A weird white foam comes out of my chicken while cooking — what is that stuff?

13. What the Foam Tells You About Doneness, Juiciness, and Texture
The presence of white foam can provide some insight into the doneness and texture of the chicken. As the chicken cooks and releases proteins, it indicates that heat is penetrating the meat. However, excessive foam might suggest overcooking, which can result in dry, tough chicken. Monitoring the foam can help you gauge the cooking progress, but it’s always best to use a meat thermometer to ensure the chicken reaches a safe internal temperature of 165°F (74°C) while maintaining juiciness.