If you’ve ever wondered why you can’t head to the grocery store, pick up some concord, red, or green grapes, bring them home, crush them and turn them into delicious wine, congratulations, you’ve wondered what most people wonder but have been too afraid to ask: what’s the actual difference between table grapes and wine grapes? The answer? A lot, actually.

The first difference between these grapes is the species from which wine and table grapes originate. All grapes that are used to make that incredible glass of wine you’re currently swirling come from the Vitis Vinifera species, a species native to the Mediterranean, including Europe and the Middle East. But while some table grapes also come from this species, others come from species such as Vitis Labrusca, and Vitis Rotundifolia, species that don’t make great wine but are delicious to eat.

A second difference between these two grapes has to do with their skin thickness. Table grapes have thin skin, perfect for chomping into as you munch away, but that’s not ideal for making wine. When it comes to making great wine, especially red wine, a thicker skin is better, and that’s exactly what wine grapes have, perfect for imparting tannins and delivering that deep red color you enjoy staring at.

Sweetness is another characteristic where these two grape categories differ drastically. While you might think the opposite, wine grapes are much sweeter than table grapes, and that’s a necessary thing because grapes need a lot of sugar if yeast is going to convert their juices into alcohol. Higher sweetness comes from the species itself, along with the fact that wine grapes are harvested much later in the season than grapes meant for the table, allowing their sugars to concentrate as much as possible. Wine grapes are harvested at around 22-30 percent sugar while table grapes might be closer to 10 or 15 percent sugar. This also means wine grapes deteriorate much faster when picked than grapes meant for the table.

Size also comes in to play when comparing these two grapes, and in making wine, bigger is definitely not better. Wine grapes are often small, with concentrated flavors, exactly what you want for vinifying, while table grapes are large, bursting with juice and often a lot more water. Refreshing, sure, but that water means there is less sugar and, as we discussed above, that means the grapes won’t ferment all that well.

Finally, the yield of wine grapes compared to table grapes is incredibly different. While a winemaker is lucky to get ten pounds per vine of fruit — and often they want less if they’re making a premium vino — table grape producers use a trellis system that allows the grape bunches to hang without touching each other, providing the ability to produce thirty pounds of fruit. That much production would make a pretty terrible wine, but it creates delicious fruit for an afternoon snack. Just don’t try crushing and vinifying them.