I met some people from Portsmouth in Portland. They basically told me there was no real reason to detour into New Hampshire and they came to Maine to get the hell away from the place. So take that for what it's worth.
I toured the hell out of Portland's brewery scene when I was up there two years ago. I visited Lone Pine, Rising Tide, Bissell Brothers, Foundation, Austin Street, Allagash, Maine Beer Co., Banded Horn and Barreled Souls.
Maine Beer is up in Freeport, so you can check out LL Bean while you're there. Lone Pine, Rising Tide and Bissell Brothers are near downtown, and there are several others that I didn't hit or have opened since I visited. I wholeheartedly recommend a visit to the Allagash tasting room, even if you don't like Allagash White. You'll get a free sample tray of four beers, plus an opportunity to check out the facility. Austin Street and Foundation are right across the street from Allagash in an industrial park, so you can get to all three easily. Austin Street is run by several women, and their beer is fantastic.
Banded Horn and Barreled Souls are on the way out of town south if you're headed toward Saco-Biddeford. Barreled Souls is basically a little basement brewery that has some super strong beers. Banded Horn is more of an arcade type setting, so that's pretty fun as well.
When I was up there, I checked out Two Lights State Park just east of Portland, and it has some stunning views of the craggy coastline. Also visited Wolfe Neck Woods State Park when I went up toward Freeport for the stop at Maine Beer Co. There are a couple of easy hiking trails there and great views of the coastal scenery.
