What it is: Traditionally the liquid left after churning butter, modern buttermilk is cultured for tang and thickness, perfect for baking and cooking. Why it works: Its acidity reacts with baking soda ...

Why it works: Buttermilk’s acidity reacts with baking soda to create air bubbles, giving baked goods a lighter texture while adding tang and moisture. DIY buttermilk: Mix milk with lemon juice or ...