An 87-year-old man was asked to prove he was over 21 when he tried to buy a bottle of sherry in a York supermarket.
The former Lord Mayor of York, Jack Archer, said he was shocked - but flattered - when asked the question by staff at Morrisons in Acomb.
He said: "I don't look my age but I certainly don't look young enough to be in trouble for underage drinking."
Morrisons said staff were required to ask anyone buying alcohol to confirm they were over 21.
Mr Archer said he often had a small glass of sherry at bedtime to help him sleep.