After doing a little bit of research (by little bit, I mean going to google, typing 5 words in the search bar and opening the first 2 links) I have found out why chicken breasts aren’t the best choice of meat to cook in your slow cooker (see my post about the Greek chicken). I have known that it doesn’t turn out that great for a long time. But I’ve never really understood why. Now I do. I feel so empowered. Do you want me to explain it to you? Too bad, I’m going to anyway.
There are two ways of cooking food–dry heat and moist heat. Dry heat includes baking, roasting, and grilling. Slow cooking uses moist heat. The slow cooker is best for meats that have a lot of connective tissue and that are very tough (and typically fairly inexpensive). The connective tissue is turned to gelatin after slow cooking in moist heat for several hours. That is why tough meats become “fork tender” in the slow cooker. Chicken breasts have very little connective tissue; that means they can be cooked quickly because the long cooking time needed to soften connective tissue isn’t necessary. They also have little fat, which means they can become dry if cooked too long.
So that is the science behind it. I hope this helps. Although chicken breasts don’t work that great in the slow cooker bone-in chicken works great. If you’re scared of bones use boneless, skinless thighs.