The three greatest – and most age-worthy – Italian wines all start with the letter ‘B’: Brunello di Montalcino (from Tuscany), and Barolo and Barbaresco (both from Piemonte). Among these, the wine that is the most obvious choice for long-term aging is Barolo, which comes from the small region that surrounds the town of the same name in the highlands of northwestern Italy. Like Barolo, Barbaresco hails from a small eponymous region in Piemonte and is composed entirely of the Nebbiolo grape. Nebbiolo is a varietal that begs for patience due to its high levels of acidity and tannin. Although some Nebbiolos are made to be drunk young, the more complex and robust varieties like those from Barolo and Barbaresco are built for the long-haul. Drinking one soon after release can sometimes be a disappointing experience – the tannins are obtuse and unforgiving, the acid puckers the mouth, and the fruit flavors are uneven. But the passage of time resolves these conflicts, resulting in deep, rich, structured layers of candied orange, leather, earth, and red fruit. A good, well-aged Piemonte Nebbiolo is a truly unique experience in the wine world, one well worth pursuing.

Bordeaux:The red wines of Bordeaux are the gold standard of age-worthy wine. Made largely with Merlot and Cabernet Sauvignon grapes in the warm, southwestern corner of France, they seem to have an inherent ability to age well. Vintages vary significantly here, but the best years will produce $100 and up wines that improve for 20 years or more, $50 wines that improve for 15 years or more and even $18 wines that will evolve interestingly for five or more years after their release.

Red Burgundy: Some red Burgundies age beautifully, but unless you buy a blue chip like Domaine de la Romanee-Conti it’s a gamble. Red Burgundy worthy $30 a bottle or more is safe for three to five years

Rhone Reds: Not as high profile as Bordeaux, but certain subcategories of wine from this French region have great track records for aging. Chateauneuf-du-Pape, Hermitage and Cote-Rotie are three of the top Rhone districts (appellations) to look for when you want a wine that shows its best stuff after 10 or more years.

Chardonnay and White Burgundy: The best wines for aging are often the most tight and tart when young, including French Chablis, the various Montrachets and Meursault from Burgundy, which in the $50 and up range can get better for five to 15 years.

One of the wine world's great secrets is the aging potential of Australian wines. Australians know about it, of course. After all, they have been making wine for as long as Californians have, and there was no Prohibition to interrupt the Aussies' winemaking history. The idea just hasn't taken hold overseas, except among a few knowledgeable collectors. Americans accustomed to drinking Australian wines in the bloom of the wines' fresh youth may find this aging potential surprising. Only a small percentage of the world's wines survive over many years of aging and develop the kind of complexity that collectors treasure. Big, rich and barrel-fermented, or steely, crisp and delicate, the best Australian wines can emerge from a cold cellar and deliver the goods with the best of them.

Many wine drinkers don’t realize that German riesling is among the most age-worthy wine in the world. The riesling grape’s low rate of oxidation combined with the high levels of acidity produced by the German terroir results in wines that routinely improve with each successive decade of bottle age.

There are three basic types of non-botrytized (i.e. non-dessert) German riesling: Kabinett, Spatlese and Auslese. Kabinett, whose grapes are picked the earliest, is the last ripe of the three styles. Typically, Kabinett rieslings are relatively dry. Auslese, whose grapes are picked the latest, is the ripest and therefore usually the sweetest of the three styles. While Auslese is sweet, it’s still fresh and crisp, not syrupy like most dessert wines. Spatlese is somewhere between Kabinett and Auslese. While you can age Kabinett with interesting results, Spatlese ages better, and Auslese ages best of all. Among German rieslings, as a general rule the riper the grape, the longer the wine can age, and the more nuanced the layers of flavors will become.