South Africa's wine industry continues to expand, the number of wineries has nearly doubled and the country's exports to the United States have risen steadily. Though small wineries are the driving force behind a large portion of this growth, many of their wines are still difficult to track down in wineshops and restaurants Stateside. Yet bottlings from these smaller producers offer quality and bring diversity to the marketplace. Here's a selection of promising South African wineries that have recently entered the U.S. market. Wine Spectator's senior editor James Molesworth explains.