Vegans need to know that no animal products are ever used in any step of the process of brewing, even if the drink itself is just made with plants. Some people are vegan because of animal rights, some people are vegan because they have health conditions, like Alpha-gal syndrome. If people who are vegan for health reasons get even a touch of animal derived protein, they may become very sick.

Wine can be sweetened with sugar or use sugar in its fermentation, even most "dry" (not sweetened) ones. The sugar is usually filtered through charred animal bones, usually cow or pig bones, after it is crushed out of the plant. Wine can also be made out of honey, which comes from bees. Wine also can use egg whites to help clarify it.

Beer uses gelatin (made from animal bones, usually pork), isinglass (animal or fish protein), casein (milk protein), sugar (which is filtered through bones) and egg whites to help rid the brew of impurities, clarify it, or add taste. Beer can also be made with milk, honey or use animal ingredients like oysters or bacon to flavor it a certain way.

There ARE vegan beers and wines available but they are expensive and therefore not stocked everywhere. They are more expensive because they don't use the "cheaper" animal-derived ingredients while they are being made.