Round Pond's Sangiovese, Nebbiolo and Petit Verdot blend is smooth and refreshingly tart; its Merlot-Cabernet mix is subtler and more rounded. The twist? Neither is a wine. "People would tell us vinegar is so acidic that no one can tell the difference between grape varietals," says Ryan MacDonnell, 33, who proved the assumption wrong with two red wine vinegars that were launched last fall. Ryan and her 31-year-old brother, Miles, grew up surrounded by grapes: Round Pond, their family's Napa vineyard, has sold fruit to wineries such as Caymus for years. They decided to try producing vinegar commercially after tasting their parents' homemade versions—and after considering how few high-quality red wine vinegars were on the market. Round Pond uses a centuries-old French artisanal technique, which involves aging the vinegars in oak barrels for about 10 months. The finished products are complex and aromatic, with the distinct flavor of the wines from which they were made ($18 for 200 ml; 877-963-9364).