It's super easy for chicken breasts to dry out while cooking in the slow cooker. Like I said, cooking on low for no longer than 6 hours will help create juicy chicken. u003cbr/u003eu003cbr/u003eAnother tip is to make sure there's enough liquid covering the chicken breasts. Chicken breasts should be more than halfway covered with liquid, and if not, you'll run the risk of dried-out rubbery chicken breasts.