Most wine is not vegan per se; the filtering agents used are most often derived from animal products. I was a vegetarian for 24 years and off-and-on vegan during that time, and since then go through periods of eating no meat or animal products. I raised my kid vegetarian even so ask me anything LOL 😂
Now your average vegetarian doesn’t care, because most still eat dairy and chicken eggs, but vegans eat no animal products at all and try not to use any animal products at all (leather, fur, etc). The whole point of veganism is to do no harm to animals, whereas as with vegetarianism it’s more a matter of eliminating meat as a matter of personal taste, health, or religion. Thus vegans wouldn’t drink wine unless they knew it was made without the death of animals involved
“The reason that all wines are not vegan or even vegetarian-friendly has to do with how the wine is clarified and a process called ‘fining’. … Traditionally the most commonly used fining agents were casein (a milk protein), albumin (egg whites), gelatin (animal protein) and isinglass (fish bladder protein).”
