fining, winemaking process with the aim of clarification and stabilization of a wine whereby a fining agent, one of a range of special materials, is added to coagulate or adsorb and precipitate quickly the colloids suspended in it. Fining (collage, or ‘sticking’, in French) is important because, by encouraging these microscopic particles to fall out of the wine, the wine is less likely to become hazy or cloudy after bottling.
Most young wines, if left long enough under good conditions, would eventually reach the same state of clarity as fining can achieve within months, but fining saves money for the producer and therefore eventually the consumer. Fining is most effective in removing molecules of colloidal size, which include polymerized tannins, pigmented tannins, other phenolics, and heat-unstable proteins. (Other reasons for clouds, hazes, and deposits in bottled wines include tartrates and bacteria. See stabilization for details of other methods of removing them.)
