There is a note from the author at the end of this book, where he talks about how he really wanted to write about wine-making, but in an interesting way. He came up with the story, in which the main character owns and operates a winery, so he could describe the process of making wine. It shows.
The characters are usually the part of a story that draws me in, but these characters weren't great. The dialog is stilted and flat, the characters make weird, inexplicable decsions, and (it makes me sad to say this) the stuff about how wine is made is still pretty boring - and,worse, it doesn't fit. The story is not moved forward by the descriptions of the fields, the equipment or the process. Those sections feel like they were written separately then inserted into the story.
The main character talks much more about his relationship with his dogs than with his daughter. The fact that he gets all the way from CA to London before he realizes that his daughter will be upset to learn about the death of her mother makes him pretty unlikeable. Then, when he does tell his daughter, her reaction is completely strange. The family relationships just don't ring true.
I won't be reading any more in the series, although I will say that with some work on dialog and characterization, these could be good books.