I received an old bottle of Carolus Doppelbock over the weekend from my Grandmother as she recently passed away. They brought it back from a trip they took to Eurpoe in the early 90's. I wanted to ask a couple of things: 1) How can I tell how old this bottle is? It has no dating noticeable on it, but I know that I've seen it on the shelf in their basement bar for at least 20-25 years. 2) Has anyone here ever aged a beer of this style for this long? It was not stored in a "cellar" just sat on a shelf behind their bar at room temp for a long time. Should I open it and drink it, or just continue to keep it as a reminder of my grandparents? Thanks for any insight you might be able to give.