Wine Preservation

[Thomas]

Stuff you spray on top of the bottle? Are you referring to a liquid chemical or are you referring to the nitrogen system?

Nitrogen is an inert gas that displaces oxygen; it is a safe way to protect wine from oxidizing. But unless you open a bottle of wine every few weeks (which is way too little, in my view) and unless you operate a "wine bar" I do not see the need for the nitrogen system. You can carefully pour the remainder of an open bottle into a smaller vessel and save for later (preferably, the next day or day after).