The original 25% ABV coffee liqueur was developed in Australia by business partners Phillip Moore and Tom Baker in response to a lack of a "real coffee liqueur on the market", said Baker.
Earlier this year, Mr Black picked up the award for Favourite New Exhibitor by trade and consumers at the London Coffee Festival, despite entering the UK market just before the April event.
Widely available
However, the brand is now widely available from all major foodservice distributors and is becoming visible in pubs and bars across the UK, according to Baker.
"Pubs understand that that their clientele want to drink good coffee and for an after-dinner drink, a coffee liqueur can [potentially] make them more money because they can charge upwards of £4 for it at the end of meals – and will people have just one?” he told the Publican's Morning Advertiser.
The liquid also lends itself to cocktail-making, he continued. Alternatives on the market contain no caffeine, according to Baker, while Mr Black contains a high amount of caffeine.
Drinks he suggested operators tried were twists on classics, such as a coffee Negroni, the Old Fashioned or even to use it in an Espresso Martini, which have become very popular in the UK.
Small company
Yet, the small company, which produced around 40,000 bottles of Mr Black for its home market last year, had experimented with its brew by ageing it in whisky barrels.
Baker said: "We started with 100-litre whisky casks from the Australian whisky makers. We've now secured some 200-litre casks from the Del Winnie distillery in Scotland, which is the coldest distillery in the world so is quite fitting for us.
"The barrel-aged Mr Black is the ultimate digestive and has a taste of whisky."
It will launch in the UK later this year.