A Maine brewery is planning an expansion that will quadruple its capacity over time. Baxter Brewing Co. said Monday its brewery in Lewiston will grow from 8,000 barrels to more than 33,000 barrels by the time the expansion is complete. Company founder and president Luke Livingston says demand has exceeded supply since his small, craft-beer brewery began distributing its beers in early 2011. Baxter says he’s also upgrading his canning line and searching for additional off-site warehouse space. Livingston says the expansion will result in an additional 15 to 20 brewery jobs in the next 18 months, as well as construction jobs for the brewery expansion.