title_body: Vintage port stored on the side
upvoted_answer: It is generally preferred to store wine on it's side, but I think the climate the wine is stored is even more important. Generally, a wine like a vintage port, will spend only a short part of it's lifetime on a shelf in a store. I really doubt that even a year or two will dry out the cork unless the humidity levels are very low. One way to check if the ullage level is low. Ideally, any wine that you want to age should be kept on it's side, in a dark, cool location. Moving the wine upright and back once a years is not ideal. Will it hurt the Port? I really doubt it. Port is pretty sturdy stuff since it's fortified. I wouldn't worry too much about it. The age is also a factor. If it's 10 years old, that's nothing for a port. If it's 50 years old, then I start to worry about it...