The seductive smell of cocoa beans roasting, venting from a nondescript factory on West Kinzie Street, is how many Chicagoans know the Blommer Chocolate Co. — if we know it at all.

Three-quarters of a century after Blommer's founding here, its sweet scent still comes with an air of mystery.

A Chicago-based, family-run business, Blommer is not just tightly held but tightly protective, particularly when it comes to its operations and even the identity of its clients. Those of us who enjoy chocolate are quite likely Blommer consumers. But its customers are the brand-name companies it supplies with cocoa and chocolate products, coatings and other ingredients, and the customers come first.

There is a small factory store, where the public can buy treats made with Blommer products, and outsiders rarely get any closer. Even when the company broke precedent and staged a small media event at the plant a couple of years ago to tout its long-standing commitment to cocoa crop sustainability, photography was banned.

But to mark the 75 years since Henry Blommer and two brothers launched North America's oldest and largest independent cocoa bean processor, grandsons Peter and Rick Blommer — cousins and today's co-chairmen — thought it time to briefly open up in acknowledgment of all that their family, employees and business partners have built.

"We just want to stop at this anniversary and say, 'Look at where we've come from,'" said Peter, the chief operating officer, whose father, Henry Jr., retains the title of chief executive though is no longer active in daily operations.

The timeworn joke is that Blommer's factory isn't like that of the fictional but similarly private candymaker Willy Wonka, in that there's no chocolate river. "At least not on purpose," said Rick, who oversees global operations.

It's closer to the workplace in which Lucy Ricardo and Ethel Mertz famously struggled, though the lines move faster and what comes off them is never closer to a candy ready for consumption than a chocolate chip.

Near specialized machinery are pallets piled with stacks of newly filled sacks awaiting shipment. Workers wear hairnets, protective eyewear and lab coats. It's clean and smells great, but it looks a lot like plenty of other factories.

And it was nearly someone else's.

"We almost lost this business back in 1992," Peter said, recalling a tense 18-month stretch after Henry Sr.'s death.

Relatives who controlled 50 percent of the company cashed out, selling to giant rival Cargill, itself a family-controlled business. Cargill hungrily eyed the rest. But while the Minnesota-based commodities and food-processing multinational tested the Blommers still connected to the business, the public tug of war ultimately strengthened their resolve.

When Cargill realized it would be unable to pry loose any more shares, the interlopers retreated and sold to the Blommers.

"That was an inflection point for us where we as a family, including those of us in the third generation just getting into the business, had to think about whether … we wanted to fight for something that not only meant something to us sentimentally but had growth prospects," Peter said. "We've grown sevenfold since then, and we're positioned for more growth ahead."

The Cargill conflict spurred the Blommers to seek out expert counsel on running a family business. They emerged from the fight with new purpose and new protocols concerning what the company would expect of family members and what family members could expect of the company.

Criteria were established for adding family members who might wish to come aboard, with requisites including a four-year college degree, five years of work experience and a skill set that the company needs. The company has two classes of stock, and family shares can throw off enough cash to discourage the Blommers not directly involved from agitating to break the ownership structure.

"We had no lockup or buy-sell arrangements, and now we do," Peter said. "It's really nice when you learn a lesson, it ends up with you getting a second chance."

There are at present seven family members connected to the business. Peter's dad is the lone second-generation Blommer company person. Five of six third-generation family members are officers, including Peter, who primarily works out of the Pennsylvania office. Rick and Peter Drake, who's vice president of sales, are here in Chicago.

Yet another generation of Blommers is coming of age, but their parents stress that they should never feel entitled or obligated to assume a role in the family business. They have to want it. They have to earn it. Ownership is not necessarily tied to management.

John Ward, clinical professor of family enterprise at Northwestern University's Kellogg School of Management and co-director of the Center for Family Enterprises, said he only knows Blommer Chocolate from "the aroma when I come off the Kennedy" Expressway. But, generally speaking, getting this far bodes well for the company.

"It was actually the rags-to-riches-to-rags cliche that motivated my interest in family businesses," Ward said. "It seemed so fatalistic. ... It can be true, and statistically it is true, that not that many family businesses make it past the third or fourth generation, but those that make it to the third or fourth generation often sustain themselves very well."

Although this is the third generation of Blommers running their company, it is the fourth generation in the chocolate business. Henry Sr.'s father was a partner in Milwaukee's Ambrosia Chocolate (now part of Illinois-based Archer Daniels Midland). Henry was working there when he and his brothers decided in 1939 to strike out on their own in Chicago, long a major hub for commercial bakeries and candymakers.

Their routine was to take the train down from Milwaukee on Mondays, sleeping on cots between factory pallets, and return home Fridays. Peter and Rick Blommer recall spending nights at the factory themselves when they were younger.

"Most of us worked extensively during Christmas breaks and summers, doing some of the dirtiest jobs," said Peter, who picked up an MBA and worked on Wall Street and then for Dole Food Co. before returning to the family business full time. "Having been grounded in the hard, hot work that's done out on the factory floor creates a real appreciation for everyone that we have working for us in the plants and given us a real hands-on knowledge of the operations."