Lynsi Torres (Bob Johnson/Bloomberg via Getty Images)Such service has helped In-N-Out create a rabid fan base — and make Lynsi Torres, the chain’s 30-year-old owner and president, one of the youngest female billionaires on Earth. New store openings often resemble product releases from Apple Inc. (AAPL), with customers lined up hours in advance. City officials plead with the Irvine, California-based company to open restaurants in their municipalities.

“They have done a fantastic job of building and maintaining a kind of cult following,” said Bob Goldin, executive vice president of Chicago-based food industry research firm Technomic Inc. “Someone would love to buy them.”

That someone includes billionaire investor Warren Buffett, who told a group of visiting business students in 2005 that he’d like to own the chain, according to an account of the meeting on the UCLA Anderson School of Management website.

The thrice-married Torres has watched her family expand In- N-Out from a single drive-through hamburger stand founded in 1948 in Baldwin Park by her grandparents, Harry and Esther Snyder, into a fast-food empire worth more than $1 billion, according to the Bloomberg Billionaires Index.

Biblical Citations

Famous for its Double-Double cheeseburgers, fresh ingredients and discreet biblical citations on its cups and food wrappers, In-N-Out has almost 280 units in five states. The closely held company had sales of about $625 million in 2012, after applying a five-year compound annual growth rate of 4.6 percent to industry trade magazine Nation’s Restaurant News’s 2011 sales estimate of $596 million.

In-N-Out is valued at about $1.1 billion, according to the Bloomberg ranking, based on the average price-to-earnings, enterprise value-to-sales and enterprise value-to-earnings before interest, taxes, depreciation and amortization multiples of five publicly traded peers: Yum! Brands Inc. (YUM), Jack in the Box Inc., Wendy’s Co. (WEN), Sonic Corp. (SONC) and McDonald’s Corp. (MCD) Enterprise value is defined as market capitalization plus total debt minus cash.

One private equity executive who invests in the food and restaurant industry said the operation could be valued at more than $2 billion, based on its productivity per unit, profitability and potential for expansion. The person asked not to be identified because he is not authorized to speak about his company’s potential investments.

Plane Crash

“In-N-Out Burger is a private company and this valuation of the company is nothing more than speculation based on estimates from people with no knowledge of In-N-Out’s financials, which are and always have been private,” Carl Van Fleet, the company’s vice president of planning and development, said in an e-mailed statement.

Torres, who has never appeared on an international wealth ranking and declined to comment for this article, came to control In-N-Out after several family deaths. When her grandfather Harry died in 1976, his second son, Rich, took over as company president and expanded the chain to 93 restaurants from 18.

Torres’s father, Harry Guy Snyder, became chief executive following Rich’s 1993 death in a plane crash at age 41. The chain expanded to 140 locations under Guy, who inherited his father’s passion for drag racing.

Ford Cobra

When he died of a prescription drug overdose at age 49 in 1999, Snyder’s estate included 27 cars and other vehicles, including a 1965 Ford Cobra and a pair of 1960’s-era Dodge Dart muscle cars, according to his will.

Torres’s grandmother Esther — Harry’s widow — maintained control of the company until her death in 2006 at age 86. When she died, Torres was the sole family heir. She now controls the company through a trust that gave her half ownership when she turned 30 last year, and will give her full control when she turns 35. The company has no other owners, according to an Arizona state corporation commission filing.

Few in the restaurant industry have met or know much about the hamburger heiress.

“I have no clue about her,” said Janet Lowder, a Rancho Palos Verdes, California, restaurant consultant, who said she was one of the few people to extract the company’s internal finances from Esther Snyder in the 1980’s for industry-wide surveys. “I was even surprised there was a granddaughter.”

Limited Menu

Torres has little formal management training and no college degree. The company was structured to carry on after the demise of its founders, according to a 2003 Harvard Business School case study. In-N-Out has never franchised to outside operators, the Harvard researchers said, giving up a low-cost revenue stream in exchange for maintaining quality control.

In a 2005 article in the Harvard Business Review, Boston- based Bain & Co. consultants Mark Gottfredson and Keith Aspinall attributed the company’s estimated 20 percent profit margins at the time to the simplicity of its limited menu. Contrast that with competitors such as Oak Brook, Illinois-based McDonald’s and Miami-based Burger King Worldwide Inc. (BKW), which regularly change their food offerings.

