Wine Clarification, Filtration & Fining Agents

First, some definitions;

Clarification

The process, natural or induced, whereby ‘unwanted’ suspended particles are removed from a wine and it subsequently becomes ‘clear’.The best example of natural clarification is the sedimentation of yeast cells at the end of the alcoholic fermentation. Further clarification can be ‘induced’, for example by fining and/or filtration or centrifugation of the wine.

Stabilisation

A set of procedures used to ensure that the wine stays clear and does not spoil. Initially, stability tests are undertaken for substances that might come out of solution and damage the appearance of the wine, such as proteins and tartrates. If any of the tests suggests ‘instability’, then the winemaker intervenes by, for example, removing the protein by bentonite fining or chilling the wine to initiate tartrate crystallisation.

Fining

The addition of a substance or mixture of substances to the wine, in order to clarify, stabilise or modify its organoleptic qualities, which is subsequently removed.
Examples of fining agents are bentonite, which is used to remove proteins and gelatin, which is used for clarification.

Filtration

Passing wine or must through a media in order to ‘strain out’ the particles suspended in it. This is a purely physical process and involves the separation of liquid (wine) from any sediment deposits or ‘suspended’ particles. The size of the particles to be removed determines which of the many filtration systems and grades is required.