keep as long as conventionally processed
meats.
Rigor Mortis
The Importance of Timing, Posture, and
Temperature For a brief period after the
animal’s death its muscles are relaxed, and if
immediately cut and cooked will make
especially tender meat. Soon, however, the
muscles clench in the condition called rigor
mortis (“stiffness of death”). If cooked in this
state, they make very tough meat. Rigor sets
in (after about 2.5 hours in the steer, 1 hour or
less in lamb, pork, and chicken) when the
muscle fibers run out of energy, their control
systems fail and trigger a contracting
movement of the protein filaments, and the
filaments lock in place. Carcasses are hung up
in such a way that most of their muscles are
stretched by gravity, so that the protein
filaments can’t contract and overlap very