As Joy says on her site, buttermilk is a slightly thicker, sour milk. The sourness of buttermilk comes from lactic acids in the milk. It’s an important part of baking – the acidic milk combined with baking soda in a recipe lifts and lightens whatever you’re baking. When the buttermilk and baking soda are combined, the baking soda releases carbon dioxide that (when heated), releases tiny bubbles that expand and lift and lighten whatever you’re baking. 🙂
It’s rare that I buy buttermilk these days. I usually just use the milk I have on-hand to make my own. So, I figured I’d share how I’m doing it so you don’t think you’re always going to have to run to the grocery store just to get buttermilk for a recipe. 😉 This is usually the link I click on every single time I google “buttermilk substitute.”
What you need:
- Milk (just under one cup)
- 1 Tablespoon white vinegar or lemon juice
What to do:
- Place a Tablespoon of white vinegar or lemon juice in a liquid measuring cup.
- Add enough milk to bring the liquid up to the one-cup line.
- Let stand for five minute. Then, use as much as your recipe calls for.