Foaming carpet cleaner is a crucial $5 investment for anyone who hosts parties. A quick spray after one of your guests' inevitable spills and you can move on as though nothing happened. There's no need to shy away from serving red wine on white carpet. You just need to be prepared. This may sound too good to be true, but I've used this trick many times.
After cleaning up this weekend, I started wondering how foaming carpet cleaner works. What are its active ingredients? How does it prevent staining? After reading about other effective remedies for dealing with red wine stains (e.g. Wine Away), I gather that foaming carpet cleaner uses a combination of baking soda, hydrogen peroxide, and possibly salt.
I also learned that white wine can help "neutralize" red wine stains. So, be sure to drink them together.