That glass of wine you enjoyed with dinner or paired with your favorite cheese (or cookies!) has grapes and yeast, sure, but there’s also a good chance there are additives in there, such as sulfites, oak barrel, or even egg whites. That’s right; your wine might not even be vegan! Read on to get the full breakdown of natural wines so you can know how to look for a bottle the next time you shop.

What Is Natural Wine?

Defining natural wine is tricky because there’s no official definition and no organization for consistent regulation. Without getting into the nitty-gritty details of the long and difficult winemaking process, natural wine is made from pure, fermented grape juice. That means there are no additives such as sulfites (more on that below), chemical fertilizers, or pesticides, and it’s made with as little modification as possible. If you’re wondering how the organic wine label comes into play, that’s a whole different ballgame. Organic wine is made from grapes grown without any chemicals, but additives or chemicals may still be added during other steps of the winemaking process. So, natural wines are organic (since they’re made without chemicals), but not all wines labeled organic can be considered natural.

The Difference Between Natural Wine and Traditional Wine

The process of making natural wine isn’t the only difference when comparing them to other wines. Expect to find a pretty significant difference in look and taste. For starters, the color of natural wine can appear cloudier than the red or white wines you’re used to buying because the wine is unfiltered. The flavor profile might have little flavor difference compared to your favorite traditional wine, but some natural wines have a sharper, funkier flavor.

Sulfites in Wine

Sulfites are a chemical preservative added to wine to protect against spoilage and keep wine stable during shipping and storage. According to James Kornacki, Ph.D. and founder of Üllo Wine Purifier, “sulfites protect the natural flavor profile of a wine and may even temper ‘off-flavors’ that may be present.” With all the natural wine explanation covered, Kornacki says some sulfite compounds are “produced naturally during fermentation but in quantities insufficient to protect against oxidation and microbial growth.” So some natural wines have sulfites in trace amounts (around ten parts per million (ppm) versus the higher amounts of sulfites some winemakers add. Quantities can reach up to 350 ppm, the max for the U.S. The semi-alarming thing about sulfites is they’re actually banned as preservatives in fresh foods (meat and produce). But Kornacki says since no other preservatives are “uniquely capable of preventing oxidation and microbial spoilage, sulfites have found continued use in winemaking to produce the types and variety of wines the world has come to expect.”

Sulfite Wine Filters

Many people experience adverse or allergic reactions to high levels of sulfites, but it’s debated whether it’s a cause for those red wine headaches. If you can’t find a natural wine you like or would prefer to stick to the under-$10 section at your store, a wine filter is a great way to enjoy a glass without the adverse effects of sulfites. According to Kornacki, the Üllo Wine Purifier’s process selectively removes sulfites once their job as a preservative is finished (when you open the bottle). “This selective removal helps the naturally nuanced and complex flavor profile of any wine revealed itself as the level of sulfites is brought closer to naturally occurring levels, like how it was at the vineyard,” he says.

Where to Buy Natural Wines

Big cities like New York, Los Angeles, and Chicago take the natural wine movement pretty seriously, with shops and bars dedicated to selling only natural wines. If you don’t live in an area with a boutique shop for natural wine, there’s a good chance your local wine shop will have some in stock. Restaurants may even offer you two different wine lists, one for regular wines and one for natural wines. (Here are 11 new natural wine options recommended by our sister site, Food & Wine.) And since the labeling process isn’t necessarily going to tell you whether it’s natural or not, it’s a good idea to ask the staff what they’ve got. You can also check out some online wine shops.