Can port wine go bad

Answer 1

Yes, anything with wine in it will go bad in time. It will turn sour and taste like vinegar. Cooking wine is just wine with salt and other seasonings. I wouldn't use it at all. Just use real wine and salt the food to your taste.

Answer 2

Cooking sherry or any cooking wine for that matter is already bad by design when you buy it: Only the worst wines that can't be legally sold as sherry or drinking wine are used to make cooking wine as a way to still make big bucks on these defective products that would be used for vinegar otherwise.

Cooking wines have salt and a bunch of other flavorings or chemicals and whatnot added, but that does not prevent them from spoiling. It probably has to do more with the fact that cooking sherry is the least fruity sherry, and is therefore less likely to keep for long, although this can be prevented by adding more sugar if it is sherry.

It does not turn "bad" though, it just turns into vinegar and after it is fully turned into vinegar in a few months, it can be used in French dressing, to deglaze fried onions or gravy, to marinate meat, etc.

It will still be a low quality vinegar, because garbage in, garbage out and that sort of things, but not a total waste.

Sherry vinegar is a much sought after product. Quality sherry vinegars sell between $15 and $30 a bottle, depending on their age and origin (search for Banyuls vinegar for instance.)

Answer 3

Port is a fortified wine and, as such, should not "go bad" even if kept for decades unopened.

Answer 4

Yes, wine can go off, and turn to vinegar. The best way to preserve wine is to keep the bottle sealed when you are not drinking it. Exposure to oxygen will eventually cause it to go off.

Answer 5

No the vinegar will preserve itself. It will loose flavor over time.