When Ron Cooper talks about mezcal, tequila's smokier, bolder sister spirit, he searches for the right words.

Humorous. Gentle. Spiritual.

Cooper is the founder of Del Maguey, probably the best-known mezcal label in the United States. He describes the liquor with the inflection of a New Age shaman.

"One producer makes an offering to the gods before he harvests wild agave," Cooper said. "The roast is three to five days . . . and they plant a cross on top of the agave hearts. Others plant fresh flowers. Others cover it with a thorny branch to keep out the evil eye. It's such a ritual beverage."

Using mezcal and tequila in mixed drinks is the next big thing at forward-looking Valley restaurants and bars.

Perhaps it's paradoxical to call mezcal, a handmade, little-understood spirit with only a sliver of the liquor market a "big" anything.

But bartenders are going way beyond the margarita, creating complex cocktails that use the two as spicy primary ingredients.

Valley restaurants including the Mission, Cowboy Ciao and Los Sombreros have long served mezcal cocktails, but the drinks have always been also-rans to flashier margaritas.

The trendy, indoor-outdoor Canteen Modern Tequila Bar opened in October on Tempe's Mill Avenue, with 120 kinds of tequila and five kinds of mezcal. And Friday, the tiny Vitamin T food-stall-style restaurant and bar at CityScape will devote some of its limited shelf space to a handful mezcals and tequilas.

Canteen mixologist Clint Manning crafted a conscientious drink list, including the Sea Smoke - a mix of mezcal, orange liqueur, orange juice and Angostura bitters - several innovative tequila cocktails and a menu of about 20 sipping tequilas priced low at $10.

Owner Julian Wright wants Canteen to be a place where people explore tequila and mezcal. He'll host regular tastings and will detail flavor profiles on menus.

"It's about flavors and adventure," Wright said.

Now showing: Mezcal

The tequila boom in the early 2000s flooded the market with more than 1,000 brands, most from companies with massive marketing budgets. Now consumers know the difference between shooting a Jose Cuervo Gold at $15 a bottle and savoring sip-by-sip an Asombroso Anejo at almost $200.

But mezcal, with only about 150 brands, all niche, has enjoyed only word-of-mouth marketing.

Cooper describes a first sip: "There can be a lot of smoke, heat, spice and flavor. But give it a few seconds, then you're palate is tuned up."

In Manhattan's East Village, Philip Ward serves tequila and mezcal cocktails, seducing crowds and winning national nightlife awards in his close, dark Mayahuel. The Mexican restaurant and bar is named for the Aztec goddess of the agave and is the country's first tequila-and-mezcal-based cocktail bar.

Ward, Mayahuel's beverage director and co-owner, says the key to enjoying the two spirits is mixing them in balanced, savory cocktails.

Mezcal isn't a primary spirit in traditional cocktails. Oxacans sip it alone, and until the spirit became en vogue in Mexico City last year, they were the only ones sipping it at all.

So at Mayahuel, Ward developed 26 mezcal cocktails drawing from what he knew about using gin and whiskey in Prohibition-era classics.

"Last year, there might not have even been 26 drinks in the whole country with mezcal in them," Ward said.

"People are pretty open to trying tequila. But they needed to learn about mezcal. We use it in citrusy tequila drinks so they get a hint of mezcal, or they get a mezcal rinse in the glass. We gingerly turn them on to it."

In the Valley, no one has more than one or two mezcal cocktails on a menu. The tend toward the complex, appealing to adventurous, curious or thoughtful drinkers.

At the Mission in Scottsdale, bartender Michael Bunker mixes mezcal with Cointreau, lime and orange juices, cilantro and a float of fantasma puree, which is a clever name for ghost-pepper salsa. At Sanctuary Camelback Mountain, Paradise Valley bartender Jason Asher serves the El Fin, made from mezcal, chartreuse, Luxardo maraschino and lime juice.

Small quantities

It's just as well bartenders use mezcal sparingly.

It's handmade in limited quantities; good brands, single-village ones, are relatively expensive, ranging from $42 to $65 per bottle. The majority of mezcal is made as it has been for hundreds of years, with earthenware pits, horse-drawn grinders and copper or clay stills.

Todd Richman, an ambassador for Illegal Mezcal, which is made in batches so limited that bottles are numbered by hand, said making mezcal is an art.

"It's the voice of a people, true Oaxacan tradition in spirit form," he said. "Really great mezcals are made by people who have been doing it for generations. There are no pesticides, no fertilizers; you only taste the raw ingredients, the agave, fire, earth and water."

Just as wine has terroir, each mezcal's flavor varies according to the minerals in a village's water and soil. Other distinctions come from whether cinnamon, sugar or even a capon were added during distillation.

Cooper had been adventuring in Mexico for about 20 years when he started exporting mezcals.

"I went down dirt roads and started asking Mixe or Zapotec Indians where the best stuff was," he said. "I would go down these roads for four to 12 hours and would finally find a big grinding wheel in the middle of a field, and I would go find the producers. Some didn't even speak Spanish, but we gestured and we drank and we communicated."

He said he had to bring mezcal back to America because it's special, with a flavor that's almost alive, responsive to temperature, barometric pressure and elevation.

"It's a spirit that has a spirit in there. You don't find mezcal; it finds you," he said.