The corned beef is done when it reaches an internal temperature of 145°F
It is fully tender when a fork slides in easily
The meat should feel soft but not falling apart unless you want it shredded
A knife should pierce the thickest part with little resistance
The brisket should be cooked until the fat is rendered and the meat is no longer tough
If simmering, it is done when a fork can twist out a small piece easily
If baking, it is done when the center is hot and the meat is tender throughout
If using a thermometer, check the thickest part away from fat or bone
Rest the corned beef for 10 to 15 minutes before slicing
Slice against the grain when it is done