Dry Aging a Sirloin

[Ron Pratt]

Not quite sure what you mean by “flap” but if whatever it is is small then trying to age it by itself will probably be a waste of a bag and your time. If your sirloin has obvious excessive fat then yes trim that. My last one I trimmed over 1 pound of excessive fat. By chance are you seeing a vein of meat running thru a huge layer of fat which you are referring to as a flap? Can you post a picture? Ron