When Carl Coates, a 47-year-old father and high-school administrator living in Chicago, came into a little extra cash last year, he decided to make what seemed to him like a smart investment.

He bought a cow. Well, half a cow really.

He split the cow with a neighbor friend — their girls go to the same elementary school — who shares Coates’ passion for backyard grilling. Cows, on average, cost around $2,000. (Coates can’t recall what they paid. They got a deal from a farmer in Central Illinois.) That’s for a 750-pound carcass that breaks down to 490 pounds of boneless cow meat.

Coates ended up with half of that — a couple hundred pounds of ground beef and cuts of steaks, roast, ribs, brisket and tenderloin — and he admits he wasn’t entirely prepared for what showed up on his front porch.

“That’s a lot of meat,” he says. “We have a stand-up freezer in the basement that we were using for breast milk. The kids are off the teat now, so it’s become storage for cow meat.”

Coates wasn’t always an obsessive grill hobbyist. Though he was born and raised in Texas, one of the undisputed grilling capitals of the world, his parents were mostly indifferent to barbecue. It wasn’t until he moved to Chicago a decade ago that he bought his first grill, a Weber Smokey Joe compact enough to fit in the back stairwell of his condo. After getting married and having his first child, Coates graduated to a Weber Performer Deluxe, a 22-inch freestanding charcoal grill that runs for around $400. Every year, his fascination with grilling has grown more intense.

“If I get a brisket, I’ll want to trim it myself,” he says. “I’ve started spatchcocking my chickens. All it takes is a good knife and some muscle power.”

He bought his first smoker a few years ago and a second smoker not long after. “I want every new grilling gadget that comes out,” he laughs. “I’ve become one of those guys.”

You probably know “one of those guys”; a friend or neighbor or relative who takes his or her backyard grilling very seriously. They don’t just have a standard charcoal grill, which gets rolled out a few times for summer holidays. They’ve got a high-tech grill with all the bells and whistles, every fancy grilling gadget that money can buy and strong opinions about wood cooking versus gas.

They’re not just passionate about grilling, they’re downright fanatical. They’re people like Nathan Myhrvold, who retired as Microsoft’s resident tech visionary to spend more time grilling, and Robert Wright, a Fresno, Calif., man who ran back into a burning house to save his recently grilled rack of ribs in 2015.

There aren’t more people using grills than 20 or even 30 years ago. The Hearth, Patio & Barbecue Association (HPBA) conducts an annual survey of the grilling industry, and they say the numbers haven’t fluctuated significantly in decades, since they started monitoring consumer trends. In 2017, 70 percent of American adults owned a grill or smoker, which is more or less the same findings about 20 years ago. What has changed, however, are grill sales.

Over the past five years, revenue for US grill manufacturers — led by Weber-Stephen Products, maker of the iconic Weber grills — has been on the rise. Because consumers are more likely to purchase new grills more regularly, sales have climbed an average of 2.8% every year, according to research firm IBISWorld with an industry-wide revenue of an estimated $6.6 billion last year. That number is expected to reach $7.2 billion by 2022.

What customers are paying for would shock their grilling enthusiast fathers and grandfathers.

Modern grills come with features like three or more burners, infrared heating for crisper searing, halogen lights for nighttime grilling, up to 75,000 BTUs and even voice-command settings.

The 42-inch Lynx SmartGrill ($9,500) can be operated remotely with a smartphone app and will send you text alerts when it’s time to flip your meat. Then there’s the much-coveted Kalamazoo Hybrid Fire Grill, which runs for $27,295. (The starting price for a 2018 Honda CR-V is $25,125.) For the money, you can reach internal temperatures of 1,000 degrees Fahrenheit — you only need around 325 degrees to cook a 120-pound pig — and laser-cut surfaces capable of monogramming steaks and burgers with your initials.

A rep for Kalamazoo Outdoor Gourmet says that domestic sales for the hybrid grill are stronger than ever, up 18 percent from last year. (They declined to share exact figures.)

Steven Raichlen, the award-winning grill master (he’s been called the “Julia Child of BBQ”) and author of “The Barbecue! Bible” and the newly released “Project Fire,” thinks the trend may be fueled by increased international travel. “Americans are traveling a lot more now than 20 years ago,” he says. “They’ve eaten sate in Thailand, bistecca alla Fiorentina in Italy and jerk in Jamaica. We want to reproduce those flavors at home.”

Social media may also be a factor, says Ben Eisendrath, the president of Grillworks, a manufacturer of high-end, wood-burning grills that run between $3,500 and $20,000 — with sales in the millions and an average growth of 40 percent annually. “People have started to see the way people grill outside the States,” he says. “You’re not just seeing what your neighbor is grilling, you’re seeing what they’re grilling in Argentina, in Uruguay, in rural parts of France and Spain.”

He’s had some customers — including a few professional chefs who once scoffed at grilling — call him and say, “I just got back from Spain and I’ve got the religion now.”

The biggest change of today’s grillers versus their forefathers is that grilling has transcended a mere weekend hobby. In HPBA’s 2017 consumer survey, more than half of respondents claimed that they grilled not just for flavor but as a “lifestyle choice.” Raichlen isn’t surprised by this.

“When you simmer a stew, no one gathers around the stove to watch it,” he says. “But when you grill, you’re the center of attention. Everyone gathers around, and the act of cooking becomes a party.”

The majority of students who attend his Barbecue University classes aren’t professional chefs, but they aren’t exactly amateurs either. Most have at least three grills at home and several smokers, and they’re eager to learn new offbeat techniques, like cavemanning (grilling on the embers), hay or leaf grilling and “grilling the whole meal, including cocktails and dessert,” Raichlen says.

As BBQ fiend Coates in Chicago indicates, there’s also been an influx of in-bulk meat purchases because of home grilling. Sales of fresh grass-fed beef, the kind preferred by grilling connoisseurs, jumped from $17 million in 2012 to $272 million just four years later, according to Nielsen data. Omaha Steaks, the premier mail-order steak company, has seen a 50 percent growth in slow cooker and skillet meals, and increased demand for their King Cut steaks, including a 72-ounce steak for $120 — the same size, coincidentally, of the steaks that visitors are infamously “challenged” to finish at the Big Texan Steak Ranch in Amarillo, Texas.

Porter Road, a Nashville butcher shop that’s sold meat locally since 2011, went online this year and saw their sales jump to six figures just a few months into their launch. “There are more meat nerds out there than we thought,” says James Peisker, one of two trained chef co-founders. “The average online customer is spending about $100 per order. Butcher’s cuts like teres major, tri-tips, cap steaks, picanhas, flat iron steaks and Denver steaks are in high demand and often some of the first cuts to sell on a daily basis.”

Coates says it may be flavor that got him into grilling, but it’s the lifestyle that’s turned him into a grilling devotee. “I was listening to this podcast about the making of “Jaws,” and they talked about how Steven Spielberg was more interested in an audience’s reaction to his movies than the movie itself,” he says. “I’m in no way trying to compare myself to Spielberg, but I understand that feeling. The joy isn’t just what I’m tasting, it’s having people over and grilling something for them and seeing their reactions.”

He’s not planning on investing in another cow in the near future, but he does have a grilling wishlist. “I want to get one of those oil drum BBQ smokers,” he says. “A big 55-gallon one that could smoke a whole pig. I’m looking out at our patio right now, and there’s a kiddie pool out there. And all I can think is, ‘Y’know, if I got rid of that pool, there’d be plenty of room for the oil drum.’ ”

BBQ: A SHORT HISTORY