BrewDog, the craft brewer that prides itself on the “punk” ethos behind its beers, is plotting a move into coffee in an attempt to lure more customers to its bars during the day.

The Scottish company’s annual accounts show that it has bought a 33% stake in Edinburgh-based Third Wave Coffee.

Third Wave houses a coffee shop called Brew Lab that espouses similar principles to BrewDog by presenting a craft alternative to multinational corporations.

The name is understood to be a reference to the so-called second wave of coffee culture that saw chains such as Starbucks and Costa come to dominate the high street coffee industry.

BrewDog wants to offer Third Wave’s coffee in its 29 UK bars. The move echoes efforts by pub chain JD Wetherspoon to boost revenues and get more people through the door by serving breakfasts from 7am.

While BrewDog customers can already order coffee produced by a third party, the decision to buy a stake in Third Wave marks an evolution in its efforts to attract caffeine lovers.

Figures released by BrewDog show that pre-tax profit fell from £3.65m to £3.5m last year. Profits stagnated despite a 51% increase in revenue, from £30m to £44.7m, with UK sales up by 131%.

This was largely down to heavy investment to increase the company’s brewing capacity amid a surge of interest in independent brewers.

The company’s spending included £20m at its Ellon brewery on the east coast of Scotland, designed to increase capacity fivefold to 1m hectolitres a year.

BrewDog is investing £17.6m to build a brewery in Columbus, Ohio, as it looks to break into the highly competitive US craft beer market.

And the company opened 16 new bars in 2015, capitalising on its status as the fastest-growing UK food and drinks company over the past four years.

It also succeeded with a fourth round of its equity for punks crowdfunding initiative, which has seen BrewDog raise £14m, a world record for equity crowdfunding.

BrewDog’s publicity strategy has included high-profile stunts designed to show off its zany, independent credentials, including throwing taxidermy “fat cats” out of a helicopter over London.

The company’s annual report was characterised by the same irreverent humour. “We kidnapped the president of [multinational drinks company] AB InBev and forced him to drink beer,” the report said, among a list of achievements for 2015, before adding: “This did not actually happen. Although it is a good idea.”