How we tested
Since the rise of factory-produced butter in the early 20th century, the vast majority of butter sold in this country has been the sweet-cream kind. This style is quickly and cheaply mass-produced by churning cream that has undergone little or no storage. At the same time, old-fashioned cultured butter—made more slowly, with cream that’s allowed to ripen for a few days to develop flavor and then inoculated with bacterial cultures before churning—has typically been an imported, hard-to-find luxury. But these days, the tables seem to be turning: Not only is cultured (also known as European-style) butter increasingly available, but many supermarket shelves now hold more brands of this pricier condiment than brands of the sweet-cream stuff. Fans of cultured butter rave about its fuller, more complex taste.
Given that we go through upwards of 25 pounds of butter per week in the test kitchen, we wondered if we should stick with our longtime favorite supermarket butter—or fork out as much as $12 per pound for a premium butter? With that question in mind, we bought out the butter aisle and returned to the test kitchen with 10 unsalted butters: six cultured and four sweet cream. Our main criterion was simple: We wanted the best-tasting butter we could find for eating straight up on things like toast, pancakes, and corn on the cob. But since many of the cultured butters also contain more fat than the sweet-cream varieties do, we wanted to see how that extra richness affected flavor and texture in baking; for that test, we baked French butter cookies. The results, we decided, would have to be pretty spectacular for us to shell out nearly double or triple what we pay for regular butter.
We let the samples soften and then spread them on plain crackers—a blank canvas that could expose their nuanced flavors. When we tallied up the results of this plain tasting, we found that there was something to all the cultured-butter hype: These European-style products took two of the four top spots. Several of the cultured samples inspired high praise for dairy flavor that was “deep,” “rich,” and even “grassy” and “mineral-y,” with a “long and complex finish” that stood apart from the cleaner, more straightforward flavor of the sweet-cream butters. We also found that the higher fat of cultured butters (about 83 to 86 percent butterfat compared with around 81 to 83 percent in the sweet-cream style) lent them a luscious, mouth-coating richness. Our top pick, called European-style, was not actually cultured, but its butterfat, at 83 percent, was as high as some of the cultured butters.
That said, the cultured butters weren’t preferred across the board in the plain tasting. Though none were unacceptable, a few did suffer distinct off-flavors that made them less pleasant as spreads. These flavors ranged from strong hints of fake-butter popcorn to suggestions of cheap Chardonnay. But that was only part of the story. Our two top favorites were both sweet-cream butter; in first place, one of the richest butters in the lineup, and in second place, our longtime favorite. Both outshone the other two sweet-cream butters—and several of the cultured samples—by a considerable margin. (The two other sweet-cream butters landed at or near the bottom of the heap.) So why doesn’t culturing always result in better flavor?
For an answer, we contacted Robert Bradley, a professor emeritus of food science and an expert on butter flavor and texture analysis at the University of Wisconsin. He suggested that the artificial movie-popcorn flavor we detected in some cultured brands was most likely linked to the type and amount of starter cultures added to the cream—in particular, a naturally occurring volatile compound called diacetyl that’s responsible for buttery, slightly tangy flavor and yellow color. (Diacetyl is used in margarine to imitate the flavor of butter, and a few California Chardonnays, known as “butter bombs,” actually encourage its growth in fermentation.) Ideally, Bradley explained, manufacturers will hit on just the right mix of cultures to develop some acidity, some diacetyl flavor, and a good, well-rounded background. The manufacturer of our longtime favorite butter nailed the formula, nicely balancing sweet, fresh-cream flavor with complex tang. Other brands proved that getting the bacteria cocktail just right is tricky—and imperfections can be glaringly clear, particularly when you’re eating butter straight up on crackers or bread.
And then there were the cookies. While we found that most of the cultured butters’ artificial, margarine-like flavors burned off in the oven, so did some of their appealing nuances. Furthermore, some of the cookies made with the highest-fat cultured butter failed to spread as much as they should, baking up firm and dense. We did a little research and discovered that butters with more fat soften at higher temperatures than those with less fat. In cookie dough, this can mean that the starch and protein set before the butter has time to fully soften and spread, so the cookies bake up higher and more dense.
That said, a few of the cultured butters distinguished themselves in cookies that were both supercrisp and wonderfully buttery. But here again, most couldn’t top our favorite ordinary supermarket sweet-cream butter, which produced cookies that boasted “fresh-cream,” “clean dairy flavor” and nice sandy texture. So what was it about this supermarket butter that allowed it to repeatedly perform so well?
It’s a Wrap
According to Bradley, the answer may be as simple as the brand’s wrapping. Butter’s high proportion of fat makes its flavor fragile and highly susceptible to picking up odors from anything that’s stored near it. And the longer it’s exposed to other odors, the more its own flavor will be affected. (The U.S. Department of Agriculture maintains strict sanitation and cream-quality standards for butter production, but no such standards exist for how long and under what conditions butter may be kept in frozen storage or at the market.)
Bradley explained that the waxed parchment that some manufacturers use to cover their product does nothing to block out foreign flavors. Sure enough, in our tasting, three out of the four parchment-wrapped samples elicited complaints about off- or stale-tasting refrigerator flavors. Only the fourth butter, our previous favorite, did not. Bradley was not surprised. This brand, he explained, treats its parchment wrapper with a patented coating called FlavorProtect that helps lock in the butter’s clean flavor and keep intruding odors out. In fact, its wrapper was just as effective as the foil wrappers that covered six other butters we tasted—and more protective than one block’s foil wrapper, which, to the detriment of that butter’s flavor, arrived slightly gapped in a few spots. (We sealed all of our samples in zipper-lock bags as soon as they arrived, but that couldn’t reverse the damage done to any butter whose flavor was already spoiled.)
Cream of the Crop
Our top choice offered everything we look for in good butter: flavor that’s at once sweet and creamy, plus enough butterfat (almost 83 percent) to make it decadent and glossy but not so rich that it renders baked goods dense and greasy. The only part that’s hard to swallow is the butter’s price tag. At $10 per pound, it’s a splurge and a condiment-only purchase for most of us—especially considering the fact that our second-place finisher is less than half the price ($4.79 per pound).