The owner of a Belfast-based brewery has come up with a plan to help the victims of Monday’s Boston Marathon bombing.

David Carlson, owner of Marshall Wharf Brewing Co. in Belfast, developed the idea for Buy Boston a Beer and pitched it successfully to other brewery and tavern owners.

About 20 breweries from across Maine and New England have agreed to donate beer to a fundraiser that will be held Wednesday at The Tavern Framingham in downtown Framingham, Mass.

“David got the ball rolling and we offered the spot. It snowballed from there,” said Sam Hendler, the owner of Jack’s Abby Brewing in Framingham, Mass.

Hendler, who is organizing the fundraiser, said Oxbow Brewing in Newcastle, Shipyard Brewing in Portland, Allagash Brewing in Portland, Maine Beer Co. in Freeport, Atlantic Brewing in Bar Harbor and Marshall Wharf Brewing are the Maine companies that have agreed to donate beer.

Hendler said all the proceeds from the event, which starts at 3 p.m, will go toward the One Fund Boston, a fund established by Massachusetts Governor Deval Patrick and Boston Mayor Thomas Menino to help the victims and their families.

More than 20 kegs of beer have been donated, or about 1,000 pints, according to Hendler.

Carlson could not be reached Tuesday.