(WSJ) - WHAT ARE THE WORLD’S most unlikely wine-producing countries? India, Russia, China? It may surprise you to learn that China has one of the world’s largest wine industries, with more than half a million hectares now planted with vines.

I have touched down in some unusually located vineyards—Brazil springs to mind—so I wasn’t surprised to hear that Mexico has a fast-growing wine industry. What did surprise me, though, was just how old it is. By common consensus, it seems vines were first planted there in the 1530s by Spanish settlers. One estate can trace its lineage back to 1597. Even by European standards, where there are centuries-old châteaux, 450 years is a long time to be in the wine game.

I expect many of you reading this will never have come across Mexican wine. After all, this is a country known more for its gassy lager and tequila than its grapes. But that’s slowly changing, and wines from regions like the Valle de Guadalupe on the Baja California peninsula, a few hours’ drive south of San Diego, have found their way onto various restaurant wine lists and specialist shops. But not many. Few are exported to Europe and tracking those down is no easy task.

In the spirit of adventure—and if only to taste the oldest wine produced in the Americas—I decided to delve a little deeper.

Mexico’s wine industry is centered around the Valle de Guadalupe, although there are other areas that grow grapes—namely Zacatecas and the Valle de Parras, where internationally recognized varieties such as Cabernet Sauvignon, Tempranillo, Zinfandel and Chardonnay have been planted.