Backyard grillers who want to add a gourmet touch to their meal — sans calories — can look to wood.

"Wood-fired is a more complex, interesting flavor, for sure," said John Seuferling, a barbecue competitor who serves on the board of directors for the Pacific Northwest Barbecue Association (www.pnwba.com). "A whole other flavor dimension comes into the picture."

Charcoal provides a consistent, high heat but "the flavor-producing components are burnt out of the wood when it's kilned to make charcoal," explains Steven Raichlen in "How to Grill: The Complete Illustrated Book of Barbecue Techniques."

"We've seen a huge increase in wood sales," said Donna Myers, spokesperson for the Hearth, Patio & Barbecue Association.

Shipments of cooking woods almost tripled in the past 10 years, jumping from about 13.5 million pounds in 1993 to nearly 38.5 million last year, according to the barbecue association. The largest increase came in wood chunks, with shipments soaring from 5 million pounds to 26 million in the past decade. Myers attributes this to the growing popularity of wood as a primary fuel instead of charcoal briquettes.

Mesquite and hickory are the most popular types of wood, followed by fruitwoods such as apple and cherry. Other choices include maple, alder, pecan and oak.

For smoke, another option is wood pellets made from compressed sawdust of different woods. BBQr's Delight, for example, makes sassafras and Jack Daniel's pellets (from mellowing charcoal used to make the whiskey).

Cooking woods are now widely available in retail and grocery stores, especially those that carry a variety of barbecue items.

"People want to eat at home in their back yard like they do in five-star restaurants," said Raymond Morris, sales manager for Linda's Cooking Woods, which supplies Yakima-area woods to Seattle restaurants and retail stores.

More than three-quarters of households own a barbecue; two-thirds of grill owners cook on a gas grill while about half boast a charcoal grill, according to the barbecue association. Nearly one out of five owns both.

Many new gas grills now feature smoke boxes; using wood can give gas cooking extra oomph. "There's a perception that you get better flavor from charcoal than gas," Myers said. "But if you put a spice rub on meat and cook it over hickory smoke, you can't tell whether it was cooked on gas or charcoal."

Enthusiasts credit cooking shows and the popularity of ethnic foods with creating outdoor cooks who are more sophisticated and willing to experiment. "Americans like really intense flavor for all things," Myers said.

Ten years ago, the only foods gracing most grills were chicken, steak, hamburgers and hot dogs. Now folks are grilling fish, vegetables and pizza. "We see everything in the world on the grill now," Myers said. "People have become more versatile."

That willingness to try new things helped spark more interest in cooking with wood, either with smaller chips for smoke along with charcoal/gas or by replacing briquettes entirely with larger wood chunks. Cooking over wood chunks can require a little more maintenance as wood tends to burn hotter than charcoal.

Fresh wood with a high-moisture content provides the best heat and flavor, Morris said. Others recommend wood that's been seasoned for at least a year to avoid the sap of green wood.

"The same wood used with different foods can taste completely different," Myers said. Some cooks like to mix wood or flavored pellets, such as orange with hickory, for "double flavor," she noted.

In addition to taste, "hickory gives a nice, golden color," said Seuferling, a West Seattle resident who teaches barbecue classes. "The meat looks like it's bronzed."

Seuferling likes to cook chicken and seafood with cherry wood for its mild, sweet flavor and mixes apple and hickory for ribs. "With beef, I go for mesquite or hickory. That kind of meat can handle the stronger smoke flavor."

Grilled food such as chicken breasts or fish are cooked so quickly they might not absorb more subtle smoke flavors such as apple. Nonetheless, the most common beginner mistake is overdoing the smoke, which makes food taste bitter. "A little bit of flavor goes a long way," Morris said. "Too much can ruin the food by overpowering it. It's trial and error."

A handful of wood chips should suffice: "You don't need to go ballistic and dump in the whole bag," Seuferling said.

Myers recommends soaking chips in water for an hour to get good smoke; Seuferling says he doesn't bother when putting them on charcoal. Wood pellets don't need soaking but go into a foil pouch.

With a charcoal kettle grill, folks can throw wood chips (for quick grilling) or chunks (for longer cooking) directly on briquettes for smoke or use a package of wood chunks as fuel.

For some gas grills without a designated smoking drawer, soaked and drained chips can go into a packet of heavy foil poked with holes or a small aluminum pan. For their grills, Weber suggests setting it under the grate on top of the bars over a burner. For others, consult with the manufacturer so that you don't damage the grill.

Preheat the barbecue for five or 10 minutes until the wood starts smoking. It's important to contain the wood as burning the wood directly can create ashes that plug up the propane jets.

With charcoal, even the starting technique can make a difference in taste, some say. "Lighter fluid is taboo with our people," Seuferling said. "It definitely gets a petroleum flavor into your cooking." Instead, he uses a chimney starter to light the charcoal with newspaper or a firestarter cube. A chimney starter can also be used to light hardwood chunks.

Once folks get the hang of using wood to grill food, they might try traditional barbecue, which is cooked "low and slow" for hours, often with wood.

"For some people, a barbecue is dad's charred hockey puck of a hamburger," Seuferling said. "But there is another world out there."

Stephanie Dunnewind: sdunnewind@seattletimes.com.