Buttermilk

Traditionally the thin, tangy liquid left after churning butter. What you buy today is cultured low-fat milk, thick and sour from added bacteria. Its acidity reacts with baking soda for lift, tenderizes gluten for a soft crumb, and adds a gentle tang to biscuits, pancakes, soda bread, and sandwich loaves.

By Henry Hunter · Updated October 1, 2026

Henry's notes from the bench

• Out of buttermilk? Stir 1 tablespoon (15 ml) of lemon juice or white vinegar into 1 cup (240 ml) of milk and let it sit 5 to 10 minutes. It won't be as thick, but it'll do the job.