Fining and Sediment
Racking normally takes care of most of the sediment found in wine, by transferring the clear wine from carboy to carboy. However, often some sort of fining, or clarifying process is desired before bottling to be sure that the wine is clear and free of sediment.
Fining is the process of making proteins in a wine clump together so it can easily be removed. Fining is different from filtering. Filtering uses filter paper to remove all items over a certain size from a wine. Fining in comparison gets all the tiny proteins to clump together so they specifically can be removed. The purpose is to make the wine more clear.
In olden times, winemakers used egg white, gelatine from hooves, blood, seaweed, and clay to do their protein clumping. These items would collect the impurities in the wine so that it settled at the bottom and was easily racked away. Modern winemakers tend to use components specifically designed to the purpose.
Common fining agents are sparkolloid or gelatin. Sparkolloid works well on white wines, usually 1 tsp per gallon. It might also take months for the sparkolloid to fully come out of the wine. Bentonite is also good on whites, although it works best if the wine is kept warm while it settles out. Both sparkolloid and bentonite pull out positively-charged particles.
Gelatin pulls out the negatively-charged particles, tannins and astringency from reds. The gelatin itself is positively charged, and as we know from high school, opposites attract. Isinglass works on the same principle.
There are certainly still wineries out there who use traditional ingredients such as clay and egg white.
If your aim is solely to get out larger-than-x-size clumps, you can use actual filters to run the wine through.
Glossary of Winemaking Terms
All content on the WineIntro website is personally written by author and wine enthusiast Lisa Shea. WineIntro explores the delicious variety and beautiful history which makes up our world of wine! Lisa loves supporting local wineries and encouraging people to drink whatever they like. We all have different taste buds, and that makes our world wonderful. Always drink responsibly.