You're right: they don't offer brewery tours. The tasting room is pretty nice though. I'm afraid that I've never had Dinner either. We've never managed to get over there for a release before it's sold out.
The next time you come up, you could really make a day out of getting some great beer. There's several fantastic craft breweries in Portland: Bissel Brothers, Foundation, Alagash, Bunker, and Rising Tide, to name a few. You could also visit Novare Res, an awesome beer bar in the Old Port. Or if you're back out near Bridgton again, you could visit Ebenezeer's in Lovell, which has been voted the best beer bar in the country and the world a few times over.
Just typing all of this out is making me thirsty!