YOUNG AT HEART: Sunny Narran, 47, was refused service in Christchurch last week when he tried to buy beer because he was mistaken for a teenager.

Sunny Narran has been drinking heavily from the fountain of youth.

The 47-year-old was refused service when he tried to buy beer in a Christchurch supermarket because he was mistaken for being too young.

Narran, a contractor with four grown sons, popped in to the Wainoni Rd Pak'n Save at 3pm on Sunday to buy beer and bread.

He said that when he got to the checkout, the supervisor said he would not be taking home the beer because he was under 25.

Narran, who is "going bald" and sports a "heavy moustache", was not carrying identification to prove his age.

"I said, ‘You must be kidding'," he said.

"I'm 47. I will be 48 next month."

While being mistaken for a teenager was amusing, the way the supervisor acted left him feeling "ashamed" and "embarrassed".

"She said, ‘I'm not serving you, you're [under 25]', and then she just walked off," he said.

"I was stunned.

"There were customers behind me staring at me and I was so ashamed."

Narran said it would have been better if the checkout supervisor had taken him aside and explained the situation, instead of refusing to serve him.

He complained and eventually the supervisor relented and sold him the beer.

Foodstuffs communications director Antoinette Shallue said store staff "were mistaken in thinking that the customer was under 25 and have since apologised to the customer involved".

"While mistakes can occur on rare occasions, such instances are dealt with on a case-by-case basis," she said.

"Staff at the store have been reminded of the relevant liquor legislation and Foodstuffs policies, and will be working hard to adhere to all requirements."

All Foodstuffs stores operate an "Under 25: ID required" policy that requires anyone who looks under the age of 25 to provide proof of their age.