Ageing enhances beef two-fold: flavour and tenderness. That said, 
it’s an expensive process as you lose about half the weight between when it arrives from the butcher and when it’s served on your plate.

“People will criticise our prices, comparing us to what beef goes 
for a kilo at their local supermarket,
 but not knowing that we’re selling half of what we brought in,” says Giorgio Nava of Carne SA restaurant 
in Cape Town.

Still, what it loses in weight it makes up for in a greater concentration of taste and tenderness. Steve Maresch, chef and owner of The Local Grill in Joburg, explains the two ageing processes:

Dry Ageing
Meat is left in a cold room where it dries out and loses up to 25% of its weight in water, which makes it more concentrated in taste. Enzymatic processes inside the meat break down muscle and tenderise it from the inside out. The constant flow of air around the meat results in a dark patina on the surface, which is then trimmed off. Expect a mineral-rich taste that will intensify over time until taking on an almost blue 
cheese taste.

Wet Ageing
Meat is placed in a tight vacuum-sealed bag where it lies in its own juices. The enzymatic processes take place and after being removed from the pack after 30-40 days the meat has been infused with its own juice. It’s easier and more economical, but the taste just isn’t the same.

The Ageing cheat
Want to give your steaks more oomph without springing for the dry-aged stuff? Here’s a simple seasoning trick: add a few shots 
of high-quality soya sauce to your marinade, or forgo the marinade 
and just lay your steak down in a puddle of soya sauce for 30 minutes before cooking or grilling. (Be sure 
to blot the meat dry before applying heat.) The soya imparts what the Japanese call umami – the fifth taste sense, a rich but subtle flavour that mimics the savoury, nutty flavour you find in steakhouse beef.