Although wine usually contains only grapes, yeast, and a small amount of sulfites, which are added and created during fermentation, the processing of wine introduces small amounts of substances which may be of concern to vegetarians and vegans.
Every wine is different and no uniform formula exists for producing wine.
The taste of a wine is a reflection of where its grapes were grown. The soil gives the wine its flavor, which is why wines produced in certain areas have a distinctive flavor. Winemakers may choose not to extensively process their wine in order to retain some of these natural qualities. A clarifying or fining agent makes wine clear by removing proteins from the wine. The agents eventually settle out of the wine.