Here’s the nerdy part: milk is mostly water with a bit of fat and protein. Buttermilk has lactic acid—that’s what makes it tangy. When you bake with it, that acid teams up with baking soda to create carbon dioxide. Hello, rise!
Using Buttermilk Instead Of Milk In Scones at Ruby Hereford blog
So if your recipe calls for baking powder (which already has acid), swapping in buttermilk might make things too acidic. You’ll need to add a pinch of baking soda to balance it out. It’s like a chemistry party, and you’re the host.
Pro tip: if you’re subbing buttermilk for milk in a savory dish like mashed potatoes, just add a splash of water to thin it out. Or better yet, embrace the tang—it’s delicious with roasted garlic.
The “Oops, I Only Have Buttermilk” Fix
Let’s say you’re committed to that pancake recipe but only have buttermilk. Here’s your game plan: reduce the other liquids in the recipe slightly, since buttermilk is thicker. Or add a tablespoon of milk or water per cup of buttermilk to thin it.
Also, if your recipe calls for a lot of sugar, the tang will be muted. Sweet batters (like vanilla cake) hide the sourness beautifully. Savory recipes? The tang can actually brighten them, like in cornbread or soda bread.
And please, for the love of breakfast, don’t try to microwave buttermilk into a hot drink. I did that once. It looked like cottage cheese soup. Learn from my mistakes.
