“I belong to the first class that studied ­winemaking in school, professionally,” he said. “My particular innovation was that instead of working in the Douro” — Portugal’s traditional wine region, farther north — “I decided to head south to the unsung Alentejo. It was my good luck to get in on the ground floor of the worldwide growth of wine and ride that wave.”

When asked the difference between Portuguese wine and that of other nations, Mr. Duarte didn’t hesitate. “The wines of Chile and Argentina are too sweet,” he said. “You think Spain, you think the tempranillo grape. Well, we don’t use the same grapes everyone else does. We have 315 different grape varieties, many of them unique to us. We’ve also taken many French grapes and adopted them for our own use.”

With a wave of the hand, he indicated the glasses on our table, still filled with the remnants of his elegant, delicious vintages, including several (of his own label) that have regularly landed in the Wine Enthusiast magazine’s Top 100, and said: “You want a velvety and well-balanced wine at a good price? Think Portugal.”

After lunch, elevated by the previous two hours of eating and drinking, we strolled a bit in the nearby vineyards. It was late afternoon, the sun low in the sky, and in the lengthening shadows, workers were still on the job industriously trimming the vines. The air was filled with nostalgic aromas of earth and mown grass, and as we walked, I found myself remembering my own near-exile in Italy, a place where I’d spent a total of eight years. Different from the Alentejo, Italy is long accustomed to being a sightseeing shrine of sorts, and its tourist treasures, as extraordinary as they are, often have a kind of annealed feeling to them, as of having been visited so often that they’ve been buffed smooth by the experience.

But Portugal, and particularly the Alentejo, give an entirely different impression: that of a place — showcase mountain towns apart — still waking up to its own worldly importance, and as a result, still vivid and sparklingly fresh.

We had, meanwhile, been walking in a large circle and were almost returned to the main building when we saw a dog, a golden retriever, amble out to greet us. The animal was immediately approached by a barnyard cat. Instead of fighting, the two touched noses. “Around here,” Martin said with a wry smile, “everyone’s so happy that even interspecies enemies kiss and make up.” We laughed and turned back toward the car. It had been five days in that peculiar suspension of real life known as the road trip, and it was time to go home.

Several hours later, back in the airport in Lisbon, I hugged my old friend goodbye. I was relieved to have found him at peace in his adopted country. There’s an essential melancholy in exile, a sadness from the severed connections to family, habit and what the poet Paul Celan called the “fatal once-only” of the mother tongue that can weigh on those who’ve made the move.

In Martin’s case, these deficits were offset by a good marriage, his unswerving devotion to his art and a country whose ancient ways allowed him the kind of concentration that speeding New York would have almost certainly denied him. In the process, coincidentally, that country had offered me two things: a reassuring insight into the adaptability of human nature over time, and a tour of the hilly, magical Alentejo, and with it, some of the very best eating and drinking of my life.