Here's a fun fact you may not know: not all wine is vegan. Some wine is clarified with "fining agents" that are made from animal products.
These fining agents help eliminate proteins, yeasts and other molecules that give wine a cloudy appearance. They can also eliminate harsh tannins, helping the wine taste smoother at a younger age, wine blog VinePair says. As The Kitchn explains, the fining agents attract molecules. By collecting around the fining agent, the molecules form larger particles that are then easier to filter out of the wine.
According to PETA, popular fining agents include, "blood and bone marrow, casein (milk protein), chitin (fiber from crustacean shells), egg albumen (derived from egg whites), fish oil, gelatin (protein from boiling animal parts), and isinglass (gelatin from fish bladder membranes)." Not only are these animal-based products used to filter the wine, they might also get absorbed into the wine in small quantities. There's nothing vegan about that.
The good news for all you vegans out there is that alternative, non-animal-based fining agents exist. Animal-free options include carbon- and clay-based fining agents. As the natural wine industry picks up steam along with the natural food movement, unfiltered or unfined wine is becoming more popular. Without fining agents, wine will typically become less cloudy on its own; it simply takes a little more time. Fining simply speeds up the process that may otherwise take a few months.
It's easy to distinguish unfiltered or unfined wine because labels usually advertise those characteristics as selling points. But you won't necessarily see wines labeled as unfriendly to vegans. As of now, there are no laws mandating that a wine label advertise what kind of fining agents were used in the bottle.
So how's a vegan to know? Check out PETA and Barnivore for good lists of vegan wines, and ask your local wine store about vegan options. Next up, consider the beer in your fridge, because that might not be vegan either.