My friend Brian, an intern of mine when I worked in Cincinnati, recently came for a visit. He wanted to check out the Anheuser Busch brewery tour. While I'd been on the tour before, it was worth another trip.
The tour itself is about an hour long. At the end of the tour, you are rewarded with 2 free samples of AB's best! Be aware that you will encounter really hot and really cold environments along the way. We went on a sweltering day and I don't really recommend it. Also, try to pick a day that won't be too crowded. The day we went, the wait to start the tour wasn't terribly long, but the waiting area and gift shop was just completely overrun. The Cards were home and it was clear most of the folks on the tour were in for the game.
The tour details the history of the brand, but also takes you through the whole process of brewing the beer. It's quite interesting.
My favorite part though is seeing the famous Clydesdales. You get to go into their stables and sometimes the dalmations are wandering around too!
With the InBev takeover, there's no telling what, if anything, will happen to the tour. I say go soon just in case. It would be a shame to miss what I consider one of the quintessential St. Louis things to do. If you want more information, here is their website.