(WineMag) - A beverage made from pressed grapes must be vegetarian, right? Well, some winemaking techniques can make certain bottles a no-go for the animal-friendly crowd. Learn how animal derivatives end up in your wine, and how to spot vegetarian- and vegan-friendly wine.

Wine is made from grapes, but that does not necessarily make it vegetarian or vegan. Some winemaking methods make surprising use of animal-derived products, which is why an increasing number of producers state whether the wine is vegan or vegetarian on the label. But what does it mean?

Some winemaking basics first: Traditionally, winemaking is a slow process. Pressed grape juice needs to settle during fermentation to let the suspended solids sink to the bottom of the tank or barrel.