[Pinner]

I've always heard 195 min. Just sayin

In the book How To Cook Meat, authors Chris Schlesinger and John Willoughby say that tough cuts of meat must be "cooked through doneness to tenderness." In other words, you don't stop cooking a pork butt when it reaches the internal temperature we associate with tender cuts like pork loin or pork tenderloin. A pork butt is not edible if cooked to 140°F or even 170°F.

In order to be tender, a pork butt must be cooked to an internal temperature of 180-205°. The reason for this, according to McGee, is that the conversion of collagen to gelatin doesn't even begin until meat reaches an internal temperature of 140°F, and is most efficient as internal temps approach 212°F. "Low and slow" barbecuing at 225-250°F is ideal to facilitate this conversion, providing gentle heat over many hours, allowing the collagen to make its transition into gelatin. While some moisture will be driven out of the pork butt as it reaches these high internal temps, the gelatin makes up for it and keeps the meat moist.

For sliced pork, cook to 180-185°.
For pulled pork, cook to 190-205°.

http://www.virtualweberbullet.com/porkbuttselect.html