Verdejo is the most exciting grape varietal you’ve not-quite never heard of, more likely maybe have come across, maybe drunk a wine from, but probably never paused to consider its true capacity.. Verdejo sings in high registers and in low, pens irresistible pop songs and intricate ballads, fleetly enlivens a single night out and gradually annexes your recurring dreams.

Best for Verdejo are the soils in Spain’s Rueda, a DO (viticultural Denominación de Origen) in the country’s northwest community of Castile y León. The Duero river runs through Rueda, and farther west separates Spain from Portugal, where dry wines from the namesake Verdelho are interesting and getting better (not to mention the source of extraordinary Madeiras).

Verdejo is also enjoying a bit of a resurgence in other parts of the world, including California. But there’s nothing like Verdejo from Rueda.

It’s not just Rueda’s soil and climate, but the continuous arc of time in which Verdejo vines have grown there. Those vines originated in North Africa but made it to Rueda by the 11th century, thanks to migrant Mozarabs: unconverted Christians who lived under Arab rule in the Andalusian caliphate. Time matters.

The best Verdejos I’ve ever drunk are from very, very, very old vines, some of which (the Pie Franco) are ungrafted, having escaped the phylloxera louse in the late 19th century.

Past and present enjoy a productive and interesting relationship in Rueda Verdejo. For most of its long history, this grape was used to make an oxidized, Sherry-like wine. It’s only in the past 35 or so years that a cleaner and more modern reductive style (where oxygen is severely restricted in the winemaking) has emerged.

That’s all for the good, because, well, we clean moderns like clean, modern wine. Freshness, acidity, vigor, juiciness, buoyancy, verve. These are the traits of a successful white wine in our times, as lovers of New Zealand Sauvignon Blanc, Sancerre, Grüner Veltliner and Pinot Grigio well know.

Indeed, flavor-wise your closest reference point will likely be Sauvignon Blanc. Assertive, intensely citric, sometimes grassy and usually quite mineral, good Verdejo carries the energy and flavor profile of a Touraine Sauvignon Blanc, but it points in more directions. And very good Verdejo does what you like Marlborough Sauvignon Blanc for: the boom, the pow, the grab you by the collar.

For either of these comparisons, it’s no contest budget-wise: If I were a math guy, I’d say you get roughly 150 percent more complexity, dollar to dollar, in a Rueda Verdejo than in Sauvignon Blanc from Touraine, New Zealand, Sancerre or Pouilly-Fumé.

Anyway, even when Sauvignon Blanc is thrilling, it’s almost always the same kind of thrilling; not so with Verdejo. In texture and overall character, then, move to a comparison with Grüner Veltliner. The Rueda wines are that flexible with food, that varied in expression and, at the upper levels, that long in the finish and capable of aging several years into nut-crusted magnificence.

Both of my straw-men examples are, generally speaking, green. The fruits in Sauvignon Blanc and Grüner taste green, and they’re surrounded with leafy and herbal notes. Verdejo’s fruits are orange-yellow: ripe pears, oranges. (I like orange fruits more than green ones. If your favorite apple is a Granny Smith, maybe stick with Sauvignon Blanc.)

Rueda Verdejo can play the pinpoint fresh wine game, and more than hold its own. But that reductive game isn’t the only one in town, and I’m happy that there are a few contemporary Verdejos available stateside that retain a perceptible vestige of the traditional style.

With oxygen invited into the process, such wines are less contained, less predictable.

The fruity vibrancy is fleshed out with tones of medium-dark honey, spices, marzipan, nuts. And Verdejo’s naturally full body is provided more space to roam, spreading and smoothing as it goes.

A couple of caveat-emptor notes: With an eye toward prestige and power, some Rueda producers age their Verdejo in oak casks.

Though the grapes themselves have the stuffing for such treatment, I’ve never tasted a successful example.

Also, a wine from Rueda must contain 50 percent Verdejo, but the rest can come from Sauvignon Blanc and Viura (sometimes called Macabeo). Even wines labeled “Rueda Verdejo” can have 15 percent of the other grapes. All the wines listed below are unoaked, and 100 percent Verdejo.

Lastly, please note the vintages listed. Taken together, these three wines, though surely distinct in any particular year, offer the rare chance to dip a foot into the river of time.

Erre de Herrero Verdejo 2013, $15. The youngest wine on this list, but from vineyards where most of the vines are at least 60 years old, and it’s got scary-level ambition. Intensely mineral and even muscular, with herbal, fennel and forested qualities in spades.

About a half-hour out of the fridge and after the cork has been pulled, its prodigious structure comes out. And at around that time, you’ll also notice an almost buttery quality, and the balance of an expertly made margarita with both salt and sugar rimming the glass.

Anthropomorphism: A 20-year-old man, smart and ripped, with a lot to say.

Vinedos de Nieva Verdejo 2012, $15. This is a more floral, delicate wine than the Erre de Herrero, and its fruit composition strikes me as more melony and even tropical.

The acidity is a bit toned down, allowing those softer flavor components to shine.

Anthropomorphism: The 22-year-old woman in a flowing dress who quiets down the 20-year-old man so that they can live happily ever after.

(Buyer’s alert: The same bodega produces a Verdejo Pie Franco, not available in Maine, from 150-plus-year-old ungrafted vines in a single vineyard. I bought a bottle of the 2012 in New York last month, for $21, and remain, six weeks after drinking it, under its expansive spell.)

Vidal + Vidal Verdejo 2011, $15. This single-vineyard wine, with a subtitle of “cepas muy viejas” (very old vines), is the old soul of Verdejo. (Its only nod to modernity is a stupid artificial cork, which I pray they replace with real cork or Stelvin for the next vintage.)

That soul gives us vigorous mineral tones and flavors we’d never expect from the fresher expressions: candied bitter orange rind, hazelnuts, dried porcini, fontina cheese, the faintest hint of dry Sherry.

It’s the only Verdejo I’ve tasted that I’d call earthy.

Like the earth itself, it tastes as if it has infinite time at its disposal. It points downward, to the substructure. Drink this, not for the upward thrust of acidity and zip but to go down and back.

Anthropomorphism: An old Castillian, broad hat half-shielding him from the sun, smiling half at you and half to himself.

Joe Appel works at Rosemont Market. He can be reached at:

soulofwine.appel@gmail.com