I have been asked the question, "How long should I age a bottle of wine before opening it?" Wow, this question is going to make my brain hurt because there is no pat answer. I think I would like to answer this question by saying that wine is a living thing and like humans some of us age better than others (Could our age factor have anything to do with how much wine we drink?).
White wines usually do not age as well as the reds because they contain little or no tannins However, there are a few exceptions such as Rieslings, better-made Chardonnays and Chenin Blancs. Personal experience has showed me that a well-made Chenin can really age quite lovely for several years. For inexpensive white wines, I say "drink up!" There really isn't much benefit to letting them age. Better-made whites can age anywhere from around 4-8 years. Rich dessert wines like Port, Sauternes and late-harvest whites will usually do very well with age. Color is important to understand about aged wines. The clear white or light yellow wine will turn a amber honey color with age. Red wines will often turn a rich copper color.
I am always telling people that if they want to truly see how a wine is going to age, then buy a case of that wine. For the first year or so, open a few bottles here and there and then open a bottle once a year. The most important thing is to journal your tasting notes and dates everytime you open a bottle of that wine. As you look back into the years you will see how the wine evolved. Remember, there is always the peak time for that wine and in later years it could become flat, brown in color and later "dead." (And no -- wine past its time rarely turns to vinegar - - and that's another blog entry for another time.) Again remembering that wine is a living thing.
And no - - there is nothing wrong with a wine that has sediment in the bottle. In fact, sediment can sometimes indicate a superior wine. Sediment (wine diamonds) is fine deposits that are found in wine once it has settled. It can be found on the bottom of the cork, on the side of the shoulders and bottom of the bottle. This settling is exhausted yeast cells and grape skins (tannins). It can also show that the wine has not been overly-processed or fined. Wines that have not been over-processed is a good thing.
Last but not least, to give your wine it's full aging power it is going to make a difference on how you stored it. Wine prefers the dark and temperatures of about 45 - 60 degrees. Remembering again that wine is a living thing and when you remember that and are considering storage - - how would you like to live in a small kitchen cupboard above your refrigerator?