In the answers to the popular question What defines cooking wine? one common recommendation seems to be to simply use regular wine.
However, it seems that wine goes bad in a few days. I don't consume wine, except for cooking wine, which from the answers to the above question seems to be a suboptimal choice.
Hence the follow-up question: How can I increase the shelf life of regular wine? Is it possible that a wine that has gone bad/sour is still useful for cooking while it is unfit for drinking?
The closest answer I could find is linked below. There the recommendation is vermouth. But that perhaps is a preference. I am curious if there's a simple answer to elongate shelf life where a wine can be used for months for cooking. https://cooking.stackexchange.com/a/3034/33912