Sim said it was “not youngsters” but “people that are our age” who were “bringing in cans, bottles, the little buzz ball cocktails”.
“But they’re still sitting in the pub, still enjoying the entertainment. It’s really frustrating.”
She estimated the pub lost £480 on one of the worst occasions.
Some people were embarrassed and apologetic when confronted, but others became “quite aggressive and mouthy”, she added.
“I’ve got a young team here, and they’re actually scared to approach people.”
Sim said the pub put on a lot of community events, including comedy nights, business support sessions and live music.
“We can’t do all that stuff if people are taking advantage.
“The reality is, if you bring your own drinks, then we can’t afford to get more stock, we can’t afford to have the entertainments.
“We would have to stop doing these great things for the community,” she said.