1. Add milk
One of the easiest ways to “put out the fire” for over-salted soup is to add milk. Add a little yogurt, cream, milk, or sour cream to the soup. The neutral flavor of milk serves to dilute and also add creaminess to the soup. Coconut broth, butter, or a little olive oil can have a similar effect on vegetable soup.
2. Add lemon, vinegar
It may seem counterintuitive, but adding a small amount of acid from vinegar, lemon, lime, or tomatoes to the soup can eliminate some of the saltiness by distracting your taste buds. Try squeezing lemon juice or apple cider vinegar. And if you’re cooking a pureed dish, adding a little tomato can help reduce the saltiness.
3. Use potatoes
To reduce the saltiness of soup due to accidentally adding too much salt, add a peeled raw potato to the cooking pot. Potatoes, rich in starch, will absorb the liquid and some of the excess salt. All you need to do is remove the potato after it has been added to the soup before it is fully cooked. (Cutting the potato into pieces will maximize the surface area and speed up this process, but it also increases the chance of the potato absorbing the saltiness).
4. Dilute the soup
If you have added too much salt to the soup and still have remaining ingredients in the recipe, you can reduce the salt concentration by adding more ingredients to the soup. Additionally, you can reduce the saltiness by adding boiling water or boiled vegetable water to lighten the soup. If adding water makes the soup too watery, you can add 1 teaspoon of cornstarch to thicken it.