Yet Sorte O Soro has a shivery, lingering elegance, like the cold that settles over O Bolo when the sun sets. Overnight, in a nearby village, the temperature fell to minus 7 degrees Celsius (about 20 degrees Fahrenheit).

“This is not Spanish wine,” Mr. Palacios said. “It’s much more like wine from Northern Europe, Germany maybe.” To thrive in the hardscrabble vineyards of eastern Galicia, you need either the confidence that comes from being part of a great winemaking family or deep roots and a passion for the terroir.

In the Monterrei region, southwest of Valdeorras along the border with Portugal, a home-grown vigneron, José Luis Mateo García, is making some of the best red wines in Galicia, under the label of his small winery, Quinta da Muradella. Monterrei is a forlorn place, where population flight has turned some villages into ghost towns. Only a few hundred hectares of vineyards remain, scattered seemingly randomly in tiny plots amid forests of lichen-covered trees. Mr. Mateo García’s vineyards grow a diverse range of grapes, including mencia, an elegant, floral red variety indigenous to the vineyards of Galicia and neighboring areas like Bierzo.

He seems to know every single vine, pointing out how this one was grafted onto older rootstock, how that one yields the most concentrated juice, and so forth. “I used to see this valley as one piece,” Mr. Mateo García said. “The more I work, I see it as a puzzle. Once I understand the different pieces I can complete the puzzle.”

Eastern Galicia is a poor place, but the poverty of its soils is beneficial. While a previous generation of growers tried to raise their yields artificially to compensate for nature’s limitations, conscientious producers like Mr. Palacios and Mr. Mateo García are going in the other direction. Lower yields generally mean wines with more character.

Yet there is more to the wines of Galicia than stark terroirs and harsh climates. In the west, along the coast near Santiago de Compostela, where the slopes are as green as the bogs of Ireland, a very different style of wine is produced. This, a region called Rías Baixas, is the home of the albariño grape, a fruity variety that thrives in friendlier climates.

Rías Baixas was the first region in Galicia whose wines attracted wider attention, filling a void in the Spanish market for a floral, aromatic white that works well with seafood, for example. Some growers insist that albariño is actually identical to riesling, the great white grape of Germany and Alsace.

Others are equally adamant that this is not the case, and no one seems to have offered conclusive evidence one way or the other. If it is indeed riesling, it is much more like the fruity, exuberant Alsacian kind than the steely, reserved German sort.

While some Rías Baixas is a bit too easygoing for my taste, at least one producer, Pazo de Señorans in Meis, near the city of Pontevedra, makes a very serious wine from albariño. The estate occupies a manor house north of the city of Pontevedra — considerably more comfortable surroundings than those occupied by most vignerons in eastern Galicia.

The vines are much more cosseted, too; instead of being forced to eke out an existence on bare sand or slate, they are lifted above lush meadows on pergolas, to protect the grapes from humidity.

When the owners, Marisol Bueno and her husband, Javier Mareque, arrived in 1979, much of the estate was covered with kiwi trees. They recognized the potential for wine production and progressively replaced the kiwi trees with vines. While the taste of kiwi and other, more exotic fruits pervades some albariño, Pazo de Señorans looks for more restrained flavors, said Ana Quintela, the winemaker. She aims to keep the wines fresh by avoiding malolactic fermentation — a second fermentation that, in many white wines, is used to convert malic acid to softer lactic acid.

The result is that the wines of Pazo de Señorans seem to blend the attractive fruit of albariño with a bit of the rigor, the structure, of the wines of eastern Galicia. Pilgrims should be entitled to an occasional indulgence once they reach their destination.