To know the age of the brisket when you buy it, you need to see the case they were packed in. I've never seen a packed date on the brisket cryo pack itself. Aging is supposed to allow the meat to relax and reverse the effects of rigormortise(sp?). I hear 5 to 6 weeks is the prime age.. but again that's from the packing date, not from when you buy it.
4000 sq inch Wood Burner named Brutus - KCSB member/judge# 32129