The shedding of 39 jobs at Launceston's Boag's Brewery has come as a shock, the United Voice union says.

Parent company Lion said it was making the changes to improve efficiency in its brewing network.

The Boag's brands will still be fully brewed in Launceston but various national brands will move interstate.

It will reduce the workforce from 104 to 65, and cut the annual brewing volume from 56 million litres per year to 36 million.

Company spokeswoman Leela Gantman said the market had faced a "challenging" time and added brewing costs in Tasmania had also been a factor.

"We've done this off the back of some very challenging years in the beer market and the need to ensure our operations both nationally and in Tasmania are sustainable," she said.

"Certainly the rate of decline of beer production has been sharper than originally anticipated, so this has put our entire brewery network under pressure."

Contractor roles will also be impacted in the transition which is expected to be completed by September.

United Voice secretary Jannette Armstrong said the decision came as a surprise and was "devastating".

"This is going to have a massive impact, particularly [in] Launceston which is already feeling the hurt of unemployment," she said.

"It is very difficult to find a job at the moment, especially in the Launceston area, so it will be a very, very distressing time for those workers and for their families.

"Last year they laid off a whole heap of casuals and they have been talking about the reduced beer market across Australia, but in terms of any indication they were going to be cutting more jobs [that] was an absolute shock and we're disappointed there wasn't more notice and greater consultation."

Union to press for few job cuts

The union will meet the company on Tuesday and hopes to convince it to reduce the number of job losses.

"It is just such a shock talking about expanding and creating [the brewery's] visitor centre to then laying off all of the casuals and, now this year, laying off 30 or 40 employees, it hurts," Ms Armstrong said.

Some of the 39 workers have been told they will be redundant but others are yet to learn their fate.

The Tasmanian Government said the decision was disappointing.

In a statement, Minister for State Growth Matthew Groom said the company had not requested any assistance but workers were able access support through the department's skills unit.

Ms Armstrong urged the State Government to do more to protect the jobs.

"We would love to see the State Government stepping in to see what they can do to try to keep these jobs," she said.

Labor's Michelle O'Byrne believes the Government could have done more.

"What did the Government do for the last 12 months to ensure that this wouldn't happen, what actions were taken to engage with this organisation so we could deal with whatever barriers were in place and keep these jobs in Tasmania?"

Sackings a 'kick in the pants'

It is another blow for the north.

One hundred workers will lose their jobs when Launceston steel factory, Bradken, closes in the middle of the year.

Launceston Mayor Albert van Zetten said the Boag's move was upsetting for many in the community.

"We want to see continued growth because we have got at the moment lots of positive things happening around Launceston and this is something that's a real kick in the pants," he said.

Boag's was established in Launceston in 1881.