The shelf life that I have seen is generally around 4 months. If stored in a cool area, it should keep a bit longer, but might not be quite so good as when used before the 'best buy' date.
Until the expiary date.
Chardonnay is good for about 7 years unopened.
It may be depending on age
Nothing can stay good if it never was.
for about a week
Read the label. It will tell you how long it will last. However, you can keep an unopened jar of jam for years and it will still be good.
Sadly, not long, especially if it's Amontillado, they're only good for like a month. Medium Dry sherries should be good for about a year.
No. Commercially prepared mayonnaise is shelf stable and can last for several month in an unopened container in your cabinet. Fresh onions can't do that.
Potentially centuries if it is good quality originally.
An unopened bottle of Pennsylvania Dutch egg nog will be good for up to seven months. This variety of egg nog contains alcohol.
Yes, hard liquor lasts for a really long time unopened.
It was last for decades if unopened.
Soup is perishable. However, if it is canned and unopened, it will be good for a very long time.