Found a box of home brewed beer in an old cellar marked 2005. Bottles look ok and caps are good. Would it be safe to drink?
Try one and pour it in a glass gently to see if there is year sediment. If there is some, that means that the beer was bottle conditioned (good sign) but still try to keep the sediment out of the glass as much as possible.
There are some wheat beers that get better with age if this is a Belgian or select German style!