Inexpensive Wine Preservation Systems
Rebottling Your Wine
The simplest and cheapest option to preserver your wine is to transfer the leftover wine into a smaller bottle, filling it up to the top and then placing a stopper in it. This will remove most of the air from the bottle and is said to extend the life of the wine for a couple of days, however you should always transfer the wine no longer than an hour after you have finished drinking it to give it some chance of holding up.
If you don't have a smaller bottle to transfer the wine into, then you can always use marbles to preserve your wine by filling up the bottle before placing the closure back on. Once again this may extend the wine for a couple of days, however the marbles may become a problem when you go to pour the wine again.
The Wine Preserva wine preservation system is an Australian invention where an inert plastic floating disk is inserted into the open bottle and floats on top of the wine. The disk acts as a lid on the liquid's surface, preserving the flavour and aroma of open wine for up to five days.
PlatyPreserve works by you transferring your un-finished bottle of wine into an air tight reservoir. You pour the wine into their container, squeeze all of the air out, and then tighten the cap to seal out air in the PlatyPreserve. They claim it can preserve your wine from several days to even weeks later.