A boycott of Emerson's beer is growing since its sale to Lion Nathan.

Within hours of the Japanese-owned brewer announcing yesterday that it had bought Dunedin-based Emerson's, several bars in Wellington were warning they would no longer stock Emerson's.

Now the boycott has spread to Nelson, with popular independent pub The Free House also taking a stand.

"We won't be selling Emerson's until Lion and DB start allowing guest taps in their bars," The Free House co-owner Eelco Boswijk said today.

A lot of bar taps were owned by breweries, which meant no other beer could be put through those taps, he said.

"We're taking a stand until their guest tap policy changes," he said.

He was slightly surprised at brewer Richard Emerson selling, but did not have any ill feeling.

Emerson's beers, particularly its Bookbinder and 1812 IPA, have avid fans, he said.

He believed there would be other brewery buyouts as the popularity of quality craft beer grew.

It was a smart move by the bigger breweries, because flavoursome craft beers were seen as top-tier products, while the main brewery products were not.

In Wellington, a spokesman for the Hashigo Zake bar said it was "saddened" by news of the sale and would run down supplies before the deal was sealed.

Lion played down the concerns, saying it expected a range of opinions on the takeover.

"Clearly there's a bit of noise around it at the moment, so hopefully we can prove some of those people wrong," brand manager Danny Phillips said.

"Our intent is to maintain the essence of everything that's great about Emerson's and not homogenise it."

Emerson's would be allowed to retain quality and recipe control.