Dear Dr. Vinny,
Generally speaking, do wine grapes like Cabernet Sauvignon or Chardonnay (for example) taste any different when eaten than the basic green/purple/red grape varieties one can buy at the average grocery store? Also, are they normally available from any common sources if one was curious about tasting them in their "natural" form?
—Thomas R., Lancaster, Calif.
Dear Thomas,
One taste of a wine grape and you'll see instantly that wine grapes and table grapes are selected based on some very different characteristics. When ripe, most wine grapes will be much sweeter, softer and juicier than table grapes. They'll also have thicker, chewier skins and more prominent seeds. Table grapes are often bigger, more crispy and crunchy, with much thinner skins and smaller seeds or none at all. Table grapes are also selected to withstand different types of travel and handling, while wine grapes are often picked much riper than table grapes and so will deteriorate faster when picked.
Interestingly, it can be difficult to tell the difference between the varieties of wine grapes in their grape form by taste alone. Sure, you get visual cues from leaf and cluster shape, but even some winemakers might not be able to tell the difference between a Zinfandel grape and a Merlot grape just by eating them.
Wine grapes typically aren't commercially available for snacking, with the exception of Muscat grapes, which I sometimes see in grocery stores. But if you head to a winery around harvest time, ask to taste a sample.
—Dr. Vinny
http://www.winespectator.com/drvinny/show/id/5045
