If I wanted to roast a pork butt at 215 deg F, how long would I do this for? In 600 pan, foiled, salt crusted on a rack.
You want an internal temperature of at least 145°F or 63°C for rare slices up to 195°F or 91°C to get a disintegrating pulled pork.
How you get there and at what temp is very subjective. If you're oven roasting at 215°F then you're in for a 6-14 hour cook time depending on the mass of your roast. You'll get a wonderful, slow cooked meat, but prep time and temperature monitoring become vital. Sous Vide will cook at an even lower temperature; as low as 120°F over 24 hours, but I really don't like that method. Too much time for food born illness bacteria to form.
I like to make pulled pork, that's done around 195°F - 200°F internal temp, but a 7-8 lb roast will take almost 12-14 hours cooking at 215°F oven temp.
I usually cook Pork Butt (or Boston Butt) for around 20 to 25 mins per pound
This link http://m.recipetips.com/kitchen-tips/t--907/pork-cooking-times.asp has a list of suggested cooking times.
I usually do my pork at around 160f to 180f. And would worry that cooking at such a high temperature would mean the meat would be over cooked on the outer parts before the inner part was cooked, meaning some of the meat might be quite tough.
If your pork is covered in foil during cooking, you are looking at roughly between 1 and 1.5 hours per pound if you are looking to make pulled pork, 30-45 minutes per pound if you are looking to slice it.
The most important thing to note is these are just guideline times, intended to aid in planning. You should begin checking your roast as you reach the low end of the approximate time window. For example, let's say you have a 5 pound pork butt which you are going to roast in the manner you have described. This means that if you are trying to make pulled pork, you will start checking your roast at the 4.5-hour mark. You will want a skewer or similar probe to slide in and out of the meat with zero resistance. Or if you are making sliced pork butt, you will start checking your roast at the 2.5-hour mark, and your probe should be met with some slight resistance.
General food safety standards would tell you pork needs to be cooked to a internal temperature of 145F. You are probably gonna be cooking for a while if the oven only goes to 215, with the real possibility that it will not get there.
If the temprature goes up in parallel with the time going down then the temprature only needs to be adjusted to cater to the cooks patience. If you fear a dry piece of swine then some time in a brine may be great for it. Brings just typically take some of the guess work out of cooking times.
Modern pork is pretty lean, somehow lean pork has stopped being an oxymoron. So it does pretty well in a brine.