Upstairs in the one-time Tacoma shoe factory, a New Zealand-made machine called the “one-shot depositing line” spits out Brown & Haley’s newest, most revolutionary confection since the invention of Almond Roca in 1923.

Roca Buttercrunch Thins.

You can find it in four versions: milk chocolate butter toffee, dark chocolate butter toffee, milk chocolate caramel, dark chocolate truffle.

After five years in research and development, the premium candy sticks in the wallet-sized packs almost certainly will rocket Brown & Haley to a higher profile in the confection market.

Don’t believe me?

Inside the factory, where longtime employees have watched the rise and fall and rise of their products’ worldwide popularity, Roca Thins have clearly caused a collective chocolate swoon never before experienced.

“This is the best candy to ever come off this line,” said Bill Young. In his 41 years at Brown & Haley, Young has made every product.

On Monday, he supervised the one-shot depositing line. He adjusted temperature gauges on the hot pots that inject 97-degree melted dark chocolate and the truffle-and-buttercrunch-and-almond-bit centers into a white plastic tray with 40 molds. An hour later, after the trays run on a conveyor through a cooling tower, workers hand-pack them into the gold trays that hold eight sticks.

“When you taste it, you’ll see. It’ll sell itself,” Young said. “We just have to get it out there.”

At the corporate reception desk, Kelli Scott, between phone calls, said factory workers build up a level of immunity to the lure of chocolate. But Roca Thins somehow broke through that immunity to become a hands-down employee favorite. She described it with words like “wicked” and “addictive.”

“They’re lethal,” she said.

I tasted one of the milk chocolate caramel Thins for the first time from the clear plastic tub Scott keeps for visitors at her desk.

Definitely, lethal. In a good way.

My favorite? The milk chocolate butter toffee. The center employs the same butter toffee crunch you’ll find in the traditional Almond Roca. But the center of a Thin measures 5 millimeters compared to the traditional 12 millimeters. The center gets two coats of a premium milk chocolate.

Without nuts and a thinner center, the new butter toffee sticks have a softer bite than the hard crunch you get from traditional Roca.

Chief Executive Officer Pierson Clair – a chocolate connoisseur with a discriminating palate and vocabulary that rivals any in the wine industry – can’t explain all of the magic behind Roca Thins.

The Thins versions with the “butter toffee down the middle are double-enrobed. When you bite into it, you get this luscious thick coating of chocolate. Then you hit the buttercrunch, and it just squishes in your mouth,” Clair said. “You get this pop of butter flavor.”

But how do you get the softer buttercrunch?

“It’s the classic Roca formulation,” he said. “Trust me, we don’t understand it. It is softer. But is it the crystal structure? Is it how it mixes with the chocolate surrounding it? We don’t know.”

But Clair knows a few things for sure, “It’s better than we dreamed. … This has extraordinary possibilities for Brown & Haley. It will be a trendsetter.”

He also predicts we’ll see copycat candies from competitors.

Roca Buttercrunch Thins proved so popular with Brown & Haley retail customers that Walgreen’s buyers begged to get the candy to its 6,500 stores ASAP. So, Brown & Haley sent its first batches this month – against the standard industry practice of releasing new confections during the October-January candy season.

Now, Bartell, QFC and most other regional retailers have called for the product.

“We have this little problem of not wanting to be in the marketplace with the Thins during summer. But people want it,” Clair said.

The rush to fill unanticipated orders comes as a sweet consequence from years of research and testing of chocolate blends and center combinations.

“Five years ago I decided we needed soft Roca,” Clair said.

The first attempt used a bakery to bake a log of ground Roca butter toffee, coated it in chocolate and almonds.

Test consumers thought it tasted more like a cookie than traditional butter-flavored Roca, yet they liked the softer texture.

“But we really wanted that traditional butter flavor,” Clair said. “We kept working on it.”

The company went through 35 milk chocolate blends before it found one that, when toasted, mixed in the mouth smoothly with the buttercrunch.

Then Mark Greenhall, the company’s chief sales and marketing officer, came up with a clever premium candy packaging strategy pioneered by the chewing gum industry. The paper boxes open like an envelope with a curved flap shaped like a ribbon of poured chocolate. The tray slides out. Once you pick out a Thin – or three – you slide the tray back in and close the envelope.

The packaging “hits the gift-for-me, self-gifting treat that women, especially, are looking for,” said Joan Steuer, founding editor of Chocolatier Magazine and president of her own Beverly Hills, Calif., consulting firm, Chocolate Marketing LLC.

Steuer spent a year tasting Brown & Haley’s laboratory attempts to get the right blends.

“It’s really difficult to get the butter notes and the sweetness of dark chocolate to melt together in your mouth. It’s a big challenge,” she said.

Unable to find a dark chocolate that worked, Brown & Haley had to order a new, signature blend of 60 percent cacao.

“Then one day, Pierson says to me, ‘Joanie. This is tasting, not eating.’ And I said, ‘Well, Pierson, I guess that means you got it right.’”

For us novice consumers, Roca Thins make a darn tasty treat.

But if you’d like a little insight into the industry nuances, Steuer says Roca Thins hit a rare niche straddling the popular candy and occasional confection treat markets.

“It puts Roca right in the middle of where the market is going,” she said. “I am a fan.”

Me too.

Dan Voelpel: 253-597-8785

dan.voelpel@thenewstribune.com">dan.voelpel@thenewstribune.com