Eight Hundred Grapes by Laura Dave

When Georgia Ford discovers that her fiancee has a young daughter that she didn't know about, she escapes to her family's vineyard in Sonoma to think about if she still wants to get married.  There, she learns that her family is falling apart. Her father, Dan, whom she adores, has sold the small winery he started to a big corporation that cares more about making money than producing wines with care. Jen, her mother, has reunited with an old love, Henry, even though she's married to Dan. Meanwhile, Georgia's twin brothers, Bobby and Finn, are both in love with Bobby's wife, Margaret. Georgia is determined that the sale of the winery won't go through, but the buyer, Jacob McCarthy, won't back down. Jacob, while an adversary, is surprisingly in tune with Georgia's feelings and the upheaval in her family. Against the backdrop of California's wine country, Dave has written a novel about family ties and the meaning of home.