During the ageing process, proteins that give muscles form and functionality start to be broken down by enzymes left in the body after slaughter. As these larger proteins disassemble into smaller ones, meat becomes more tender.

This action happens in the process of both wet ageing meat and dry ageing meat; however an added feature of dry ageing is a change in meat flavour.  As a general rule, the longer this chemical process takes place, the more tender the meat becomes, however there is a point when tenderisation plateaus and there remains little improvement.  Ageing does nothing to tenderise heavy connective tissue in meat- to do that, requires slow moist cooking or acidic marinades.