[landarc]

The connective tissue begins to render below 200°F, but, the amount of tissue will vary from animal to animal. There is no single temperature that will guarantee tender brisket. Each one will vary a bit. This is why most of us cook by feel.

However, if you had wrapped and rested that one brisket, it may have gotten better. The rest is not a good method for most folks to use to get a good product. I recommend using a probe test for most folks, once you feel the brisket is close, you probe it with a metal skewer or ice pick. If the probe slides in easily, then, pull, wrap and rest.