Drinkers kept out of their locals by lockdown drove a 70% jump in shop sales of lager and beer to £29.5m, the Belfast Telegraph can reveal.
Compared to 2019, drinkers spent an extra £18.5m on beer and lager, wine, and cider over the three months to December 1, a grocery market report by Kantar said.
The total spend hit £77.5m - up from £59m.
Beer and lager sales had the strongest percentage increase of the three types of booze tracked by the information company.
Figures shared with this newspaper show wine sales grew by nearly a fifth to £43.3m in the 12 weeks.
But cider fell out of favour for those drinking at home, with sales down nearly 8% to £4.7m.
The period included six weeks of lockdown for restaurants and bars serving food, aimed at containing the spread of Covid-19.
Bars serving drink only were open for just three weeks within the period. At the moment, bars can only open where they serve food from a kitchen on the premises.
Kantar monitors sales in supermarkets like Tesco, Asda, Sainsbury's and Lidl, as well as convenience stores like Spar, Centra and Mace, and off-licences.
But it does not track sales of spirits.
Retail analyst Emer Healy from Kantar said that as well as buying alcohol to compensate for closures, customers may have been stocking up for Christmas.
Colin Neill, chief executive of pub trade body Hospitality Ulster, said it was no surprise the closure of bars was driving up sales of alcohol.
But he said it also meant an increase in social mixing and a less controlled environment for drinking, where the risk of Covid-19 transmission was potentially greater.
"While we're closed, we're not only driving up alcohol sales but house parties too," he said.
"That's going to increase over Christmas, but hospitality will end up paying the price by being locked down. Our traditional pubs have only been opened for three weeks since St Patrick's Day... I appreciate while we're closed, people will obviously want a beer or a gin and turn to the off-sales market for that.
"It's not us complaining about customers and their behaviour, but it's depressing in that our pubs have spent so much and put measures in place and have not been allowed to be open."
He said some pubs permitted to open under the current lockdown were weighing up whether to stay open and lose money, or stay closed and lose money.
"We need to have adequte compensation from the government where (bars are) not in a position to be open," he said.