Greek Yogurt (Best Option)
1:1 (1 tablespoon Greek yogurt per 1 tablespoon sour cream)Greek yogurt works well because it contains live cultures that provide the tanginess similar to sour cream, and its thick consistency mimics the creamy mouthfeel. The protein content also helps maintain a rich texture in oatmeal.
For best results, use plain, unsweetened Greek yogurt to avoid adding unwanted sweetness or flavors. Stir it in after cooking to preserve its texture and tang.
Compared to sour cream, Greek yogurt may be slightly tangier and less fatty, which can make the oatmeal taste fresher and lighter but still creamy and satisfying.