Originally Posted by HighPlainsDrifter
Really? I've heard of resting a steak but never pork. What does it accomplish?
If you monitor the internal temp of you butt, you will see that it stays in the 160 deg range for most of the 10-12 hours it takes to cook. During this time the fat is basically melting.
When you pull your butt off the heat the fat is still liquid. An hour rest in a cooler allows the meat to slowly re-absorb it. Fat = flavour, you don't want to lose it.
I just use a towel, no foil. The foil holds in the moisture and makes the meat soggy.
One more point, if you're not already doing so, use a meat thermometer, not a clock, to determine when your butt is finished. 190-200 deg is the general rule of thumb.