America's Test Kitchen LogoCook's Country LogoCook's Illustrated Logo

Conventional vs. "Real" Buttermilk

Products labeled “real” buttermilk are popping up at supermarkets. Is it different from the buttermilk that you usually see?

In the old days, buttermilk was simply the liquid left behind after cream was churned into butter. As unpasteurized cream sat “ripening” for a few days before churning, naturally occurring bacteria caused it to ferment by converting milk sugars into lactic acid, which made the resulting buttermilk mildly sour and slightly thickened.

But since virtually all milk and cream is now pasteurized at high temperatures, a process that kills off those bacteria, most buttermilk sold today is cultured buttermilk, made by reintroducing lactic-acid bacteria to pasteurized skim or low-fat milk. Often, it’s also reinforced with salt and thickeners like carrageenan and starch. Few commercial manufacturers today sell buttermilk that’s truly a byproduct of the butter-making process, and the only one we found locally was Kate’s Real Buttermilk. (Even Kate’s, though, is made by adding bacterial cultures, since its butter is churned from pasteurized cream.)

We tested Garelick Farms Cultured Lowfat Butter Milk against Kate’s. Though Garelick Farms, unlike Kate’s, contains additives, we noticed little difference in flavor or consistency when we tasted the two straight. (Some tasters noted that Kate’s was a bit “brighter.”) We then used both in our buttermilk drop biscuits and in creamy coleslaw. Again, most tasters found them identical. Since conventional buttermilk is easier to find and costs about 65 cents less per quart, we’re happy to continue using it for baking and cooking.

This is a members' feature.