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 mainly referred to the clarification of lees in a wine after fermentation, also known as fining on the fly. Today, the term encompasses many different technical cellar measures. Some overlap with preservation methods, which are primarily intended to increase shelf life and prevent spoilage.
Fining involves the addition of suitable substances to the freshly fermented wine to bind unwanted suspended matter through chemical reactions and/or adsorption, which can have negative effects on colour and taste. These are electrically charged. Either negatively charged like yeasts and tannins or positively charged like proteins and gelatine. The fining 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 beaten egg whites in winemaking in ancient times. In the Middle Ages, there were some questionable methods (or wine adulterations); for example, "colour and flavour 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. Among other things, he explains how to restore a cloudy wine, namely by adding freshly milked, still cow-warm milk. It was also known that certain substances such as isinglass, gelatine, Spanish earth (kaolin earth) and coal bind the suspended particles in the wine.
Mode of action
The fining process ultimately achieves several effects. Above all, the natural settling of lees is significantly accelerated. It also removes substances bound in the wine that can lead to turbidity or negative impairment after bottling. In addition, the removal of filtration-inhibiting substances facilitates any 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...
