Vegan wines

Wine is cloudy after fermentation. In the recently trending natural wine boom, wines are often left unfiltered. But the vast majority of the world's wine drinkers want to drink their wine clear, without the tiny particles left behind by grape skins and yeast residues. Filtration is also important because if active yeast particles remain in the wine, even the small amount of residual sugar in a dry wine can provide enough nourishment for the yeast, triggering unwanted secondary fermentation in the bottle.

Traditional processes for filtering wine have included animal-derived ingredients. The added agent collects the tiny particles around it like a magnet, allowing them to be removed from the wine along with the fining agent. Well-suited for this task have been milk protein casein, egg white albumin, animal protein gelatin, and so-called isinglass (a fining agent made from fish swim bladders). The agent used for filtration is of course removed in the process, but tiny traces of it may remain in the final wine. For this reason, wine clarified using traditional methods might suit a flexible vegetarian's diet if, for example, casein or albumin has been used. But for vegans, these wines simply won't do, as you can never be sure whether residues remain in the final product.