What's the deal with aged beef?

[cor]

I was scoping out the menu at John Besh's Steakhouse last night, and the most expensive thing on the menu is a 30-day aged sirloin.

This might be a very ignorant/uneducated question...but what IS aged beef?

[SiksElement]

also weight loss from moisture evaporation. less water=more flavor concentration

[Sam Fujisaka]

Dry aged beef is hung in large (primal) cuts at near freezing, dehydrating the meat; as enzymes (and othr micro-organisms?) work to tenderize the meat. High cost reflects the weight loss and the loss from cutting off moldy surfaces.

[mpalmer6c]

Just what the name says. When beef is aged (under correct conditions, of course), it becomes tastier and more tender. Here’s some info:

http://www.goodcooking.com/steak/dry_...