Stick your nose into a glass of fino sherry and you may be in for a shock. Years of enjoying the usual sorts of fruity reds and whites will not have prepared you for the wave (some may say assault) of aromas. Instead of the gentle sweetness that sherry novices may expect, what arises is bone dry, pungent and savory, almost the antithesis of sweet and fruity.

Many are bewildered by sherry. Yet those who’ve made the cognitive leap find it entrancing, full of nuance and intrigue. Like strong cheeses and other polarizing foods, sherry requires stepping over a daunting obstacle of unfamiliarity and perhaps even repulsion. Some will be thrilled, but not everybody. That’s all right. The idea behind Wine School is to explore, not to please.

As one who prizes sherry, I have from time to time fooled myself into believing that to know it is to love it. I was reminded that this was wishful thinking by the many puzzled responses from usually open-minded readers to the finos I had recommended for sampling over the last month.

“I was left after this first encounter with a quizzical feeling,” said Ali of New York, who conceded, “I wasn’t sure how open I really was to a completely unfamiliar experience.”

Rick JP of Vancouver, British Columbia, said he and his fellow tasters were “underwhelmed” after a side-by-side comparison of two of the sherries I recommended, the Gonzalez Byass Tío Pepe fino and its unfiltered sibling, the Tío Pepe En Rama. What about with food? “The sherries might have improved somewhat but not enough for any of us to deliberately choose a sherry over a different wine; any wine, really.”

Ouch!

Nonetheless, some people came closer to my own experience with fino. VSB of San Francisco tried an El Maestro Sierra fino with a complicated yet delightful-sounding dish of langoustines with sun-dried black olives, shallots, herbs and spices over fusilli, all against a musical background of “The Mandé Variations” by Toumani Diabaté. The result? “Un. Be. Lievable.”

Sherry is complicated. It’s not only different from all other wines, it’s in the middle of its own revolution, which is changing the way we understand it. It’s fortified, for one thing, meaning that neutral spirits are added to the wine after fermentation, raising the alcohol level usually to about 15 percent. But plenty of other wines are fortified, too, including port and Madeira.

What makes sherry singular is both the method by which it is blended over time and, for fino sherries in particular, the process by which it ages. The blending takes place through the solera system, in which newer wines are gradually mixed with older ones to produce a sherry encompassing many different vintages.

As finos age, a little space is left in the barrels for layers of yeast, or flor, to develop. This flor shapes the fino in almost every way, from its delicate texture to its pungent aromas and flavors, to its almost austere dryness.

People in the sherry trade often refer to this process as “biological aging.” The flor not only characterizes fino, it also affects manzanilla, a form of fino that comes only from the seaside Spanish town of Sanlúcar de Barrameda, as well as amontillado and palo cortado, sherries that start off as finos but evolve in other directions.

Another type of sherry, oloroso, ages in barrels without flor, in an oxidative environment. These oxidative sherries are likewise bone dry, but have a different, more robust character than fino, like the difference between shrimp and steak.

Much of what we know and think about fino has changed in the last 15 years or so, as the sherry trade has consolidated and changed.

After World War II, sherry evolved into a mass-market beverage. Much like the American beer industry, the trade came to be dominated by big companies that — in the name of consistency, cost-cutting and commerce — effectively denatured its product. Since the 1960s, fino sherries typically were heavily filtered until they were pale and crystal clear. This process stripped them of much of their texture and character, while rendering a somewhat sturdy beverage fragile.

But this has begun to change. As in so many other industries, sherry-making has undergone a quality revolution. The market for mass-produced sherries began to die, and the only way to attract a younger audience was to offer a better sherry, even if it cost more to produce.

One method of improving fino was to select examples of the highest quality and reduce the amount of processing. These finos, like finos of old, could be bottled unfiltered or with just the lightest filtering. They are termed en rama, or just out of the barrel.

As a straightforward example, I suggested trying two versions of one fino, the Gonzalez Byass Tío Pepe, a good mass-market fino, and the Tío Pepe En Rama, the same sherry with minimal processing.

For me, the differences were striking. The Tío Pepe was straightforward and pure, not particularly complex but with the typical fino attributes: bone dry, faintly saline with savory, nutlike flavors. Nothing wrong with it: It’s like a mass-market lager, great on a hot day for a powerful thirst. But the Tío Pepe En Rama was far more intense and textured, fresh, yeasty and peppery with an ironlike tang. It could almost be too intense.

Another element of fino that has been rediscovered is the vineyard. As with mass-market Champagnes, in which the origin of the grapes is rarely discussed, so it has been with sherry, where the notion of the terroir is said to originate in the cellar rather than in the vineyard. But occasionally you can trace a sherry back to the soil.

All finos are made from the palomino grape, but very few finos nowadays come from a single vineyard. The Valdespino Inocente fino is one of them. It’s always made from grapes grown in the chalky albariza soil of Macharnudo Alto, and one can sense this in its intense mineral aromas, along with its briny, almost olivelike flavors.

The third fino, from El Maestro Sierra, was not from a single vineyard, but it, too, was textured and complex with pungent, nutlike aromas and a wealth of saline flavors. Neither the Inocente nor the El Maestro Sierra are called en rama, but they are minimally processed and seem as if they could carry the term.

I’ve always regarded finos as versatile with food, and I loved the combination of these wines with shrimp in green sauce, and especially with an excellent split pea soup.

But quite a few readers were nonplused, finding that the finos clashed with their meals. “Tough stuff, this fino,” Dan Barron of New York said. Both he and Ali of New York paradoxically found the Tío Pepe En Rama to be less intense and less pungent than the straightforward Tío Pepe. Only when Barron sampled a manzanilla, which he found rounder and more subtle, did the possible joys of sherry reveal themselves.

Its appeal may not be immediately apparent. But as with strong cheeses, something grabs you, even if the attraction is not obvious at first. My guess is that for at least some readers who were initially unimpressed, this may not be their last fino.