In general, people typically add room temperature or cold liquids to a slow cooker. Adding hot water directly to a slow cooker is not recommended as it can lead to safety issues and may even cause the ceramic insert to crack or shatter due to rapid temperature changes.
Here's why adding hot water is not advisable:
Safety Concerns: When you add hot water to a slow cooker, the temperature of the slow cooker increases rapidly. This can promote bacterial growth in the ingredients as they take longer to reach a safe cooking temperature.
Ceramic Insert Damage: Most slow cookers have a ceramic insert, and sudden temperature changes can cause it to crack or break, rendering the slow cooker unusable.
Uneven Cooking: Adding hot water can disrupt the cooking process, leading to unevenly cooked food.
For best results, use room temperature or cold liquids in your slow cooker. If you are using hot ingredients, such as seared meat or sautéed vegetables, it's a good idea to let them cool down slightly before adding them to the slow cooker to prevent these issues.
Always follow the specific instructions and guidelines provided by your slow cooker's manufacturer to ensure safe and effective cooking.