Buttermilk is a key ingredient when it comes to making the perfect cakes, muffins, and other baked goods
There are two different kinds of buttermilk. Original buttermilk is the liquid that is left after butter-making. Cultured buttermilk is milk that has been cultured by bacteria. Cultured buttermilk is desirable to use in baking.
But why?
Buttermilk tenderizes baked goods by adding extra leavening power. When it is produced, the lactose in the milk is converted to lactic acid. When this acid is combined with baking soda, a chemical reaction happens as the acid neutralizes. This reaction releases carbon dioxide, resulting in a more tender cake than you would get by using water or regular milk.
Light Buttermilk Or Old Fashioned?
The amount of milk fat that is in the buttermilk you use is a personal preference. I personally prefer using buttermilk containing 3.25% milk fat (old fashioned buttermilk). I've found that it produces a slightly more dense cake that has more depth of flavor. If you are looking for a lighter cake, 1% milk fat buttermilk (light buttermilk) may be a better choice.
Substitutes for Buttermilk
Unless you are an avid baker, you might not always have cultured buttermilk on hand. Luckily, it is quite easy to substitue with ingredients you probably already have on hand. 1 cup buttermilk = 1 cup plain yogurt
1 cup buttermilk = 1 Tbsp lemon juice or white vinegar and then milk to equal 1 cup. Let set for at least 10 minutes.
1 cup buttermilk = 1/2 cup sour cream + 1/2 cup or milk