according to the Wine Guy...
First, the philosophy...
Nary a week goes by that someone doesn't come by the store to ask about purchasing a large format wine storage unit or building a wine cellar.   Being a wine merchant, I know that I should do everything I can to encourage wine cellars, since so many of my customers spend money in our store in an effort to fill them.  I have maintained a personal cellar for over 15 years and can personally attest to the pleasure to be derived from opening a bottle of 12 year old Cabernet that has aged to mellow perfection.  The warmth you feel as it spreads its velvety richness across your palate is only rivaled by the sense of victory you have earned by your patience.
 
Well, there is also a dark side to wine cellars, like the engraved anniversary magnum of a 1990 Sausal Zinfandel that we opened last year.  It was rich and filled with fruit in its youth, but had withered into dull senility over 13 years.  The fact is far more wine is ruined in the finest wine cellars than is ever preserved.  I cannot tell you the number of times I have watched the owners of magnificent wine cellars discard the rust colored liquid contained in what was once a prized bottle.  The truth is that no one can consume 3,000, 5,000, or in some extreme cases, 10,000 bottles of wine before a good portion of it goes bad.   Not only am I certain that a high proportion of the cult wine and first growth Bordeaux's are collectables that will never be consumed, even many fine Cabernets and Pinot Noirs are routinely held well beyond their prime....
 
It took me a long time to understand that wine is like a living thing.  It is born, enjoys an exuberant youth, gradually reaches the peak of its maturity and then slowly fades away to vinegar.  Think of it as a bell curve...  a fine bottle of Napa Cabernet might have a twenty year life and reach its own level of perfection at the eight year mark before slowly fading away to an amber colored death in its 20th year.  This is true for all wines, with a vintage Port lasting 50 years or more, while an Italian Pinot Grigio might barely hold on for two. 
 
The primary reason for maintaining a cellar should be to provide yourself with a well chosen selection of wines that ensure that you always have the right wine for the right occasion.  A wine cellar gives you the luxury of constantly selecting wines that you can allow to mature for future consumption.  The secret is to keep your selections in balance.  You need to think about your own consumption profile.  What is your of ratio reds to whites... how about between varietals and regions?   Think about logging the wines you consume over a few months and use those proportions to dictate the kind of balance you want to achieve in your cellar.  And, this should be done while taking into account the potential maturity of the wines.  While you would never want to hold Sauvignon Blanc more than a year, you will need to be thinking 5 to10 years down the road as you select ageworthy Cabernet Sauvignon.   So, before you embark on building a personal wine collection here are a few thoughts.


1.) Is it the thrill of the hunt?  If finding the truly great bottles is your goal, save room, because there is a "vintage of the century" going on somewhere almost every year!

2.) Don't cellar more than you can drink unless you intend to sell it off before it's too late.

3.) Don't  forget when to drink them. Always label your bottles with a tag that reminds you when you intend to serve them.  (shameless plug - the cellar cards available here at Grapevine Cottage do this pretty well)

4.) Sample your wines over time.  Don't wait 10 years to try the first bottle in a case.  The top of the bell curve is very elusive.  If I have case of good Cabernet, I might wait a year and start trying a bottle a year until I think it has peaked, then consume the rest over the following 12 to 18 months.

5.) Remember, modern wine making styles lean toward shorter and shorter maturities.  Take into account the timelines provided in magazine reviews and pay close attention to the level of tannins in reds and acids in whites. Generally, longevity in white wine is all about acid just as ageworthy reds are based upon their tannic structure.    
 
And, the nuts and bolts of wine storage...
How you choose to store your wine should be dictated by how quickly you want it to mature.  Here are the factors involved in order of importance.  
 
Temperature
A red wine stored at 70 degrees will probably age twice as fast as one stored at 58 degrees and white wines are even more affected, often maturing three times as fast.   While a 55 to 58 degree cellar temperature is optimum, a 60 to 65 degree quiet corner will do fine for short term storage (2 - 3 years). Remember, the warmer the storage, the quicker the wine will mature and then deteriorate.  Consistency in temperature is most essential, and any changes in temperature should occur very slowly.  White wines are much more fragile than reds and are much more sensitive to heat.
 
Humidity
Moderate humidity is important to keep corks in good resilient condition.  A relative humidity of 50% to 75% is ideal.  Humidity higher than 75% percent will cause the labels to become moldy and deteriorate.. Humidity below 50% can potentially dry out the corks and shorten the life of the wine.
 
Darkness
Light, especially ultraviolet can prematurely age wines.  Sparkling wines are especially light sensitive and can be adversely altered by light exposure.  Your wine storage should ideally be dark whenever you are not using it.
 
Vibration
Consistent vibrations from machinery or nearby roads can disrupt the aging process and damage your wines, especially reds.
 
Racking
Your wine should always be stored horizontally so the wine stays in contact with the cork.  Bottles should be stored with the labels facing up so that sediment deposits can be seen while decanting.
 
Temperature Controlled Wine Storage Units
These are a whole different subject that I will not attempt to cover here. However, since I own one, I should offer some words of caution.  They work fine, but...

1.) Never believe the capacity claim.  I have a Vino Temp VT200 that claims to hold 182 botlles. It actually holds about 150.  I am sure it would hold 182  perfect 13" Bordeaux  style bottles, but the reality is that it holds about 150, if I'm lucky.

2.) My unit came from Cosco and while I am sure it was a bargain, if it wasn't in our lower level Linda would have made me take it back beacuse of the noise the compressor makes.  If you are going to locate a unit anywhere near where you actually live, spend a little more money and go for a quieter model.