Ireland's oldest stout brewery, Beamish and Crawford, will fully shut down by the end of May.
New owner Heineken confirmed that it had been due to shut the Cork plant today but logistics have delayed the closure.
80 of the 160 workforce have already been made redundant.
40 other workers have transferred to Heineken's Cork headquarters, while the remaining 40 workers will oversee the fermentation and bottling of the final beer product at the South Main Street plant.
Heineken has also confirmed that it is their intention to sell the four-acre site in the old city of Cork, once decommissioning of the plant is complete, which could take up to 18 months.
Corporate Affairs Manager Declan Farmer said Heineken is not in the business of developing property and while the company is aware of both the historic and heritage value of the site, once a sale is agreed, his company's involvement in the site will cease.
Historians say there has been a brewery on the site from the mid-1600s.
Heritage campaigners are concerned about the future of the site and its famous Tudor counting house.
The National Conservation and Heritage Group, which persuaded Guinness to develop the Guinness Storehouse in Dublin, has said it will take its campaign to save the site to the streets, if the multi-national brewer does not ‘engage with them in a meaningful way’.
It wants the company to develop a micro-brewery style tourist attraction at the historic site.
Heineken has confirmed that Beamish will no longer be sold anywhere outside Ireland.
The company says it is to focus on selling it in the Irish market.
