The first time Michael Mast made chocolate bars from scratch with his older brother in the kitchen of their shared New York apartment, he knew there was no turning back.

“That first batch we made—it was like tasting chocolate for the first time,” he recalls.

Shortly thereafter, the Iowa City native and 2001 University of Iowa economics graduate set aside a career producing independent films and joined forces with his culinary-minded brother, Rick, to form Mast Brothers Chocolate.

What started as a kitchen enterprise in 2007 has turned into a store-front chocolate factory in Brooklyn that employs 35 people, produces 5,000 to 10,000 bars of chocolate a week, and services some 500 accounts across the country, including such restaurants as New York’s Per Se and such retailers as John’s Grocery in Iowa City. A retail space connected to the factory sells the bars as well as fresh pastries, cookies, cakes, fudge, truffles, and bonbons. To keep up with demand, the company is building a second factory.

The bold decision to venture into the world of craft chocolate stems back to a dinner party, explains Mast.

“My brother and I were always curious about the process of making things, whether it was beer or bread—or pickling just about anything,” he says. “We used to host dinner parties, and one evening the conversation turned to chocolate. Although chocolate is arguably one of the most popular foods, very few of us knew how it was made, and that sparked something.

“We started doing research and, as it turns out, very few companies were actually making chocolate from scratch. What excited us was the prospect of sourcing the beans and making it ourselves, and then using that experience to introduce people to and educate them about the process—to connect our customers to the source. Most people who come in our door have never seen a cocoa bean. They think of chocolate as a bar you buy in a gas station, but it is made from fermented fruit. We should treat it as a food, not as candy.”

Mast and his brother committed themselves to making chocolate from bean to bar—that is, they purchased cocoa beans from a small farm in the Dominican Republic and used ordinary household appliances to make chocolate bars. They roasted the beans in their oven (“It made the whole apartment smell like brownies. We knew that was a good sign,” he says), hand cracked the beans to remove the shell, and blew away the husks using a hairdryer. What was left were the cocoa nibs, considered the “meat” of the beans, which were then ground by a stone–on-stone grinder customized by a friend to replicate the grinding process used by the Mayans. After adding sugar, they let the mixture rest before pouring it into molds. The first batch produced 12 bars.

“We started making chocolate for the local farmers markets,” says Mast, “and now our chocolate is available across the world and is used by the most discerning chefs in the finest restaurants.”

Although the operation has grown, many things remain the same—a selective list of ingredients, for example: “Our chocolate recipe is certainly unique,” Mast says. “When you source the best ingredients you don’t need to hide them behind soy lecithin, fake vanilla, extra butters and oils, or too much sugar. We believe in clarity of flavor, a unique simplicity that makes our chocolate so beautifully complex.”

Maintaining purity allows the chocolate makers to highlight the individual characteristics of the beans, Mast says, noting that beans grown in the Dominican Republic have hints of tobacco and taste more earthy, while Madagascar’s beans are brighter and more citrusy. “We want to take people on a journey,” he says.

In fact, Mast has traveled extensively to source the beans himself, and even chartered a 70-foot sailboat in 2011 to the Dominican Republic to pick up and deliver 20 metric tons of beans packaged in burlap bags. (It was the first commercial import by schooner to the Port of New York since 1939, and plans are under way for another such trip in 2014.)

In addition to showcasing beans of a particular origin (beans from Belize, Ecuador, Venezuela, and Papua New Guinea are also used), the company produces chocolate bars for artisan and reserve collections. The artisan collection pairs Mast Brothers Chocolate with complementary ingredients from small, like-minded businesses and co-ops—for example, Anderson Almonds in California, sea salt from the coast of Maine, and Stumptown Coffee in Portland, Ore. Limited-edition batches—special, often decadent, combinations like black truffle or crown maple—make up the reserve collection.

Mast spends most days at the factory, and the entire staff gathers around a large table every morning at 11 to discuss ideas and upcoming events and, of course, to participate in tastings. The company’s primary goal, he says, is to make the most delicious chocolate.

“We like to say, ‘Like our chocolate now? Wait until you taste it in 20 years.’ We are constantly evolving and improving,” he says. “We still feel like we’re making chocolate in our apartment. We still hand sort every bean. It’s just that the apartment got bigger, and we have more friends working with us.”

Although Mast hasn’t quite left the film industry—he and his brother are producing a documentary about Captain Eric, the man with whom he sailed to the Dominican Republic for cocoa beans—he says the chocolate business is extremely satisfying.

“I enjoy tasting everything, and I’ve really enjoyed learning about it—chocolate has such a rich history—and visiting different farms and connecting those farms to our customers,” he says. “Working as a family business, with my brother and our entire team, is very rewarding. And in the chocolate business, no matter what you do, people are always talking with a smile on their face.”

For additional information on Mast Brothers Chocolate, visit the Mast Brothers Chocolate website.