Rice Vinegar with Water (Best Option)
1 tablespoon rice vinegar + 3 tablespoons water per 1/4 cup buttermilkRice vinegar is mildly acidic and provides the tanginess needed to mimic buttermilk's tenderizing effect on proteins in stir-fry dishes. Diluting it with water prevents overpowering acidity and excess moisture that could steam rather than sear ingredients.
For best results, add the mixture towards the end of cooking to maintain acidity and avoid overcooking the vinegar. Monitor the dish to ensure the acidity complements rather than dominates the flavors.
Compared to buttermilk, this substitute maintains the bright, slightly tangy profile essential for stir-fry marinades or sauces without introducing dairy, thus preserving the ideal texture and cooking dynamics.