A co-founder of the Scottish craft beer firm BrewDog has apologised to more than 60 former members of staff after they complained of a “toxic” working environment in an open letter that has fuelled concern among the company’s army of small shareholders. In an Instagram post, Martin Dickie wrote: “I would like to wholeheartedly apologise to every single person who has put their name on that list.” “As the person whose idea it was to set up a brewery in the first place and as a director and shareholder and co-founder I feel that the responsibility sits with me.” He offered to engage with any past or former employees who wanted to discuss the working environment at the Aberdeenshire brewery, which was accused of creating a “culture of fear” in a letter earlier this week. Former staff told the Guardian that Dickie’s words met with a better reception thanthe initial response of James Watt, the company’s other co-founder and the public face of both the company’s rapid growth and its regular controversies. Watt initially considered rallying current staff to write a counter-letter before abandoning the plan and issuing a full apology. In an earlier note on a staff forum, he wrote that the company’s “fast-paced and intense environment is definitely not for everyone”. Punks With Purpose, a group of former employees who posted the original open letter on Twitter, said it was “grotesque” to suggest that staff who voiced concerns were underperforming or could not hack it. Amid the claims and counter-claims, the fallout from the affair spread to some of BrewDog’s 130,000 “equity punks”, a typically loyal group of small shareholders who have helped fund the company’s impressive growth. On a web forum for equity punks, one wrote that “as far as I’m concerned, true colours have finally been revealed”. Another said that the appointment of a chair and independent non-executive directors was “overdue” at BrewDog, which is expected to seek a stock market float soon. “[…] The company needs to behave as if it’s a fully listed company along with all the governance that goes with it,” they wrote. BrewDog’s HR team has also emailed staff stating it was “surprised and sad” that working there had left such a negative impression, adding that the letter “paints a different picture of what it’s like to work at BrewDog today”.