New York Times readers learned today what Slate readers have known for months: that the buttermilk you buy at the store is not actually the byproduct of butter. The dining section’s Julia Moskin profiles a few folks who are trying to bring back a “dairy product that has almost disappeared from American tables: real buttermilk, the creamy liquid that remains in the churn after the butter comes together.” Moskin describes this liquid (“what’s left of heavy cream once it has been churned”) as “naturally defatted milk, with microscopic traces of butter that leave a haunting, rich flavor and a creamy mouth feel.”
Unfortunately, this is a total oversimplification of the issue. As I discovered while researching my May article about the history of buttermilk, there is no such thing as “real buttermilk”—or, at least, there’s no one kind of “real buttermilk.” Historically, the word “buttermilk” has been applied both to regular milk that has turned sour (the approximate equivalent of today’s supermarket buttermilk) and to the liquid that remains in the churn after butter-making. And the latter—what Moskin calls “real buttermilk”—is hardly uniform. There is “sweet” buttermilk, which is made from uncultured milk, and then there is sour buttermilk, which is what you get when you churn sour milk (also known as cultured milk).
The texture and flavor of the buttermilk also depends heavily on the fat content of the dairy product you start out with. If you start with whole milk or light cream, you’ll get a thicker, creamier buttermilk; if you start with heavy cream—as I did when I tried making buttermilk at home—you’ll get a thin, watery liquid with only the slightest hint of butter flavor. As Anne Mendelson, the author of Milk: The Surprising Story of Milk Through the Ages, told me in an email:
In my opinion, buttermilk from sweet-cream butter is one of the world’s most boring substances. It’s not bad exactly, it’s just bland to a fare-thee-well. … When you churn thoroughly cultured whole milk (unhomogenized) or light cream, you get buttermilk both better-textured and better-tasting than anything from heavy cream, because it contains more of the original casein from the milk and has a certain appealing “cheesiness.”
Moskin is a great, highly knowledgeable reporter, and I understand why she wanted to simplify things for the sake of clarity in her article. But readers who think they’re going to get “a haunting, rich flavor and a creamy mouth feel” by churning uncultured heavy cream are in for a disappointment. (That disappointment will be mitigated slightly by taking a gander at the slide show accompanying Moskin’s piece—there’s nothing like the sight of an enormous trolley packed with butter to cheer you up.)