How long to let a brisket rest
In general, as you start to finish your brisket after smoking it for several hours, you’ll want to understand how long you should be letting it rest before you start slicing into it. On average, most briskets need to be rested for about 3 to 5 hours. That is just so the internal temperature has a chance to come down from 200 degrees Fahrenheit to about 165 degrees Fahrenheit.
If you decide to slice it the second you take it off the smoker, all of the juices and tenderness and moisture will evaporate. You don’t want anything to evaporate, you’ve already worked so hard to create an amazingly juicy brisket, and you don’t want all that effort to go to waste if you make the simple mistake of slicing too early.
A great way to let it rest for that extended period of time, is to just grab an ice cooler or some type of warming oven inside of your house, and place it inside of there for at least three to five hours. Monitor the internal temperature every 30 minutes and check to see where it’s at. You want it to be at least 165 degrees Fahrenheit before you cut into it. Once it’s at that point, then you can take it out and begin slicing it for yourself and others.
As a helpful rule of thumb, you’ll want to let any brisket, no matter what kind of weight it is or type of brisket it is, rest for about 3 to 5 hours. That’s the average time that I’ve seen these cuts of meat need to be rested for. Anything shorter than 3 to 5 hours, and you will risk severely drying it out and letting the moisture evaporate simply because the internal temperature is way too hot.