NEW YORK • The integrity of a cherished Brooklyn-based brand of craft chocolate bar has been called into question, after a food blogger published a four-part series of blog posts this month, accusing the two brothers who founded it of faking everything from how they learnt to grind their cacao beans to the ingredients in their candy and even their beards.

The accusations published on Dallasfood.org elevated what had been a long-whispered rumour in the fine chocolate world about Rick and Michael Mast, the two brothers with trendy lumberjack beards and a charming origin story behind Mast Brothers Chocolate in Williamsburg, and it quickly spread to those whom cacao bean varietals and cocoa percentages mean little.

The allegations have drawn comparisons with Ponzi schemers and on social media to Martin Shrekli, the former pharmaceutical company executive who steeply raised prices on some drugs and has been charged with securities fraud. It has thrown into question not just the provenance of a chocolate bar, but also the predilection for such goods, with perhaps larger implications for the picked-by-hand, farm-to-apartment movement, underscoring the fact that claims of homespun authenticity are not regulated, or often verified.

"The Masts did not become pariahs in the fine chocolate world because of their beards, publicity or product mediocrity," the blogger, Scott Craig, wrote in the series, What Lies Beyond The Beards. "It was because of their lies."

In thousands of words, which compared the Masts with Milli Vanilli, the 1990s R&B group caught lip-syncing, he voiced scepticism about their skill and their beards, and offered a theory: that early in their career - before their three shops, celebrated chocolate wrapper designer and finding favour with the French Laundry chef Thomas Keller - when making chocolate in their own apartment, it could not possibly have been from scratch.

In an interview on Sunday, Rick Mast, who with his brother began making chocolate in a Brooklyn apartment in 2006, said the allegations were untrue - for the most part. But on the claim that the Masts were "remelters" at the start, he confirmed the brothers did use industrial chocolate, what is known as couverture, in some of their early creations, before settling on the bean-to-bar process for which they are now known.

"It was such a fun experimental year," he said, adding that the brothers were transparent "to anyone that asked".

What has taken the controversy beyond the chocolate cognoscenti seems to be the Masts' Brooklyn- tinged narrative of do-it-yourself chocolate bootstrapping. It is mentioned in their articles and recited by guides during the US$10-a-person (S$14) tours of their Williamsburg shop, where tattooed and mustachioed young men pour silver scoops of beans into grinders. Old pictures of the brothers, then clean-shaven, have been circulating as if to prove inauthenticity.

Over the weekend, Twitter seethed with hipster schadenfreude. "The exposes of the Mast Brothers only make me more self-satisfied about hating their chocolate," a writer named Michelle Dean posted. "The story is a hipster ouroboros."

Rick Mast said the backlash had come as a surprise. "To be boiled down to how you dress or wear your beard, or where you live - I think it's a distraction," he said. "Our chocolate is our No. 1 focus."

On a tour of the main factory in the Brooklyn Navy Yard alongside his brother on Sunday, the Masts stressed their transparency. The smoked glass windows were not to keep people from seeing in, they said, but to prevent sunlight from ruining chocolate.

In response to charges by Craig that the output in their early days was thousands of bars a week - far more than an apartment-based operation could have churned out - they e-mailed The Times a copy of the nascent company's 2008 tax return and said they made no profit that year.

At the Navy Yard factory on Sunday, winnowers growled as beans shuffled through them, crackling as cacao husks sloughed off. Rick Mast stood amid his scuttling employees.

"This," he said over the noise, "is not a show."

NEW YORK TIMES