But aren't all wines vegan?

NZ Vegan Society label

Well, you would think so right - being fermented grape juice. But, in the pursuit of clean, clear wines, fining and filtration are commonplace. Fining is defined as the addition of a substance that encourages solid particles in wine to clump together. The conglomerated particles then sink and can be removed by settlement or filtered off. Some traditional fining agents are egg whites, milk protein (casein), fish protein (isinglass) and gelatine, all of which would make a wine vegan unfriendly. Vegan friendly fining agents include clay (bentonite) and vegetable protein.

With the rise in the number of people choosing to reduce their intake of animal products it is becoming increasingly common for fining agents to be noted on wine labels - but this isn't always the case. In fact, labelling laws only require that allergins are noted on wine labels, meaning that some fining agents do not need to be noted at all. 

But all is not lost for vegan wine drinkers! In New Zealand many winemakers are choosing to show the New Zealand Vegan Society label on wines made without the use of animal products.