⭐ Milk + Lemon Juice (Best Nut-Free Option)
1 cup milk + 1 tablespoon lemon juice (let sit 5 minutes)Adding lemon juice to milk creates a mild acidulated milk that mimics the acidity and slight curdling effect of buttermilk. This acidity helps tenderize the starches in the potatoes and balances the richness of the meat and butter in the pie.
For best results, use whole milk for creaminess and allow the mixture to sit for at least 5 minutes to curdle slightly before adding to the potatoes. Avoid using skim milk as it lacks fat, which affects mouthfeel.
This substitute preserves the traditional light and fluffy texture of the mashed potato topping while adding a subtle tang that brightens the overall dish without overpowering it.