I RECENTLY silenced a room full of experts on diet and health by asking if it was time to rethink butter. The scientists at the meeting, which was organized by the Harvard School of Public Health and Oldways, a kind of nutrition brain trust, had seemed to be on the verge of giving the nod to butter. They were saying that synthesized "trans-fat," which is in stick margarine, is no better for the heart than saturated fat, the main kind in butter. They were saying that the high levels of fat in our current diets need not invariably lead to bad health and obesity -- so long as we exercise, eat less food in general, and make sure the fats we eat are the right kinds. Why not butter? I wondered. It's genuine and unadulterated, and most people love it. I was never a butter-lover myself (except when it came to cookies). Given the dull sameness of most brands, it hardly seemed worth the calories, let alone the health risks, to spread butter on bread. In the past year or two, though, I have tasted butter with far more flavor than I thought possible. The analogy to olive oil seems obvious. When it became clear that mono-unsaturated fats, the main kind in olive oil (especially extra-virgin oil), were the least risky for the heart and possibly of help in preventing cancer, gourmet markets and restaurants started selling and using just-harvested oils. These showed the peppery, fresh flavors that olive oil could have. Soon there was a competition to see who could offer the fanciest bottle of oil just out of the press. Recently the same markets have begun stocking butters with beautiful silver and gold labels. These show what full, tangy, rounded flavor butter can have.
The experts' resounding silence made clear that they were not about to change their stance: mono-unsaturated fat is still the fat to have if you're having fat. I was undeterred. During a fruit break several researchers and nutrition activists admitted in private conversation to being impassioned connoisseurs of chocolate and ice cream. Their excuse was that the fats that cause real problems are rarely the ones people deliberately add to what they eat, or even think much about. That is, you're less likely to ruin your health with the expensive imported Normandy butter you spread on a fresh baguette than with the melted "real butter" doused on movie-theater popcorn, let alone the oil in fast-food french fries. (And don't think that the new fake-fat potato chips will help your health: the long-term effects of losses of fat-soluble nutrients, which consuming Olestra can cause, are unknown and potentially troubling.)
I did not win the scientists' blessing for butter. But they did wholeheartedly endorse buying and eating the freshest food possible, whatever the food. If I still had to restrict my allotment, all the more reason to learn why some kinds of butter taste so much better than others -- that is, when you pay attention to the taste.
MOST butter has little to no flavor, and cooks and bakers like it that way. They prize its ability to be a sounding board, to enhance and magnify other flavors while adding only a slight creamy taste of its own. The qualities they look for are freshness and neutrality. Bakers want a firm plasticity, which gives their cakes and especially pastries superior texture. In recent years the vogue has been for higher-fat butters: bakers who can afford it buy Plugrá, whose name comes from the French for "more fat," or Echiré. American standards call for butter to contain a minimum of 80 percent butterfat. Even if one or two percent more fat sounds like a small difference, premium butters "perform" better in sauté pans and mixing bowls, and on the palate they can have a more mouth-coating, satiny feel.
But my search was for flavor, not performance, and flavor comes from cream and how it is treated -- matters with which, surprisingly, most cooks and bakers are little concerned. Plugrá and its imitators, and also Land O Lakes, still the baker's gold standard, are sweet-cream butters. The name has a nice sound, but sweet-cream butters are bland at best. The revelation of my research was that butter can actually have a distinct -- and desirable -- flavor of its own. That flavor comes from allowing the cream it is made from to sour ever so slightly.
This intentional fermentation is quite different from what causes the flavors cooks object to. It's very hard to taste any kind of butter at its best, because of the numerous possible storage mishaps between the dairy and the kitchen. Butter works as a sounding board not just for mushrooms and shallots in the sauté pan but also for onion and broccoli in the refrigerator. Furthermore, butter-makers often add heavy doses of salt, partly to compensate for blandness and chiefly to add shelf life. During the months before the official sell-by date, however, butter can begin to turn rancid, especially if storage conditions are less than ideal. Most people's experience of butter flavor, then, is salt, slight rancidity, and whatever else is in the refrigerator.
You can make sweet-cream butter at home that will avoid these problems, and if you have ever let your attention wander while whipping cream, you have probably made butter already. It takes only seconds for cream to turn from a suspension of fat globules in water to a suspension of water in fat. Perfectly fresh butter gives you the chance to taste what sweet-cream butter should be, without the overwhelming salt of salted butter or the off-flavors of so much store-bought butter.
Even pristine homemade butter, though, is unlikely to lead to the kind of conversion I underwent. The chief reason is that it is almost impossible to buy cream -- the one thing you need to make butter -- that has any taste. Commercial dairies heat cream to a very high temperature, or "ultra-heat-treat" it, so that it will last for weeks without souring. This is calamitous for flavor. The many strains of good bacteria that can give interest and depth are wiped out in the process, along with the handful of bad bacteria that cause spoilage or disease. This is why artisans concerned about the taste of their butter inoculate the cream with specially selected strains of bacteria.
Not all flavor need be wiped out when milk or cream is pasteurized. Measures short of induced souring can greatly improve the taste of milk or cream. The first rule is not to blast it to blandness. Ultra-heat treatment is just the worst -- if easy and ubiquitous -- choice for cream. Straus Family Creamery, in the gorgeous hills of Marin County, chooses not to introduce bacteria into the organically produced cream it uses, pasteurizing the cream at a lower-than-usual temperature to make fresh-tasting sweet-cream butter. It immediately freezes and ships the butter to several western states (and anywhere customers are willing to pay the freight; you can order it on the Web at strausmilk.com).
Despite what propaganda for the "Mediterranean diet" would lead you to believe, countries along that sea still cook with plenty of butter. On Sardinia, for example, butter is nearly as important a cooking medium as lard and olive oil. The island's top-selling butter is made with sweet cream by Latte Arborea, a dairy built in the 1920s on a formerly malarial Sardinian swamp. The Fascist regime named the built-from-scratch town Mussolinia; now it is the pastoral Arborea. When I toured the dairy not long ago, the sophisticated woman accompanying me told our guide that as far as she was concerned, the Arborea butter she knew from the supermarket might as well be wax. Then she tasted butter fresh out of the churn, before it was even packaged. Her eyes widened at its unexpectedly nutty, pure flavor, and her face reddened at her frankness seconds before.