C&C announced in January that it would move out of Shepton Mallet and move production of its ciders to its manufacturing site in Clonmel, Tipperary, leaving more than 100 people without a job.
Brothers has taken over the Krones bottling line and the land and buildings that house it, and will offer certain roles to C&C employees.
But union Unite said there is still a need for a buyer for the main site, where the bottling line cost an estimated £6 million.
Regional coordinating officer Steve Preddy said: “While we are pleased that the line has been sold to the makers of Brothers Cider, also based in Shepton Mallet, this is still an urgent need for a buyer for the main site.
“We are pleased that that there will be an unspecified number of new jobs working on the Brothers line - these are totally new jobs with this company. However, it does not resolve the issue that 127 workers at the profitable Shepton Mallet Cider Mill face being made redundant at the end of the summer.
“The £6 million bottling line was meant to be the saviour of the cider mill. The fact that it is being sold sums up the incompetence of the Irish-based owners C&C Group in the mismanagement of its Shepton Mallet operation. Ironically, it still managed to post about £81 million in profits overall.
“We wish Brothers Drinks well in the expansion of its production capability and hope it can employ as many dedicated cider workers as possible in the future."
Billy Mason at C&C Group said, “We are pleased to have found a trade buyer for a part of the Shepton site and especially pleased that this will provide an opportunity for some C&C employees to join the Brothers team. We continue to explore options for the sale of remainder of the cidery.”
The Showering brothers, owners of Brothers Drinks, said “We are very pleased to be acquiring this site and bottling line so close to where our family began their business 173 years ago. We are a growing company and a local business and we look forward to maximising this opportunity.”