Milk + Lemon Juice (Best Option)
1 cup milk + 1 tablespoon lemon juice (let sit 5 minutes)Milk combined with lemon juice creates a mild acidic environment that mimics buttermilkās tanginess and slightly thick texture. The acid causes the milk proteins to coagulate slightly, giving a texture closer to buttermilk.
For best results, use whole or 2% milk and let the mixture sit for about 5 minutes before adding to the soup to ensure proper acidity development. Stir gently into the soup near the end of cooking to avoid curdling.
This substitute maintains the soupās balance of acidity and creaminess, resulting in a flavor profile and mouthfeel very close to that achieved with buttermilk.