Basting is spooning pan drippings or liquid over roasting meat, but it is not strictly necessary for a juicy roast and can even hinder crispy skin due to frequent oven door openings that drop the temperature.
Basting involves regularly spooning or brushing the pan drippings, melted butter, broth, or other liquids over a piece of meat (most commonly poultry) as it roasts in the oven. The traditional belief is that basting keeps the meat moist and contributes to a better flavor and more even browning of the skin. However, modern culinary understanding suggests that basting is often more effort than it's worth for juiciness, and can even be counterproductive for achieving crispy skin. Each time the oven door is opened to baste, the oven temperature drops significantly. This extends the overall cooking time and can make it harder for the skin to dry out and crisp up. For poultry, the natural fat beneath the skin renders during roasting, effectively 'self-basting' the meat. The primary factors for a juicy roast are cooking to the correct internal temperature (avoiding overcooking) and allowing sufficient resting time after it comes out of the oven. While basting might contribute to a slightly more flavorful or deeply colored skin for some, it is not essential for maintaining internal juiciness.
Instead of basting, consider rubbing butter or oil directly onto the chicken skin before roasting for browning, and add aromatic vegetables and broth to the bottom of the pan to create flavorful pan drippings for gravy.