What are Clearing Agents used for in Wines?
Good quality wine should be clear. If you are new at fermenting wine, then you must have experienced moments wherein your wine came out cloudy. A cloudy wine means that there are small particles that have suspended within the liquid that have formed during the fermentation process. This is normal and wines eventually clear up through racking but if it doesn't, then you can use fining agents for your wine to aid in clarification.
To get all the suspended particles out, a fining agent is used so that it bonds with the charged solids thus forcing them to settle in the bottom. In the past, fining agents would include fish bladders, clay and bull's blood. It does sound nasty, but you don't really have to use them today as there are now chemicals available to help clear your wine. There are several types of fining agents that winemakers use when making wine today.
One of the most common fining agents is bentonite. Bentonite is negatively charged and is made from volcanic clay. It works by attracting positively charged particles from the wine. You know that it is working effectively when it swells into a huge ball and once it does, you have to take it out.
Chitosan, on the other hand, is a positively charged fining agent. It is made from the exoskeleton of crabs and shrimps and is often used with other negatively charged fining agent for effective removal of solids.
If you don't have access to these fining agents, then you can use egg whites and gelatin. Both are positively-charged. Egg whites are often used to clear red wines during the aging process. Gelatin, on the other hand, is also used in both red and white wine but too much of it can cause the wine to have a hazy appearance on the liquid.