How to Make Your Own Buttermilk at Home

If you’ve ever been halfway through a recipe—say, whipping up a batch of our fluffy Red Velvet cupcakes—and realised it calls for buttermilk, you’re not alone. It’s one of those ingredients we don’t always keep stocked in the fridge and often isn't worth buying a whole carton just for one recipe. But here’s the good news: making homemade buttermilk is super easy, and it only takes a couple of minutes. You most likely have all of the ingredients in your fridge and pantry already!

At Brooki Bakehouse we use buttermilk in some of our cupcake recipes so we often need to have it on hand in bulk. But at home, you're likely to only need a small amount. So, let’s break down exactly how to make your own buttermilk substitute whenever you need it.

What is Buttermilk, Anyway?

Buttermilk isn’t actually buttery at all. Traditionally, it was the tangy liquid left behind after churning cream into butter. Today, the buttermilk you find in stores is usually cultured milk—slightly thick, with a signature tang that makes baked goods extra tender and flavourful. It makes for a delicious addition to cakes and cupcakes, particularly vanilla and red velvet.

In recipes, buttermilk:

• Reacts with baking soda to help your cakes rise beautifully

• Adds a subtle tang that balances sweetness

• Keeps bakes soft, moist, and never dry

How to Make Buttermilk (2 Easy Methods)

Here’s the quick fix to make your own buttermilk recipe at home in just a few simple steps. Remember: room temperature ingredients always!

Method 1: Lemon Juice + Milk

• 1 cup (240ml) whole milk

• 1 tablespoon fresh lemon juice

Method 2: Vinegar + Milk

• 1 cup (240ml) whole milk

• 1 tablespoon white vinegar or apple cider vinegar

Simply stir the milk and acid together, let it sit for 5–10 minutes until slightly thickened and curdled, and you’ve got a perfect buttermilk substitute ready to use. 

Brooki’s Pro Tips ✨

• Whole milk works best in baking, for a full body flavour.

• Always let the mixture rest before adding it to your recipe—this activates the magic.

• Scale up the ratios if your recipe calls for more buttermilk.

• Always use room temperature milk so the thickness can develop fully. 

Why You’ll Love This Hack

Making your own buttermilk means you’ll never have to make an emergency grocery run again. Plus, it ensures your cakes, cookies, and brownies stay soft, tender, and bakery-worthy—just the way we like them at Brooki Bakehouse.

So next time your recipe calls for buttermilk, remember: you’ve already got the secret in your fridge.