In Reflections of a Wine Merchant (Reviews, Jan. 28), Rosenthal offers readers a fascinating glimpse into the wine trade.

What led you into the wine trade?

My daughter's birth was a turning point. I wasn't happy about practicing law and actually wanted to write, but couldn't make a living. My parents owned a pharmacy. They turned the luncheonette [part] into a liquor store and were trying to sell it. I took it over and turned it into a wine shop, so wine was something of a fluke. It's a work I love, but it's still work. There's a misperception that a wine merchant's life is filled with tasting wonderful wines and eating wonderful food, but it's labor, like owning a restaurant.

Your book is as much about relationships as wine and trade.

I became very involved in my business relationships, especially with grape growers. And their families and their children as well. I would never minimize the fact that you find a line of work to earn a living, but doing any kind of business requires that you cultivate relationships that are part of it. Honesty and integrity are essential components. The respect must be mutual, and not simply commercially. It's necessary to conduct business this way whether it's a multimillion-dollar corporation or a small-potatoes operation like ours.

How do you view the art of winemaking today?

We're in the modern age, but doing work people have done for thousands of years. I have this image of someone in my family some centuries ago taking his wooden cart and his produce and going from town to town to conduct trade. Not as an exercise in nostalgia or sentiment, though. Now we're at this potentially devastating crossroads. It's very difficult for these small families to maintain these appellations. The interest isn't there in the younger generations—the modern world calls to them. And the value of land is astronomical, so when an opportunity to sell comes, it's almost impossible to resist. On the other hand, these family traditions are deeply grounded, so it's hard for them to give up.

What impact did your own farming have on the book?

Once I became a farmer, I gained real appreciation for it, which in turn informed my work as a wine merchant. And it made an enormous difference in the writing of this book. I could not have properly expressed my ideas about the wine trade in the same way had I written it before I started farming. Everyone has contact with dogs and cats, and maybe some experience with horses. But a farm is a different operation altogether.