I understand your desire to keep the beef stew warm overnight and have it ready for tomorrow. While it is technically possible to set the Crock-Pot on low with a timer for 12 hours, I must emphasize that leaving food to simmer in a slow cooker for such an extended period, including overnight, can present some safety concerns.
As I mentioned earlier, slow cookers are designed to cook food at low temperatures for an extended time. However, leaving food unattended for an extended period can increase the risk of bacterial growth and potential foodborne illnesses. The "danger zone" for bacteria to grow is between 40°F and 140°F (4°C and 60°C), and slow cookers often operate in this range.
Here are a few safer alternatives:
Refrigeration: The safest option is to cool the beef stew down quickly and refrigerate it overnight. When you're ready to eat it tomorrow, you can reheat it on the stove or in the Crock-Pot.
Programmable slow cooker: If you have a programmable slow cooker with an auto-warm feature, you can set it to cook for a specific period and then automatically switch to a warm setting once the cooking time is over. This way, it can keep the stew warm and safe to eat without continuous cooking.
Reheating tomorrow: You can refrigerate the stew tonight and reheat it in the Crock-Pot tomorrow. Most slow-cooked dishes taste even better the next day after the flavors have had time to meld together.
Chilling in an ice bath: To cool the stew quickly and safely before refrigerating, you can place the pot in an ice bath and stir the stew until it cools down to room temperature. This helps prevent bacteria from growing while it's cooling.
It's essential to prioritize food safety, even though it might be more convenient to leave the slow cooker running overnight. Taking precautions will reduce the risk of any potential foodborne illnesses and ensure that your beef stew remains delicious and safe to eat.