⭐ Buttermilk (Best Fat-Free Option)
1/2 cup buttermilk per 1/4 cup sour cream Quick tip: Use less buttermilk due to its thinner consistency; add at the end of cooking off heat.
Buttermilk provides the acidity and tanginess similar to sour cream but is much thinner, which can dilute the soup if used in equal amounts. It works well to add brightness and a slight creaminess when used sparingly.
To prevent separation, add buttermilk after removing the soup from heat and stir gently. Avoid boiling after addition.
The soup will be lighter and tangier but less creamy, with a thinner mouthfeel compared to sour cream.