Squares of pure, dark chocolate sat on plates lining Shambaugh Auditorium, with members of the public daintily sampling the slightly bitter yet sweet hunks of handcrafted dessert, courtesy of the Mast brothers.

Rick and Michael Mast, born and raised in Iowa City, moved to Brooklyn, N.Y., roughly 12 years ago. They spent much of their time in their apartment, brewing beer, curing meat, and making chocolate from scratch.

Their first batch of chocolates was “fresher, more complex, and more interesting than any other chocolate bar” they had tasted.

“It honestly was like tasting chocolate for the first time, just using beans and sugar,” Michael Mast said.

In 2007, the two quit their day jobs, took out a few credit cards, and “made a run for it.” Their goal was to produce the purest chocolate possible by starting from scratch.

“Our criteria are whatever makes the best chocolate, whatever tastes the best,” Rick Mast said. “And we’ve really staked our reputation on being that company that doesn’t compromise.”

Today, the two run a storefront factory, producing chocolate that is distributed throughout the world with nearly 1,000 retailers in roughly 10 countries. The chocolate sells in the United States for $8 a bar.

Their goal is to educate customers about the source of their chocolate.

“All around America, people want to know the first name of the cow they’re about to eat, what its diet was, and where it came from,” Michael Mast said. “They don’t have that same connection to chocolate; it’s just kind of a cheap candy bar at a gas station to get some extra energy.”

The brothers said most of their product is distributed to neighborhood specialty markets that are passionate about quality-driven food with a story. One of those markets is John’s Groceries, 401 E. Market St.

John’s wine expert Wally Plahutnik said there was nothing like Mast Brothers Chocolate.

“It’s like the difference between drinking Guinness and Miller Lite,” he said.

The two recently wrote a book, Mast Brothers Chocolate: A Family Cookbook, which won the International Association of Culinary Professionals award for best cookbook.

The book includes recipes but also adds narration to tell a story the brothers hope will connect readers to the people making their chocolate.

“We are the ambassadors of new chocolate, and we wanted a book that really reintroduced chocolate to the world in a way that takes classic American desserts, and some savory items, and reintroduces them using quality chocolate as opposed to just whatever you have in your cabinet,” Michael Mast said.

The brothers don’t stop here. They have two more businesses set to open this year. One of them is a chocolate house, serving chocolate beverages, that would be located down the street from their current Brooklyn factory.

They also plan on opening a chocolate factory, chocolate house, and retail shop in London.

The brothers said their desire to start a family business came before the idea of starting a chocolate business, and it just seemed to be the “perfect pairing.”

“We have a saying that still holds true: There’s nobody that you will fight harder with than your family, but there’s nobody you would fight harder for than your family,” Rick Mast said.