Traditionally, homemade buttermilk was the slightly sour liquid that remained after butter was churned and separated from milk. Today, most commercial buttermilk is actually "cultured buttermilk," meaning it is manufactured by adding lactic acid bacteria to non-fat or low-fat milk. It is slightly thicker in texture than regular milk, but not as heavy as cream. With a flavor similar to yogurt, it is commonly used as an ingredient to enhance baked goods or make crème fraîche.
Early American settlers found many ways to use the liquid leftover from their home-churned butter. Most notably, they discovered buttermilk gave their breads, cakes and biscuits a light, fluffy texture that other liquids could not replicate. Pioneer women also used buttermilk as a facial wash for soft, creamy complexions. And according to folklore, many thought drinking buttermilk could protect them from poison ivy or even cure a hangover.
Always look for the carton with the latest expiration date, as you would for any dairy product. Buttermilk is also available in a shelf-stable dehydrated powder that is great to have on-hand for baking.
Keep buttermilk refrigerated and don't let it sit out on the counter for long periods of time. It will last up to two weeks, but once opened, should be used within one week for drinking purposes. It will still be fine for baking, even a few days after the expiration date. Buttermilk separates as it sits, so shake well before using.
Buttermilk can also be frozen for up to three months. Thaw in the refrigerator and mix well before adding to recipes.
Powdered buttermilk lasts indefinitely on the shelf unopened. Once opened, refrigerate for up to one year.
Buttermilk is excellent in baked goods as it promotes browning and leavening while improving texture. Acidic properties also make it a great base for salad dressing or a marinade for meat, poultry and fish. Next time you make fried chicken, dip your pieces in buttermilk before coating for moist, flavorful results.
Health-conscious eaters might try buttermilk as a refreshing beverage or alternative topping to butter or sour cream. Buttermilk is lower in calories and fat and it's also a good source of potassium, vitamin B-12, calcium, riboflavin and phosphorous. Why not give it a try in your next batch of mashed potatoes?
When buttermilk is not available, try these easy equivalents: