Easter Road independent wine and beer specialist Cornelius has had its licence suspended for two weeks by city licensing leaders after twice failing a "test purchasing" blitz by police.
James Wrobel, owner of the business, which has one of the widest selections of beers in Scotland, served the first test purchaser himself on 26 September and was given a warning that a further test purchase would take place within a fortnight.
However, when test purchasers visited again two weeks later, another member of staff – who has since left the business – failed to ask for ID.
The store had to shut down on Tuesday and will not reopen until 9 February..
Mr Wrobel, 35, today admitted he was "embarrassed" by the error and accepts the suspension handed to the store, which has been open for five years.
"Hands up, I'm guilty as sin and I just feel so angry with myself and embarrassed," he said. "I have been doing this for 15 years and I am pretty sure it is the first underager I have sold to and it was a test purchaser. It's sod's law.
"But we messed up. The licensing board have been fair and we hold our hands up."
Licensing board members admitted it was "disappointing" to have to suspend the licence of a shop that is "an asset" to Easter Road.
And Mr Wrobel, who lives in Leith, said: "I was out of practice at looking for kids buying (alcohol] because I don't see them often. We don't have a problem with underagers.
"There are kids that sometimes hang about outside, but none of them would come in to buy anything because they would assume they wouldn't get served."
Mr Wrobel said a longer suspension could have threatened the future of the business, but said the decision to close it for two weeks means it will be able to reopen.
He informed customers of the news on the store's Twitter page, where he wrote: "We will be closed from tomorrow (26th Jan) until Tuesday 9th February. Repeated managerial lapses have resulted in a suspended licence (D'oh)."
At a meeting of the city's licensing board, some councillors had called for the shop to get a longer four-week suspension of its licence, but a vote went in favour of licensing leader Marjorie Thomas's motion for a two-week suspension.
Councillor Thomas said: "It has been an asset to Easter Road to have, dare I say it, an upmarket place like this. So it is extremely disappointing to have a premises like this suffer these problems."
She added: "From a board's point of view, this is the sort of case we didn't want to see because we have to take a strong line."
Police said that Cornelius was targeted as part of the Operation Arraign test purchasing scheme, which attempts to crack down on the unlawful supply of alcohol to underage customers.