How Long to Cook BrisketOr Misconception of the 1 to 1.5 hours per pound rule This is not just my opinion, but facts gathered from various sources. One has Ph.D. in Physics from Harvard University, Texas A &M Agrilife Research & Animal Science, Texas A & M Rosenthal Meats Center and Teach Meat Science, Department of Animal Science, and TAMU BBQ group. Also, my observations of forty years of smoking. I am not trying to step on anyone’s toe’s or create a problem, just trying to help first time smokers in their journey to smoking a great brisket In general thickness is a better predictor than weight. Imagine you had one 20” long, 10” wide, 3” thick brisket. Weighs 20 lbs, and takes 30 hours to cook. But now imagine you cut in half, and separated it by an eighth of an inch. Would it take 30 hours to cook, or 15 hrs now that each half weighs 10 lbs? In fact, the cooking time only depends on the brisket thickness, not its weight. A 30” long or a 10” long brisket that is the same thickness takes the same amount of time to cook. Similarly, a 6” diameter pork but that is 12” long cooks in the same time a 6” diameter 18” long butt. So if you typically cook a 12lb brisket in 12 hours, and you bought an 18 pounder but really it is just longer and about as thick after trimming, the cooking time might only jump from 12 to 13 hours..... 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, they both weigh a pound, but which one will get to medium rare the quickest. That is why so many people new to smoking have their briskest turn out dry, tough, over or under cooked, because they are going strictly by time. After you have cooked several briskets and are familiar with your smoker it is a lot easier to judge when your brisket is done. A thermometer is a valuable tool. Check your brisket at different intervals and when you think it is getting close. 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. So to summarize, when picking a brisket take note of the size differences a 16 pound brisket is going to be bigger all around, a little thicker, wider and longer than a 12 pounder, so take that into consideration when choosing and smoking a brisket. I wouldn’t automatically add 6 more hours for the 18 pounder, but look at how much thicker it actually is and use your good judgment. I know smoking a brisket for the first time seems complicated for some, but keep it simple watch your temp and keep an eye on your brisket 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 finger tips, that wasn’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 briskets are exactly the same, let’s say for example you estimate 1 to 1.5 hours per pound. A 12 pound brisket can be done in 12 hours during one smoke and the same size brisket takes 18 hours 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. Good briskets 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. (Most briskets that are dry and tough were not cooked long enough) Most briskets will be done around 190° to 205°. Now if you buy” Choice grade” it can be tender and juicy around 180° to 185°. Beef needs to rest after it is cooked so the juices can redistribute before cutting. A brisket should rest at least 30 minutes and up to 2 to 4 hours in a warm ice chest. Using the 1 to 1.5 hour rule and your brisket is around 12 pounds, a cooking time of between 12 and 18 hours depending on the above mentioned factors. A lot of cooks use the toothpick test, when the toothpick slides in like butter with no resistance its ready. Another method mostly by experienced cooks and have a lot of briskets under their belts, is looks and feel, a good bark and kind of soft and pliable. I am hoping this helps and not confuses anyone, Smoking a brisket is not rocket science but you need to pay attention to the basics and you will have great brisket.