(
News Canada) - According to Health Canada, research has shown that the colour on the inside of a burger is not always a reliable indicator of how well it is cooked. For example, sometimes previously frozen ground beef burgers turn brown in the middle before they reach a temperature high enough to kill harmful E. coli bacteria. Sometimes burgers may still have a pink tinge even if they have reached the safe temperature of 71°C (160°F). Health Canada recommends using a digital food thermometer to know when your ground beef is safe to eat.