Term (also flor yeast) for special yeasts of the species Saccharomyces bayanus, capensis, cheriensis, fermentati, montuliensis and rouxii. These are able to convert the sugar into alcohol in the first anaerobic phase (without oxygen) of fermentation. The flor yeasts can then switch the metabolism to aerobic (with oxygen), so that a waxy, initially white coating is formed from alcohol and oxygen, which coats the individual yeast cells. This causes the yeast cells to rise to the surface and form a centimetre-thick layer (film), which becomes increasingly brown in colour.
This protects the wine from air and prevents further oxidation. This...
As honorary chairman of the Domäne Wachau, it is the easiest and quickest way for me to access the wein.plus encyclopaedia when I have questions. The certainty of receiving well-founded and up-to-date information here makes it an indispensable guide.
Hans-Georg Schwarz
Ehrenobmann der Domäne Wachau (Wachau)