Employees of Stone Creek Coffee will start voting this week on whether to form a labor union.

Ballots are being mailed to eligible workers by the National Labor Relations Board Monday, and must be returned by April 1, said Maria Brondino, a Stone Creek barista who is recording secretary for the organizing committee. Ballots will be counted April 2

If approved by workers, the Stone Creek union — part of Teamsters Local 344 — would represent up to 140 baristas, roasters, production workers, delivery drivers, bakers and others who work for the Milwaukee-based coffee company, Bill Carroll, secretary-treasurer of the local, said Monday.

Stone Creek has about 200 employees in all.