1. What is the basic hours to pounds ratio to judge cook time at 250 degrees?
I allow a little more time, around 90 minutes per pound. If you get done sooner, great, but, allowing for the stubborn butt is always a nice thing. You can hold a butt done early, but, a stubborn butt, that just makes you look bad.
2. What is a simple at home rub I can make? I don't have any commercial rubs.
I like to use fancier rubs, but, here is what I often default too, when all other things fail. All measurements by weight
3 parts Kosher Salt
2 parts medium grind black pepper
1/2 part chile powder
1/4 part each Turbinado sugar, granulated onion, granulated garlic
3. What internal temp should I foil the butt?
If I am going to wrap in foil, I wrap by color and not internal temperature. When it hits the right color, wrap in foil. If in paper, I have found the color darkens some, so I foil when it is a little lighter. No need to wrap actually.
4. Does the pork butt need to sit in a cooler after the cook? If so, how long?
I like to rest it in a cooler or the oven, for at least 2 hours. It can easily go four hours.
On edit: Do not forget, if you wrap it, vent the foil for 15 minutes or so, to stop the cooking and let some steam out. This will not cool things down hardly at all, but, if you cook until the bone wiggles, then do not vent, the carryover heat can lead to some mushy pork.
