One area of concern that I had when bottling a batch of wine was the case where I didn't have enough wine to completely fill the bottle. This could result in possible oxidation of the alcohol to vinegar over time. To avoid this issue, I came up with a simple solution. I bought a small (5-lb) size CO2 bottle, pressure regulation, appropriate fittings, and plastic tubing from Amazon to make a purging system. I took the empty CO2 bottle to my local welding-supply dealer and had it filled for a very small fee ($10, I believe). When I end up with a partially full bottle of wine, I just purge the air out of it for several minutes with this system and then cork or seal the wine for long-term storage. I've attached a picture of the setup that I made.
Another advantage of the purging setup is that it allows you to make your own fizzy (carbonated) water (or juice). With the appropriate plumbing and an appropriate PLASTIC bottle---like the 2-L soda bottles--you can easily make your own fizzy drinks. You should not try this, however, with standard wine bottles, as the glass could shatter and injure you if you overpressurize the bottle. I find that a pressure of about 20 psig works great with the soda bottles and this is in the same realm of pressure in a standard bottle of soda. With additional fittings and a valve, I can fill a glass without having to open the bottle each time, which quickly drains off the pressure.
To keep an opened bottle of wine protected from air when the bottle may not be consumed in a short time, I find that the Vacu Wine Saver from Amazon works quite well. It uses a special rubber stopper that allows you to pump the air out of the wine bottle for short-term storage.

Another advantage of the purging setup is that it allows you to make your own fizzy (carbonated) water (or juice). With the appropriate plumbing and an appropriate PLASTIC bottle---like the 2-L soda bottles--you can easily make your own fizzy drinks. You should not try this, however, with standard wine bottles, as the glass could shatter and injure you if you overpressurize the bottle. I find that a pressure of about 20 psig works great with the soda bottles and this is in the same realm of pressure in a standard bottle of soda. With additional fittings and a valve, I can fill a glass without having to open the bottle each time, which quickly drains off the pressure.
To keep an opened bottle of wine protected from air when the bottle may not be consumed in a short time, I find that the Vacu Wine Saver from Amazon works quite well. It uses a special rubber stopper that allows you to pump the air out of the wine bottle for short-term storage.
