Why You Should Always Keep Buttermilk in the Refrigerator
You can tell a lot about a person by peeking into their refrigerator. One thing you'll always find in mine is a carton of buttermilk. It's a staple in my kitchen, and not just for pancakes. My son asked me the other day if buttermilk was a combination of butter and milk, which is apparently a common misconception. As much as I rely on the stuff, however, even I wasn't quite sure what buttermilk is, so I did some digging into the science behind it. It turns out that traditional buttermilk (made before pasteurization, that is) was a byproduct of the butter-making process. The liquid that remained after churning cream into butter came to be known as buttermilk. Since the fat in the cream went into the butter, this liquid was naturally fat-free, though it retained the naturally occurring sugars (what we know as lactose) in the cream. When exposed to bacteria in the air (again, this was before pasteurization), the sugars fermented into lactic acid, which in turn caused the liquid to thicken and develop a slightly sour, tangy taste. (Buttermilk was also known as sour milk, and if you look in some old cookbooks, you may find it listed as such.)
These days, buttermilk is no longer a byproduct. What we buy in the grocery store is cultured buttermilk, produced by combining pasteurized non- or low-fat milk with bacterial cultures, to produce the necessary lactic acid. A friend who grew up on a farm in Wisconsin once told me that her parents drink a glass of buttermilk every morning for their health. It's a probiotic food, believed to aid digestion and promote gut health, among other benefits. It provides a good amount of calcium and vitamin D without all the fat of regular milk.
Delicious Ways to Use Buttermilk
Try swapping buttermilk in for higher fat sour cream, as in this tasty Green Goddess Dip (my go-to lunchtime or pre-dinner snack). Likewise, you can use it in mashed potatoes or potato salads to cut out some of the heavy cream or mayonnaise. Buttermilk is also a great way to cool off in the heat (it's been used this way in India for ages). I try to keep a container of this simple, no-cook, blended soup on hand when the temperature spikes. It's much quicker to make than gazpacho, and easier to digest. Thanks to the lactic acid, buttermilk also makes an excellent marinade. For the most tender chicken or fish, try this all-purpose marinade. Or, give Martha's favorite fried chicken recipe a go; an overnight bath in buttermilk makes all the difference:
Baking with Buttermilk
Buttermilk really shines in baking recipes. At breakfast, I find buttermilk biscuits and scones to have much more character than those made with milk or cream. (When I don't feel like baking first thing in the morning, I often pull out the blender for a buttermilk smoothie. For dessert, I love to use buttermilk in custardy pies, tender cakes, and cupcakes as well as in sorbets and sherbets that taste much lighter yet just as luscious as ice cream. My absolute favorite (and most frequent) use of buttermilk is for Irish breads. My kids love brown bread pair with jam and salted Irish butter for breakfast and with smoked salmon and scrambled eggs for dinner. I prefer non-sweet soda breads, without currants or caraway seeds.
It's Practical, Too
Beyond all the deliciousness and the health benefits, buttermilk keeps longer than regular milk, too. The lactic acid makes it less prone to spoilage than other dairy products. I find that commercial buttermilk doesn't go bad even a week or two after opening (though the flavor does diminish a bit). I've heard that you can freeze buttermilk if you are worried about spoilage, but that's not a problem I've ever faced.
Finally, if you're still not convinced that you need to keep buttermilk on hand at all times, you can make an easy version of your own by mixing a cup of regular milk with lemon juice or white vinegar (both acidic ingredients), and then letting it sit for about 10 minutes. This is technically known as clabbered milk. Or, add 1½ teaspoons cream of tartar (another acid) to a cup of regular milk. I've tried all of these DIY versions, and they work in a pinch, but I still prefer the flavor and texture of the commercial kind. Its versatility means you'll never run out of reasons to put it to delicious use.