Why do beef briskets and pork butts benefit from cooking to 190 to 200°F internally?

Beef briskets and pork butts are two of the most popular barbecue cuts, and both of them have a high percentage of connective tissue containing collagen. Collagen is converted to gelatin when heated (this is how Jello® is manufactured), and it requires a higher internal temperature (ranges from 190 to 200°F) to achieve this conversion.

Although the muscle fiber component of tenderness gets tougher as internal temperatures go up, the connective tissue component of tenderness becomes more tender. Fall-apart barbecue such as pulled pork is achieved because the connective tissue has become soluble from cooking. Failure to reach this endpoint will result in tough barbecue.