[WIKI] Characteristics of a Good Cellaring Beer

Question

Every once and a while I come across beers that say they can be kept up to 5 years and become more developed over that time period, while other beers that are of the same style don't indicate this at all. I know that some styles are defined by how long they can be cellared, but for other styles how do you know? So my main question is:

What are the main characteristics that differentiate normal cellaring period beers from beers with extended cellaring periods? Does it have to do with the amount of hops? The amount of alcohol? The type of yeast?

EDIT: In retrospect, this looks like it would be a good wiki question since it's more of an information gathering topic than a personal, concise question.

Here is a compiled list of comments made below as well as answers found elsewhere:
Please feel free to edit this list (it is a wiki).

These are the characteristics that people have associated with good cellaring beers:

• Wild yeast beers
• High alcohol content
• Proper storage throughout the lifetime of the beer
• High SRM/EBC -- Dark Color

Styles of beers that lend themselves to cellaring:

• Lambic
• Barleywine
• Oud Bruin
• Belgian Ale
• Imperial Stout

Characteristics that can develop throughout cellaring:

• Floral hop character diminishes
• Hop bitterness diminishes, but at a much slower rate
• Flavor complexity is developed
• Malt character is developed
• Can develop sherry and port-like characteristics

Keep these characteristics in mind when selecting or designing a beer that you wish to cellar for an extended period of time.

Here's a good resource I found about cellaring.

Answer 1

Here is a good article on aging beer from Ratebeer.com

A few tidbits from the article, though you really must read it in its entirety:

Things that make a good Aging candidate

• The higher the alcohol content of a beer, the better it will age.
• The higher the acid level of the beer, the better it will age. The most wanted acid in beer is lactic acid. It is the highlight of Lambic, Gueuze, Oud Bruin, Saison and more of those. But also of Berliner Weisse, and more contemporary American tries at new styles.

Things that make a bad Aging candidate

• Beers with lots of aromatic hops (these aromatics will not last long)
• High sugar levels; the more sugar a beer has, the more prone it is to attract all kind of unwanted beasties during aging
• Low acid fruit beers (freshness of the fruit will be lost quite fast after the first few months)