Your wine's worst enemy is not your imbibing mother-in-law... it is air. You should do everything in your power to prevent air from ever contacting your wine. Okay, yes, well there is one time you have to let air touch it, but you know what I mean. If wine is uncorked and not drunk within a few days, it will get funky.

Evil Air Lesson 1: Oxidization. Oxygen may be good for little children and bunny rabbits, but it is bad for most everything else. If wine is not stored or sealed properly, it will develop both an oxidized color and flavor.

Cool Bean Fact: This is why you see the stodgy old guy in the movies hold a glass of wine up to the light and stare at it as if expecting to find a dead goldfish floating there. He's checking the color and clarity.

Red wines should have a beautiful ruby color. Whites should be light greenish to yellow, never dark. If there is any hint of orange or brown, you may have bad wine. It should also be clear. Cloudy wine is a bad sign, but a little floating sediment is okay.

The smell and flavor of the wine will be the most obvious giveaway. Oxidized wine will taste funny. Since it is absolutely impossible for me to tell you how this actually tastes, you should order a small glass of dry sherry from your local restaurant. This is oxidized wine. I know, I know, "why is sherry oxidized if oxygen is so evil?"

Sherry, and a few other wine-based drinks are the only exception to the rule. Sherry has a highly controlled oxidization process which makes it suitable as an aperitif (look it up). This is never desirable in table wines.

Evil Air Lesson 2: Spores, molds and bacteria. This should be an obvious lesson to most. Even the cleanest air contains all of the above, and is going to be in the bottle with your opened wine. It is random luck, of course, but give it a week and I promise the wine won't taste as good as the first night. The alcohol content of most wines will not inhibit the growth of these space creatures.

Evil Air Lesson 3: Aeration. Now back to the one time you actually want air to touch your wine. When you get ready to open that bottle of fine wine to serve yourself or friends, it is usually a good idea to aerate the wine by either leaving the opened bottle for several minutes, or (the better way) carefully decant the wine into another container. This process allows the wine to finally "breathe" and release the wonderful aroma and flavor that you enjoy. You can't keep it bottled up forever. This is the moment. Seize the Day!

Previous: Fundamentals
Next: Ageing - does it really matter?

Jason W. Moulder T.E. (Thoroughly Educated) is an expert in wine. He once read the back of a cookbook on the subject, made 5-gallons of home brew, and has also worked part-time at a liquor store. Plus he drinks, oh, lots of the stuff.