Many people have asked me why a wine is not vegan. Well… it might not be depending on the winemaking practices.
If wine is fermented, aged, and bottled without intervention then it is vegan. Grapes, yeast, barrels, and sulfites are all vegan.
If on the other-hand, the winemaker takes steps to speed up the release of the wine, or to correct an issue with the wine, then there is a possibility that something they used was derived from animals.
The thing that prevents a wine from being vegan has to do with fining. Fining is the process of adding something in order to bind with and remove something else.
There are a number of animal derived fining agents that are used in winemaking:
Gelatin – is derived from animal tissue – usually pork based. It binds with and removes tannins and makes a wine less astringent, and can speed up clarification. This reduces the amount of time a wine needs to age before it is bottled and sold.
Isinglass – is essentially gelatin derived from fish. It is very good at removing hazy particles so it speeds up the clarification of wine – generally used in white wines.
Albumin – is derived from eggs. Albumin is good at helping clarify red wines. It removes tannins a little more gently than gelatin does.
Casein – is derived from milk. It removes polyphenols. It is typically used in white wines to treat, or prevent pinking. Pinking is when a white wine develops a pinkish, or orangish hue due to oxygen exposure.
These fining agents are not required in winemaking, but they help get the wine to the consumer more quickly. Wineries are starting to look for non-animal derived products, but the list of fining agents that they are legally allowed to use in winemaking does not offer many good non-animal derived options yet. The industry is working on it, but the approval process is tedious and slow.