It wasn’t all that long ago that Americans seeking liquid refreshment of the nonalcoholic variety were confronted with a single, basic, binary choice: Coke or Pepsi? But those days are gone and unlikely to return. Walk past a group of teens or 20-somethings on a hot day in your neighborhood and they’re more likely to be nursing or chugging water, tea, coffee, energy drinks, or juice than an Orange Crush, Dr Pepper, Mr. Pibb, Mountain Dew, Squirt, or Sprite.

As the New York Times noted in 2015, “Soda consumption … [which] rocketed from the 1960s through 1990s, is now experiencing a serious and sustained decline.” It turns out that 2015 was the 11th consecutive year in which carbonated soft drink sales declined in the U.S., according to Beverage Digest. Total volume that year was reportedly down 1.2 percent, exceeding 2014’s 0.9 percent decline, as annual per capita consumption dropped to its lowest level since 1985. Talk about fizzling out.

There are plenty of explanations for this wholesale shift in consumer preference, from speculation about possible (though largely unconfirmed) health risks associated with some artificial sweeteners to the high-calorie content of many regular (non-diet) sodas.

One thing that’s abundantly clear from where we sit at CCD Innovation is that the turn away from traditional sodas is at least partially due to younger consumers’ overall diminished interest in sweetness as a predominant flavor characteristic. Now more than ever, we look to mixologists—the new Iron Chefs of the culinary world—for clues on how to develop nonalcoholic beverages that boast more complex, balanced, and nuanced flavor profiles. And these days, those crafty mixmasters are pointing to four particular flavor characteristics as alternatives to sugars and sugar substitutes, which tend to be a bit heavy-handed and monochromatic.

First among these intriguing options is bitter—an acquired taste, to be sure. But the prevalence of heavily hopped craft beers—as well as coffees, teas, and artisanal cocktails that include grapefruit, chicory, bitter lemon, bergamot, and smoke—suggests that this is an area ripe for further exploration. Indeed, smoky flavors seem to have taken on a life of their own recently, what with mezcal bars popping up in hip urban enclaves like Chicago’s Logan Square, and single-malt scotches so popular that producers can’t keep up with demand. Whether imparted via liquid smoke or with an actual smoking gun—a hair dryer–like device that burns wood chips and produces smoke that can be piped into a cocktail, a soda, or even a juice beverage—smokiness is catching on in a big way.

Sour is another hot trend in the beverage world today, and with good reason. While critics may assign qualities such as tartness, astringency, or acridity to sour drinks, these naysayers often fail to appreciate just how delectable and interesting sour flavors can be when balanced with other ingredients. Passionfruit, lime, tart cherry, quince, tamarind, yuzu, and pickle brine represent just a few of the elements mixologists and craft beverage makers are incorporating into their wares. What’s more, the past few years have seen a re-emergence of shrubs—old-fashioned soft drinks made with vinegar and fruit, which were particularly popular in Colonial times, when refrigeration was really a nonexistent commodity and room temperature was as chilly as your preferred quaff was likely to get. With shrubs, the acid from the vinegar makes for a refreshing drink that doesn’t require ice. In a similar vein, kombucha—a category of fermented infusion-based beverages—is now on tap in many restaurants and bars, largely due to its reputed (though still unproven) health benefits.

Botanical flavors are—ahem!—blooming as well, with their attendant softness, distinctive perfumes, and nostalgic associations. From chamomile to jasmine, rose to lavender, and cilantro to thyme, juniper, violet, elderflower, and sage, we’re now seeing these bases being used to liven up flavored waters, cocktails, and even coffee beverages.

On the other end of the sensory spectrum is spicy heat, which is turning up everywhere in the beverage world. It’s all the rage in craft sodas, thanks to millennials’ passion for bold flavors. More classic spices such as clove, nutmeg, and chai are taking a back seat as the likes of piri piri, chilies, habanero, cayenne, sriracha, and other hot commodities are being used as both condiments sprinkled on top of beverages and ingredients that are incorporated into the body of the beverage. In both cases, the effect can be pleasingly piquant and exciting.

So even though our time-honored pops, sodas, and other sweet beverages aren’t going away entirely, it behooves today’s menu developers to take a closer look at more complex alternatives to simple sweetness. Clever experimentation with some or all of the foregoing suggestions might just yield the beverage world’s next big thing.

This story originally appeared in QSR’s February 2017 issue with the title “So Much for Sweet.”