How to Make Buttermilk
So, what is buttermilk? Traditionally, buttermilk was the fermented liquid left over after churning cream into butter. These days, store-bought buttermilk is typically made from milk with added lactic bacteria, which produce lactic acid.
Contrary to what its name and thickened texture suggest, buttermilk is not buttery and is relatively low in fat. Store-bought options are usually about on par with whole milk, though reduced-fat options exist.
Why do we use buttermilk instead of plain milk? Tangy flavor aside, the acid present in buttermilk helps counteract baking soda, which is basic. Baking soda on its own is quite bitter—it needs both acidity and liquid to taste and function properly.
Buttermilk acts similarly to sour cream or yogurt, which are thicker cultured dairy products. Since buttermilk is thinner, I typically use about two-thirds cup buttermilk in place of one cup sour cream or yogurt.
Today, we’re talking about acidified buttermilk, or milk with added acid (vinegar or lemon juice) so it acts as buttermilk. This is the perfect substitute for your baking projects when you don’t have buttermilk on hand.
I love use this trick because it saves me from buying buttermilk, since I never seem to use up a full bottle in time! This method is also convenient if you follow a dairy-free or vegan diet, because you can make buttermilk with any type of milk.
Basic ratio: 1 tablespoon vinegar or lemon juice + 1 cup milk of choice = 1 cup buttermilk
To make buttermilk, simply measure the vinegar or lemon juice into a liquid measuring cup. Fill the cup with milk up to the 1-cup line (so yes, you’ll be using just a tiny bit less than 1 full cup milk). Stir to combine, and let the mixture rest for at least 5 to 10 minutes before using.
The final texture should appear somewhat separated at the top, with some light curdling. Even if you don’t see a significant change in appearance, the acidity is present and your buttermilk should work as designed.
Following this ratio, you can make exactly as much buttermilk as you need. Keep in mind that one tablespoon is the equivalent of three teaspoons. Here are some alternate yields for your convenience:¼ cup buttermilk:
- ¾ teaspoon vinegar or lemon juice + ¼ cup milk of choice
- ⅓ c cup buttermilk: 1 teaspoon vinegar or lemon juice + ⅓ c cup milk of choice
- ½ cup buttermilk: 1 ½ teaspoons vinegar or lemon juice + ½ cup milk of choice
- ⅔ cup buttermilk: 2 teaspoons vinegar or lemon juice + ⅔ cup milk of choice
- ¾ cup buttermilk: scant 2 ½ teaspoons vinegar or lemon juice + ¾ cup milk of choice
