I posted a similar thread on Briskets (The 1-1.5 hour rule) so some of
the references are similar.
In general thickness is a better predictor than weight.
Imagine you have a 10” long, 10” wide, 8” thick butt that weighs 10 lbs., and takes 15 hours to cook. But now you cut it in half, would it take 15 hours to cook, or 7.5 hrs. now that each half weighs 5 lbs.? In fact, the cooking time only depends on the butt thickness, since it weighs 5 lbs. and is only 4” thick the Butt will cook a lot quicker.
So if you typically cook an 8lb butt in 8 to 12 hours, and you bought a 10 pounder that is really just longer, wider and about the same thickness, the cooking time may be the same or might only increase an hour or so…..
Another example, Say you are grilling steaks, you have two pieces of meat, both weigh one pound but one is an inch thick and the other is two inches thick, you are cooking both to medium rare, but which one will get to medium rare the quickest ?
Also Smoking temperature is one of the key factors, people smoke anywhere from 200° to 300° so how can your cooking time be based on weight, simply put it can’t. The one hour per pound rule is a good starting point, but don’t base your entire cook on weight alone.
I know smoking a butt for the first time seems complicated for some, but keep it simple watch your temp and keep an eye on your butt and you will be fine. I guess it’s easy for me to say since I’ve been smoking for over 40 years.
There is so much information available at your fingertips that weren’t there when I started. I had a lot of trial and errors; ask a lot of questions at different BBQ joints and friends who smoked. I also kept a notebook which I would refer to until I got comfortable enough not to need it any more. When I switched to a reverse flow (which I use now) it took a few smokes to get to know my new smoker and figure out the adjustments. I have smoked so much on it I know when to check it to add wood or more charcoal, how much to start with and how quickly it comes up to temp.
No two butts are exactly the same, let’s say for example you estimate 1 to 1.5 hours per pound. A 8 pound brisket can be done in 8 to12 hours during one smoke and the same size brisket takes 16 hours or more the next time. Why? There are many factors that contribute to the difference; type and breed, diet, age of the animal, amount of exercise, feed, etc. All these determine the density of the muscle and the amount of fat marbling. Type of equipment, experience level, temperature, and weather all play a part in how long it will take.
Butts take time, but the time varies, so how do you know when it’s done?
There are several methods you can use. One way especially for the beginner is use a thermometer. Also get a hold of the blade bone and wiggle it, If it is done it will slide right out. The internal temp is usually around 205 ° Butts generally fatty enough that they don’t dry out. I usually let my Butt rest for about 30 min or longer to redistribute the juices. Or you can just pull it in a pan capturing all the juice.
Most of my smoking is done at 225 º Some people smoke at higher temps. The 225 º just seems to work best for me.
I am hoping this helps and not confuses anyone, Smoking a Pork Butt is not rocket science but you need to pay attention to the basics and you will have great smoke.
Here are a couple of links on Pork Butt
Bearcarver does his on an Electric http://www.smokingmeatforums.com/t/140055/boston-butt-pulled-pork-step-by-step
I do mine on a Reverse Flow http://www.smokingmeatforums.com/t/176104/pulled-pork-ribs-beans
Edited by gary s - 5/12/15 at 9:20am