How long does red wine keep for, once opened?

[Clawdius]

I opened a bottle of red wine on Wednesday. We're not big drinkers, so have half a bottle left. It has been on the table since, with the screw cap on the bottle. How long is it good for? I was thinking of using it Monday to make a casserole in the slow cooker. Will it be okay to use?

You could freeze it now for cooking and it'll be fine.

Thank you Snowdown. I'll do that this evening.

Have you tried the "vacuvin" bottle stopper and pump? it is a flexible cork substitute and a small vacuum pump that draws air through the stopper and I find it keeps wine fresh for at least 1 week, maybe more. They are available from Sainsburys