Heat-sensitive proteins; see under Schönen.
Collective (also fine) ponds for processes to "beautify", "improve", "clean" or "preserve" a young wine. Degumming or clarification, on the other hand, are generally understood to be the processes for grape must. In the past, fining mainly meant the clarification of the turbid matter of a wine after fermentation, which was also called flight fining. Today the term covers many different cellar-technical measures. By adding substances to freshly fermented wine, undesirable suspended solids are bound by chemical reactions and/or adsorption. All these substances are electrically charged. Either negative like yeasts and tannins or positive like proteins and gelatine. The fining agents must be oppositely charged in order to bind the cloudy particles to themselves. They are added in dissolved form and, together with the undesirable wine ingredients, form insoluble flakes that sink to the bottom.
The Romans already knew about the effect of whipped protein during vinification in ancient times. In the Middle Ages, there were sometimes questionable processes (or wine adulterations); for example, "colour and taste improvement" with cattle blood. In the famous classic "Von Baw, Pfleg und Brauch des Weins" by the in Vienna some of the techniques are described in detail by the clergyman Johann Rasch (1540-1612). Among other things, he explains how to restore a cloudy wine, namely by adding freshly milked milk still warm from the cow. It was also known that certain substances such as house bubble, gelatine, Spanish earth (kaolin clay) and coal bind the suspended particles in the wine.
Several effects are ultimately achieved by fining. Above all, the natural settling of turbidity substances is considerably accelerated. Furthermore, substances bound in the wine are removed, which can lead to cloudiness or negative effects after bottling. In addition, the removal of filtration inhibiting substances facilitates a possible subsequent filtration. Finally, wine defects are at best prevented at all or eliminated after their occurrence. A distinction can be made between the three groups of physico-chemical substances such as proteins, tannins, crystals(tartrates) and heavy metals, biological substances such as yeasts and bacteria and other substances such as dust, filter material and cork dust. Beautification works best for wines with a high acidity.
Optimal for many fining agents...