WAY BACK in the Paleolithic era of American Wine Drinking — a time coinciding with leisure suits, fern bars and the Carter administration — sweet wines ruled. People loved their cheap Mateus and Blue Nun and Andre Cold Duck. Then, all of a sudden, everyone got all sophisticated and savvy and demonstrated this by eschewing sweet for dry. Basically, you were a moron or a rube if you liked sweet wine.

Or at least that's what we were told. I know something like this happened in our home when I was growing up. As a kid, I vaguely remember a moment when my parents started opening bottles of Napa Valley cabernet sauvignon and chardonnay. As I got older, I was made to understand that sweet wines were vaguely embarrassing. Years later, as I delved deeper into wine, I realized of course that all those bottles of Sutter Home and Kendall Jackson still had just a little residual sugar.

It's an adage in the wine business: Americans talk dry but drink sweet. Given the chance, most Americans would fall back on the sweetness that was a mainstay of their childhoods, when they consumed sugary juice boxes and sodas and candy. The main reason most wine lovers allegedly don't drink sweet is over the past few decades they've "trained their palates" (i.e. been bullied by wine snobs) to appreciate dry. That's the theory of some wine professionals anyway.

In any case, things change. Lo and behold: Sweet wines are suddenly back in fashion. Hip young sommeliers are pushing sweet and off-dry wines at high-end restaurants. In wine-geek circles, Rieslings and gewurztraminers and Tokaji and sweeter styles of Madeira and sherry are all the rage. In New York, influential sommelier Paul Greico's "Summer of Riesling" — when Rieslings dominate the menu at his trendsetting East Village wine bar Terroir — is now in its fifth year.

Even more mainstream has been the out-of-nowhere popularity of sweet, fizzy, low-alcohol moscato among young wine drinkers. Moscato's sales shot up nearly 80 percent last year, and its rise is mostly credited to the world of hip-hop. Where rappers once extolled the pleasures of cognac or champagne, they now talk about sweet wine, like Drake in "I Invented Sex": "It's a celebration clap bravo/Lobster and shrimp and a glass of moscato." (Not a particularly good pairing, fyi.)

"It's like a tipping-point thing," said Michael McCaulley, managing partner at Philadelphia's Tria wine bar. "Now, sweetness is cool."

Gimme some sugar

At Tria's three locations, the staff has recently undergone a four-week training on sweet wines. Rather than trendy moscato, Tria has steered toward more complex, classic sweet wines such as Rieslings, Madeira and Sauternes. "Our sales on sweet wines have gone up tremendously," McCaulley said. Tria is selling three times as much Madeira as it did even last year.

"A few years ago, if you said, 'Dude, I'm drinking a Sauternes or a Madeira,' people would look at you like you were an alien. Now you're totally hip," he said.

Rappers and sommeliers aside, one of the main reasons for the resurgence of sweet wine has been the realization that off-dry and sweet wines pair better with the sorts of food that contemporary diners enjoy, such as spicier Asian dishes. "Bone-dry wines aren't necessarily better with food," McCaulley said. For instance, with Tria's focus on cheese, which is inherently salty, off-dry and sweet wines often pair much better.

Rieslings offer an especially great pairing with so many foods, but for years these German wines have been a tricky proposition for Americans. One reason is the hard-to-pronounce German words on the label: all those trocken and beerenauslese … and trockenbeerenauslese. The other is the association with good ol' Blue Nun.

In reality, Riesling is not an inherently sweet wine, though there is often residual sugar. The best should have a lively acidity that balances the residual. Two watchwords to look for are kabinett and spätlese, which refer to the ripeness level of the grapes. Kabinett is less ripe than spatlese, meaning less natural sugar, but it doesn't always mean that they're less sweet. On average, though, a spätlese (pronounced SHPAYT-lay-zuh) is going to walk the fine line between sweet and acidic.

Those noble rot wines

Another, perhaps stranger, style of sweet wine that I find exciting is made from botrytized grapes, meaning they have been benevolently "infected" by so-called "noble rot." If you've never had it, yes, it sounds weird, but trust me it's delicious. The most famous types of these wines come from Sauternes, a region of famed Bordeaux, and from Tokaji, in Hungary.

"I've never met anyone who's tasted those noble rot wines and said, 'I don't like this, dude,' " said McCaulley, who almost always has one or two on the menu at Tria.

Yet these wines likely seem so foreign to most American wine drinkers. A good Sauternes or Tokaji is like ambrosia, honeyed and rich but also lively and fresh. They can age for decades, and the best are often among the most expensive wines. In centuries past, they were among the most sought-after wines in the world. It's hard to believe they ever fell out of fashion.

I was lucky enough to visit Sauternes last month while on a tasting trip to France. While at famed Chateau Guiraud, general manager Xavier Planty took gentle issue with the notion of sweet wine. "I don't like the word 'sweet.' Sweet is reductive," he said. "These wines are not just sweet. They're more complex than that."

Whether you call it sweet or something else, wines like Riesling, Sauternes, Tokaji and Madeira represent a bygone era I'm happy to see us recover. And it's an era of winemaking far, far away from the mass-market moscato that's become so popular.

As for moscato, I've never been a big fan. It's always seemed like a breakfast wine, often candy-sweet and with an alcohol level lower than many beers. If you do seek out moscato, be aware that there's a lot of low-quality crap being bottled from regions all around the world, just to keep up with demand. Stick with the stuff from Italy's Piedmont region, specifically labeled Moscato d'Asti.

Despite my tastes, I see the rise of moscato — at least in theory — as an exciting development, with more people being introduced to the pleasures of sweet wine.

Even the prestigious producers in Sauternes have taken note. In recent years, Chateau Guiraud has launched a less expensive second label, Petit Guiraud, to grab some of this emerging market. "From what we can see, the millennial generation has a sweet palate as they move into wine," said Augustin Lacaille, Guiraud's brand ambassador. "Moscato was the easiest wine for them to start with. I think this is a good thing. Eventually, the millennials will seek out more complexity.

"In Sauternes, we can say this: Thank you to Coca-Cola." 

Jason Wilson has twice won an award for Best Newspaper Food Column from the Association of Food Journalists. He is the author of "Boozehound" and editor of "The Smart Set," an online arts and culture journal at Drexel University. Follow him at twitter.com/boozecolumnist or go to jasonwilson.com.