A South African whisky, which its producer claims is the only one to be double-matured in first-fill bourbon casks and made from 100% South African maize, is now available in the UK.

Bain’s Cape Mountain Whisky, which was first released in South Africa in 2009 and the USA in 2015, is aged for three years in medium-charred bourbon oak casks, used initially to mature bourbon.

The whisky is then revattted into a fresh set of casks for an additional 18 to 36 months of maturation, with this double maturation process ensuring “maximum extraction of flavours” resulting in a finish of spice and toffee, according to the producer.

The warmer South African climate also affects the whisky, accelerating its maturation process and the rate of flavour extraction from the oak.

“As a result Bain’s is exceptionally smooth, a characteristic of generally much older whiskies from a cooler climate,” the producer explained.

Andy Watts, master distiller, said: “Brandy was historically the drink in South Africa but in the 1980s whisky started to get a lot more popular. I looked at the styles of whisky that people were drinking in South Africa and they were either Irish brands or Jack Daniels.

“I could understand what the South Africans liked about bourbon, it had beautiful vanilla sweetness but in my mind it was a bit harsh, so I wanted to look for the smoothness of Irish whisky and the sweetness of bourbon, and I knew the only way I could change the flavour was with the grain and the style of wood.

“I wanted to make a single grain whisky and after some tests I chose maize, and so the only thing left to play with was the wood.”

The whisky pays tribute to Andrew Geddes Bain, who conquered the Cape Mountains and built the Beyerskloof Pass, which connected Wellington in the Western Cape to the interior of South Africa in 1853.

The parent company for Bain’s is Distell, which also has brands such as Amarula, Savanna and Hunter’s Dry. In 2013 it bought Scotch whisky producer, Burn Stewart Distillers.

This is the first whisky the South African company has launched globally.