A strong performance from Johnnie Walker whisky and a return to growth for Smirnoff vodka helped drinks giant Diageo grow sales by 7% over the past six months.

Volumes were up by 3% in the period to 31 December, the Guinness brewer said, with the rest of the additional revenues coming from price hikes.

While volumes were flat in Europe and North America, sales in emerging markets surged by 18%, to now account for almost 40% of Diageo’s business.

“Diageo has delivered a solid and well balanced first half performance,” said chief executive Paul Walsh.

“This is the result of the investments we have made to build our brands, deepen our routes to market in the faster growing markets of the world, enhance our leadership in US spirits and create an integrated organisation in Western Europe.”

He added: “In an uncertain economic environment we have again demonstrated the benefits of our geographic diversity and brand range.

“We are cautious as to the consumer and economic trends we will face in 2012 but these first half results have positioned us well and they have demonstrated that Diageo has the brands, the routes to market and the people to deliver our medium term guidance.”

Meanwhile, Guinness has paired up with London chocolatier William Curley to produce some limited edition truffles made using ‘the black stuff’. The chocolates are available in time for Valentine’s Day via Curley’s stores in Belgravia and Richmond, as well as online.

Watch Curley’s video here.