“Other chains seem to change positions as often as they change their underwear,” said Bob Sandelman, chief executive officer of San Clemente, California-based food industry researcher Sandelman & Associates.

Calculated Growth’

Butchers carve fresh beef chuck delivered daily to the company’s distribution facility in Baldwin Park, where hamburger patties leave for restaurants on 18-wheeled refrigerated trucks outfitted with over-sized tires so the In-N-Out logo can be better seen on the highway. The company only expands as far as its trucks can travel in a day, either from the Baldwin Park complex or a newer facility in Dallas, the only two places where the company makes hamburger patties.

In-N-Out expanded to Texas in 2011, after building a warehouse and the patty facility. There are now 16 units in the state. Conrad Lyon, a Los Angeles-based senior restaurants analyst for B. Riley Caris, said additional expansion will continue to be gradual.

“I would expect slow, calculated growth,” he said in a phone interview. “To outsiders the company’s growth out West likely appears sluggish. However, it was management carefully leveraging its brand, real estate and distribution. As a private company-owned system, In-N-Out has the luxury of calling the shots to replicate its success without succumbing to potentially detrimental outside influences.”

Complaints, Allegations

The company’s pace of expansion was one of the issues at stake in an exchange of lawsuits in 2006 between Torres, In-N- Out executives and Richard Boyd, the company’s former vice president of real estate and development. Boyd was one of two trustees overseeing the trust that controls the company’s stock on behalf of Torres.

Among other allegations filed in California state court in Los Angeles, Boyd claimed Torres and Mark Taylor — her brother- in-law from a half-sister — conspired to remove Esther Snyder from the company to gain control of In-N-Out. He filed a separate petition with the probate court seeking to prevent Torres from removing him as a trustee.

Torres denied the allegations in both a formal answer to Boyd’s complaint and a 2006 letter to the editor published in the Los Angeles Times, in which she said she only had “minimal involvement” in the company’s business decisions, and didn’t favor rapid expansion.

16 Bathrooms

The company in turn filed a breach of contract lawsuit against Boyd, alleging fraud and embezzlement in connection to Boyd’s relationship to one of In-N-Out’s outside construction firms. Boyd’s lawyer, Philip Heller of Fagelbaum & Heller LLP in Los Angeles, said all the litigation was dismissed following a confidential settlement. Boyd resigned from the company and the trust.

“They were all in the end amicably resolved,” Heller said.

Since then, Torres has refused most interview requests, even by author Stacy Perman, who wrote a 352-page book about In- N-Out in 2009. Torres asked to set up a meeting with the author after the book’s publication, but it never occurred, Perman wrote in an afterword to the 2010 paperback edition.

Torres popped up in real-estate blogs in September, after buying a $17.4 million, 16,600-square-foot mansion in the wealthy enclave of Bradbury, California, in the foothills of the San Gabriel Mountains. A Realtor.com listing for the house described it as having seven bedrooms, 16 bathrooms, a pool, a tennis court and other amenities.

Drag Racing

Torres is one of almost 90 hidden billionaires discovered by Bloomberg News since the debut of the Bloomberg Billionaires Index in March 2012. Among them: Dirce Camargo, the richest woman in Brazil, and Elaine Marshall, the fourth-richest woman in America.

Like Camargo and Marshall, Torres maintains a low profile. Her most visible presence has been on the drag strip. She competes in the National Hot Rod Association’s Super Gas and Top Sportsman Division 7 categories, alternating between a 1970 Plymouth Barracuda and a 1984 Chevrolet Camaro, according to NHRA results. Her third husband, Val Torres Jr., is also a race- car driver.

Whether the mother of twins will maintain ownership in the chain after she gains full control in five years is uncertain, said John Gordon, founder of San Diego-based restaurant consultant Pacific Management Consulting Group.

“It’s an open question whether she may have different feelings later,” said Gordon. “Like most kids, or second or third generations of a very wealthy family, I don’t know that she has restaurant blood in her veins, or if she’s a trust fund baby.”