Portlaoise had the second highest level in the country.
Nearly 400 litres of homemade alcohol was seized in Irish prisons last year.
According to freedom of information figures, nearly half of the total was found in Mountjoy jail.
A total of 391.5 litres of hooch was seized in eight jails across the country last year.
John Cuffe is a criminologist and former prison officer - he says it's been popular among inmates for many years.
49 per cent of last year's total was seized in Mountjoy Prison - involving 192 litres of hooch.
That's followed by 82 litres in Portlaoise, 41 in Wheatfield Prison in Dublin and 35 in Cork jail.
The total figure is almost exactly the same as 2019, when 395.5 litres of hooch was seized.