This summer’s heat wave was good news for iced beverages - and not just of the coffee variety.

Itsu, the oriental restaurant and retail brand created by Pret A Manger founder Julian Metcalfe, claims sales of its iced tea doubled in July alone.

“The good weather made a significant impact on sales,” says Robert Jakobi, MD at Itsu’s owner Metcalfe Food Company. “Our iced tea is stocked in Itsu and Waitrose, but we’ve had interest from other retailers and caterers. We’ll be expanding soon.”

Itsu entered the tea market in February with iced white tea in pomegranate and peach flavours, in innovative cardboard ‘cans’. “We saw a growing market for ‘cold hot drinks’ as well as a growing demand for healthier drinks,” says Jakobi. “Our iced teas are unique - they’re made with white tea extract, which is full of antioxidants, reduces cholesterol and decreases blood pressure.”

Itsu isn’t alone in having spotted potential for iced tea here in the UK. In February, US brand Arizona Green Tea, a favourite of celebs like J-Lo and Gwyneth Paltrow, rolled into Ocado and last month, Vivid Matcha (above), made from traditional Japanese powdered tea leaf, was launched in Whole Foods Market, Planet Organic and As Nature Intended. Founder James Shillock said at the time that matcha would benefit from its healthy credentials. He’s now seeking listings in the multiples.

Iced coffee brands also continue to court mainstream retailers. Emmi, which kickstarted the market back in 2007 with the launch of its Latte range, unveiled three-packs last July. Jimmy’s Iced coffee won listings with 260 BP Connect and BP M&S stores in July and its original, skinny and latte variants hit Tesco this month. “Our growth has been exponential,” says founder Jimmy Cregan, “The category has unreal potential.”

Morrisons seems to agree. In July, it became the first multiple to launch an own-label iced coffee.