Term (also fine) for various processes to "embellish", "improve", "purify" or "preserve" a young wine. Degumming or clarification, on the other hand, usually refers to the processes for grape must. In the past, fining primarily meant the clarification of lees in a wine after fermentation (also known as flight fining). Today, the term encompasses many technical cellar measures. Some overlap with preservation methods, which are primarily intended to increase shelf life and prevent spoilage.
During fining, the addition of suitable substances to the freshly fermented wine binds suspended matter through chemical reaction and/or adsorption, which can have a negative effect on colour and taste. These are either negatively charged, such as yeasts and tannins, or positively charged, such as proteins and gelatine. The agents must be oppositely charged in order to bind the lees particles. They are added in dissolved form and form insoluble flakes with the unwanted wine ingredients, which sink to the bottom.
History
The Romans were already aware of the effect of whipped egg whites in ancient times. In the Middle Ages, there were some questionable methods (or wine adulterations); for example, a "colour and taste improvement" with bovine blood. In the famous classic "Von Baw, Pfleg und Brauch des Weins" by the clergyman Johann Rasch (1540-1612), who worked in Vienna, some techniques are described in detail. He explains how to restore a cloudy wine by adding freshly milked, still cow-warm milk. It was already known that certain substances such as isinglass, gelatine, Spanish earth (kaolin) and coal bind the suspended particles in the wine.
Mode of action
Several effects are achieved through fining. Above all, the natural settling of lees is significantly accelerated. Substances bound in the wine that can lead to turbidity after bottling are removed. In addition, the removal of filtration-inhibiting substances facilitates subsequent filtration. Finally, wine defects are prevented at best or eliminated if they occur. A distinction can be made between the three groups of physico-chemical substances such as proteins, tannins, crystals (tartar) and heavy metals, biological substances such as yeasts and bacteria and other substances such as dust, filter material and cork abrasion. Fining works best with wines...
