How Long Is Too Long To Cook A Roast In The Slow Cooker?

Cooking a pot roast in a slow cooker is arguably one of the best ways to prepare it. The end result is incredibly tender, melt in your mouth, flavorful meat that is juicy and succulent — all because of how that low and slow approach lets flavor build and meat tenderize. But, while you might be tempted to leave a roast in a slow cooker longer to see how much better it might get over time, you should save yourself the trouble of a dried out, textureless roast and stick to recipe guidelines. You can absolutely overcook a roast in a slow cooker, and if you go beyond 12 hours, odds are you'll end up with a pretty disappointing meal.

A good rule of thumb for most cuts of beef is to slow cook on the low setting for about two hours per pound. A slow cooker is designed to bring food up to just below boiling temperature, about 209 degrees Fahrenheit. On the low setting, it can take eight hours to do this with a 4 pound roast. For a very tough cut of meat that you're trying to tenderize, however, the total cook time can be between 10 and 12 hours.  By that time, the fat will have rendered and the collagen broken down – leaving you with a roast that tastes and feels the way you want it to. Any longer, and you could end up with a dinner that's dry and disappointing.

Whatever cut you choose for your pot roast, the longer you cook meat and the higher the temperature, the more moisture it will lose. It doesn't matter if you have it immersed in liquid, the muscle fibers themselves no longer hold that moisture inside. So while you can have adequately sauced meat, the meat itself won't be moist. It will just be wet — and there's a big difference. 

The protein in muscle fibers denatures at higher temperatures, forcing moisture out of the meat. If this is allowed to go on for too long the fibers shrink, toughen up, and dry out — a process you can't reverse. The cut and size of your roast determines how long it needs to cook, but if you go too far beyond that you can reduce the meat very nearly to mush. Think of pulled pork taken to the next level — it's dry and falls apart, without any desirable texture. 

If you're not sure how long to slow cook a roast, your best bet is to follow a reliable recipe — being wary of any that recommend cooking beyond 12 hours. Tasting Table also has a go-to method for a delicious slow cooker pot roast ever time that you can try.