Part of the effect of dry-aging is the enzymatic breakdown of the proteins and fats (not really "fermentation") and the other part is the reduction in the moist

Part of the effect of dry-aging is the enzymatic breakdown of the proteins and fats (not really "fermentation") and the other part is the reduction in the moisture content of a particular cut. The loss of water weight is one of the reasons a dry-aged cut costs more. You can replicate a similar process at home by putting your cut of beef in an open container in your refrigerator (be sure to put a small rack under it to get air circulation on the bottom) and letting it sit for 3-4 days. For something like a rib roast the improvement in taste and texture can be quite significant.