have a very low concentration of tannins – this is because excess gelatin can create protein instability, and actually cause cloudiness in the white. Be sure to purchase fresh gelatin, as it is an animal byproduct that will deteriorate over time.

7.      Sparkalloid

  • positive charge 
  • improves color through superior clarity 
  • minimal impact on character and flavor 
  • very effective clarifying action 
  • needs time to settle 
  • use with bentonite

Made from diatomaceous earth (the microscopic fossil remains of shelled algae), Sparkalloid is very effective at removing thick hazes caused by negatively charged tannins, or other fining agents. Sparkalloid must be allowed to settle completely and should not be used right before bottling, as racking of the clarified product is necessary. The combination of Sparkalloid with Bentonite is very popular, as it creates a compact lees for efficient racking. We recommend using a “hot” mix, meaning the agent should be thoroughly stirred in warm water before its addition.

Notable Mentions:

1.      Super Kleer

Simply a name-brand for a combination offering of Chitosan and Kieselsol, Super Kleer comes in a handy 2-packet kit and is extremely effective. Finish with Isinglass for a superior fining regimen.

2.      Irish Moss

Made from dried seaweed, Irish Moss is excellent at precipitating proteinaceous particles in beer wort. Do not use to clarify wine.

3.      Glycerin

Not so much a fining agent as a finishing agent, the addition of Glycerin at the end of your winemaking process will result in a smooth, refined mouthfeel with additional sweetness and body that compliments some wines greatly.

4.      Egg whites

Typically mixed with a dash of salt and water and whipped smooth, positively charged egg whites offer a silky smooth body to wine while absorbing harsh tannins. This results in less bitterness and it clears tannin hazes. Must be allowed to settle, followed by racking.

5.      Carbon (activated charcoal)

Activated charcoal is used in many industries for its color and odor neutralizing properties. Used in conjuction with PVPP, carbon can diminish off-putting odors and flavors caused by oxidized or browning white wines. Be very careful, as charcoal can strip your wine of color and flavor.

6.      Super Smoother

A finishing/smoothing formula rather than a traditional fining agent, Super Smoother combines Glycerin with Liquid Oak Extract for an easy and effective way to improve mouthfeel, body, and add an aged oaky character to your wine.