Dear Peggy: Is it safe to cook a large roast in a slow cooker? —A.S., Columbus, Indiana
Yes, with some precautions. Large cuts of meat, such as roasts or whole chickens, can stay in the "danger zone"—a range between 40° and 140°—for too long.
This allows food-borne, disease-causing bacteria to multiply in substantial numbers. Some types of bacteria produce toxins that remain in the food even after it's fully cooked. The longer that food stays in the danger zone, the greater the risk that bacteria can multiply and produce more toxins.
For food safety, many cooks sear roasts in a hot pan before putting them into slow cookers. Searing browns the meat, providing full, intense flavor and a richer color, and it kills the majority of the bacteria on the meat's surface. But it doesn't offer 100 percent protection.
For that reason, we always cut larger roasts into smaller pieces in our recipes. This allows them to pass more quickly through the danger zone.