When cooking chicken breasts in a slow cooker, you should ensure that they reach a safe internal temperature to avoid any risk of foodborne illness. The recommended minimum internal temperature for chicken breasts is 165°F (74°C). At this temperature, the chicken is fully cooked, safe to eat, and retains its juiciness and tenderness.
Using a meat thermometer is the most accurate way to check the internal temperature of the chicken breasts. Insert the thermometer probe into the thickest part of the chicken breast, making sure not to touch any bones, as this can give you an inaccurate reading. Once the internal temperature reaches 165°F (74°C) or above, the chicken breasts are considered done and safe to eat.
If you are cooking the chicken breasts along with other ingredients in the slow cooker, it's also essential to ensure that any vegetables or other components in the dish reach a safe temperature as well. Following the recommended cooking times and using a meat thermometer will help you achieve perfectly cooked and safe chicken breasts in your slow cooker recipes.