Mmmmaking Chocolate

James Bond would have his hands full trying to unlock the secrets of this place. From the outside, it looks like an ordinary old factory. But inside, it seems more like a top-secret headquarters. And the secrets it's protecting are chocolate ones.

At the Merckens chocolate factory in Mansfield, Mass., sweet stuff is serious business. No recipe goes unguarded, and one man holds the key to them all.

His name is O'Korn. Frank O'Korn, and he's director of manufacturing, the mastermind of chocolate operations here. He's got a license to cocoa.

"The chocolate industry is highly competitive," says Mr. O'Korn, dressed unassumingly in a white lab coat. "That's why our recipes and cooking procedures have to be kept secret."

So why have you never seen a Merckens chocolate bar? Well, that's sort of a secret, too.

Though you were unaware of it, you've probably eaten cookies made with Merckens chocolate. Any brand of chocolate-chip cookie sold in supermarkets could contain Merckens chips, O'Korn says.

"I can't tell you which ones," he continues, hesitant lest he reveal something he might regret. "But I can assure you that we make billions of chips a year, and they all have to go somewhere."

O'Korn has to keep his lips sealed because Merckens sells chocolate chips to cookie companies that compete against each other.

Along with the tons of chocolate chips, Merckens also makes giant 10-pound milk- and dark-chocolate bars. Confectioners use the chocolate to coat the fine chocolates sold in fancy boxes.

Trying to stay ahead of the competition

Tucked away in his fourth-floor laboratory, Jerry Huard has a smirk on his face. The product-development technician is pleased: He's cracked some of the chocolate industry's biggest secrets in the nearly 30 years he's worked here. Some he can tell, but others must remain within the walls of the factory. He's free to unlock the simple mysteries of chocolate, but nothing that could give his competition the upper hand.

The quality of new chocolate recipes is tested in Mr. Huard's laboratory. But from time to time he's called upon to whip up a recipe that tastes exactly like a competitor's brand of chocolate. It's his toughest challenge, he says

"If Merckens can make a product that tastes the same but for less money," he says, "we're able to gain a competitive edge."

Huard must know the answer to this chocolate mystery: What's the difference between milk chocolate and dark chocolate?

Milk chocolate is made from blending at least 10 percent baking (unsweetened) chocolate and 12 percent milk with cocoa butter, sugar, and sometimes other flavors, he says.

Dark chocolate, which contains no milk, is made by blending a minimum of 35 percent unsweetened chocolate with sugar and cocoa butter.

Here's a tougher one: Why don't two brands of milk chocolate taste the same, even though the ingredients are identical?

Answer: milk and beans. Where the milk comes from makes a big difference, Huard says: "Milk from California tastes earthy. Milk from New Jersey is really creamy. Each one could make a chocolate bar taste different."

Chocolate comes from cacao (kah-KAH-oh) beans. (Another mystery: Why cocoa and cacao? Cocoa is probably a misspelling of cacao that stuck somewhere along the line.) Different varieties of cacao have distinct tastes.

"Some beans have a smoky flavor," O'Korn says. "Others are acidic. It all has to do with where they're grown and soil conditions."

Merckens imports beans from eight countries throughout Africa, Central America, South America, and the Caribbean. The beans arrive at the factory in huge sacks.

First they are cleaned and put through the micronizer.

This machine heats the beans. The heat makes the moisture in the bean expand. The expansion cracks the beans' thin outer shell. Noise from the machine sounds like popcorn popping in a microwave.

What's left looks like shelled walnuts. These are the "nibs" or the "meat" of the cacao bean.

Next, the nibs are roasted. Since roasting brings out more of the chocolate flavor, the details of the roasting process are kept under wraps.

The roasted nibs go into a grinder. The friction of the huge grinding machines causes the cocoa butter in the nibs to melt. Cocoa butter is a vegetable fat that looks like caramel. But don't put any on your ice cream: It tastes like suntan lotion.

After the the cocoa butter is removed, a thick paste is left. It's called "chocolate liquor," though there's no alcohol in it - just pure cocoa and some cocoa butter. Though it looks like smooth dark chocolate, it tastes very bitter.

The top-secret part of the process

The liquor can be hardened to make unsweetened baking chocolate. Or it can be pressed to remove still more cocoa butter and then pulverized into cocoa powder.

The liquor that will become eating chocolate goes through the most secret, most important process of all: conching. It's called conching because the machines that do the conching used to look like giant conch shells.

The process develops much of the flavor and texture of the chocolate. All the other ingredients (sugar, milk, other flavorings) that go into the chocolate are put into the conch.

"The way chocolate tastes has a lot to do with the time it stays in the conch as well as the temperature in the conchs," O'Korn says. "And no chocolatemaker is going to tell you his formula."

The chocolate may be conched for days. The process also breaks up the sugar crystals in the mixture so the chocolate will be smooth.

"The smaller the particles in the chocolate," O'Korn says, "the better the chocolate."

Finally, the chocolate is tempered. It's heated, cooled, and heated again. This also makes it smooth. Then it's molded into bars or chips.

There may be a lot of secrets to making chocolate, but one thing is no mystery: Nearly everybody loves it, even secret agents.