Select an air fryer-safe container for your soup. This could be a glass, ceramic, or any other oven-safe dish that fits comfortably in the air fryer basket. Avoid using plastic or any material that can't withstand high heat.
Pour your leftover soup into the chosen container. If the soup has thickened in the fridge, you can add a little broth or water to bring it back to your desired consistency.
To prevent the soup from drying out and to ensure even heating, cover the container. You can use aluminum foil or an air fryer-safe lid. This step is crucial as it helps to keep the moisture in and heat the soup evenly.
Some air fryer models work best when preheated. Set your air fryer to around 300°F (150°C) and let it warm up for a few minutes if your model recommends preheating.
Carefully place the container with the soup in the air fryer basket. Be sure it's stable and not at risk of tipping over.
Heat the soup at a moderate temperature, around 300°F (150°C). The time will depend on the amount and type of soup. Start with 5-7 minutes for a single serving and adjust as needed. It's better to heat gradually than to overheat the soup.
Halfway through the reheating time, carefully open the air fryer, remove the cover, and stir the soup to ensure even heating. This is also a good time to check the temperature. If it needs more time, continue heating in short intervals, checking every few minutes.
Once the soup is heated to your satisfaction, carefully remove the container from the air fryer using oven mitts. Stir the soup well before serving.