Aging

[Judy Wilson]

The other day a reader wrote in to ask:

With regards to food safety, the section on dry aging does not mention anything relating to whether the dark outside crust on a piece of dry-aged meat is safe to cook with but only should be cut off.

I have heard of chef's rendering this fat down to use in pastries but would bacterial activity not make it high in toxins? Could you please elaborate on the food safety issues with dry aged meat.

Chris Young answered:

Simple answer: Not a great idea to eat any part of the surface, it's not going to taste good or have a pleasant texture, but it's fairly low risk if you were to render it for the fat or cook the heck out of it for a stock.

Complicated answer: The surface will be covered in bacteria, but nearly all of these bacteria will be non-pathogenic because pathogens don't do well at refrigeration temperatures. Heating the surface hot enough to render fat out will kill all of the bacteria, so it should be fairly safe. Moreover because it was unlikely that pathogenic populations grew in significant numbers, it's also very unlikely for toxins to have been formed. Even if toxins had been formed, in the case of rendered fat, the toxin would have to be fat soluble. I don't know how many toxins are significantly fat soluble, but I would assume most are water soluble for all sorts of evolutionary reasons.

Anybody else want to chime in on this?