Richard Farrer was found behind the wheel of his mother's car in Crail, Fife, on October 31 last year while five-and-a-half times the drink-drive limit.
Farrer's lawyer told Cupar Sheriff Court he had "no recollection at all" of driving the car.
When he was pulled over and breathalysed police found he had 192 microgrammes of alcohol in 100 millilitres of breath.
The limit is 35 - meaning Farrer was precisely five-and-a-half times the limit.
The highest reading reported in Scotland was six times the limit.
Farrer had faced jail when he appeared for sentencing but was instead handed a community payback order.
Sheriff Charles Macnair QC said the offence was "inexcusable" and that custody was the "appropriate sentence".
But he said the maximum sentence for drink driving is six months - and as he was a first offender the "appropriate" sentence would be four months.
That would then have to be reduced by one-third because Farrer pled guilty at the earliest opportunity - meaning a maximum sentence of 80 days.
Sheriff Macnair said that because of a presumption against short sentences in recent Scottish Government legislation he had to instead impose community service as an alternative to jail.
The court heard Farrer was found behind the wheel in St Andrews Road, Crail - a busy main road out of the town towards St Andrews, Cupar and Dundee.
Farrer, 43, of Bowbutts, Crail, Fife, pled guilty on summary complaint to a charge of driving while under the influence of alcohol.
Douglas Wiliams, defending, said he was driving the car to help out his 69-year-old mother Mary.
He said: "The car is his mother's - it is used for her convenience for shopping and trips and is driven mainly by the accused as she can no longer drive.
"This was clearly a public safety issue - he has no particular recollection of being in the car or driving.
"He is clearly extremely remorseful.
"He has lost his employment as a result of this offence."
Sheriff Macnair placed Farrer on 18 months supervision and ordered him to carry out 300 hours of unpaid work in the community.
He also banned Farrer from driving for 32 months.
He said: "You got behind the wheel of a car with so much alcohol in your breath that you gave a reading of 192 microgrammes, which is more than five times the legal limit. That is the highest I have ever seen and it is completely inexcusable."
The highest reading previously was set by Robert Campbell in Elgin in March 2002.
Campbell was caught at more than five times the limit twice in the space of a month.
His second offence saw him register a reading of 210 microgrammes of alcohol - precisely six times the limit.
Campbell had been on his way to court for a hearing over the first offence when he was caught for the second.
He was later sentenced to four months in jail and banned from the road for 10 years.