⭐ Buttermilk (Best Fat-Free Option)
3/4 cup buttermilk + 1/4 cup whole milk per 1 cup sour cream Quick tip: Buttermilk adds acidity and moisture but thins the dough slightly, so milk balances hydration.
Buttermilk is acidic and contains moisture that supports yeast activity and gluten structure, similar to sour cream. However, it is more liquid, so adding whole milk compensates for the moisture difference to maintain dough consistency.
Mix buttermilk and milk well before adding to the dough. Monitor dough hydration and adjust flour slightly if needed to prevent a sticky dough.
The bread will have a mild tang and a slightly lighter crumb, with good rise and texture close to the original.