The Only Reason You Should Open The Lid When Making A Slow Cooker Meal

Only open a slow cooker to thicken soup or sauce

Slow cookers are designed to operate at lower temperatures compared to your oven. However, opening the lid is akin to opening the oven door: heat escapes, and the food stops cooking. For most dishes, it's best to keep the lid closed. That said, you can and should lift the lid if you need to thicken something like a soup or sauce. Prop the lid open to allow moisture to escape through evaporation.

As a slow cooker prepares food, steam rises and condenses on the lid, creating water that eventually drips back into the dish. This constant moisture prevents soups and sauces from thickening properly. By slightly propping the lid open—using something like chopsticks—you allow the steam to escape, which helps reduce excess moisture and achieve the desired thickness for your sauce, soup, or stew.

Tips for making soup or sauce in a slow cooker

If you intend to let the soup or sauce simmer throughout the day, it's advisable to keep the heat on low. The edges of the slow cooker can become quite hot on high heat, and you want to avoid the risk of burning the outer edges of your soup or sauce.

When preparing a hearty soup (such as slow cooker split pea soup) that includes various ingredients like onions, carrots, or meat, feel free to add them to the slow cooker right from the beginning, as they are sturdy enough to hold their shape. However, for more delicate ingredients, such as small vegetables like peas or corn, it's best to add them toward the end of the cooking process to prevent them from becoming overly mushy after several hours.

If you're making a sauce and plan to use cream to thicken it or alter its texture, add the cream at the end as well. Incorporating the cream at the end, along with briefly opening the slow cooker lid, will result in a deliciously thickened soup. No matter what you're cooking, the evaporation process remains the same, so slightly prop the lid open to help thicken your dish.