Milk

by Anne Mendelson

Why does melting butter so irreversibly change its basic consistency? The answer lies in the breaking up of fat globules in the churning process. Milk or cream is ordinarily chilled in preparation for churning. Chilling any liquid fat to a solid state causes it to form crystals. The enclosure of milkfat within membrane-surrounded globules adds another complication. As some of the globule contents become crystallized, the sharp crystal edges are in effect primed to start rupturing globule membranes even before churning, encouraging the formation of a continuous butter mass. But not entirely continuous; even after churning, some of the original fat globules remain intact, distributed throughout the body of the butter. The cold butter takes on a triple interior structure: part crystalline (which makes it brittle), part continuous (which makes it malleable), part globular. When it melts, this unique architecture is effaced a little at a time along with other changes including the escape of volatile components. Once rechilled, the butter hardens into coarser crystals large enough to be detected as a grainy “mouthfeel.”

  The ease with which butter absorbs the smells and tastes of other foods is yet another effect of membrane disruption. Components that were comparatively impervious to outside influences while they remained locked up in the inner or outer face of the globule membrane are now distributed through the butter. They include various unstable radicals, or unattached fragments of molecules, that are ready to react with whatever they come in contact with. It so happens that raw onions or other alliums, once cut, release their own arsenal of highly reactive volatile sulfurous radicals in search of attachment points on other substances. Put butter in contact with these “allicins” (in fact, nearly anything vigorously smelly), and you have something like the meeting of two desperately lonely people in a singles bar. All fats and oils tend to be affected by foreign aromas and flavors, but the unique composition of butter makes it the most susceptible of all.

  Today various foods seem to be the beneficiaries of a backlash against the more naive preachments of yesteryear, and butter is among them. The nutrition vigilantes who spent much of the 1980s and ’90s assuring us that various margarines were a far more healthful alternative have changed their tune following a spate of reports about the effects of trans fatty acids, a class of unsaturated fatty acids in which carbon atoms accept extra hydrogen atoms attached by peculiarly angled double bonds that make the resulting compounds look and behave more like saturated fats. (Small amounts of trans fatty acids occur naturally in milkfat, but they represent only a tiny fraction of the volume now pouring into the food supply from commercially manufactured fats.) To an extent, butter is getting cleared of a disrepute that it never should have incurred in the first place. But I should hate to see its fortunes tied only to the fluctuations of pop diet theory. In the end, the best reason to love it and welcome it (with a good dose of common sense) to our diets is that no other food even remotely mimics the unimaginable intricacies we experience in the ravishing effect of butter on bread, butter melted over a baked potato, butter in a frying pan, butter in a sauce or pastry.

  Here I should point out that the global diversity of butter is still pretty much a closed book in this country. As far as I know, strong-flavored versions produced by different kinds of handling with lengthy fermentation have not yet arrived here from places like Tibet, parts of the Arab world, or odd corners of Africa. It’s not only possible but probable that in a few years Americans will be readjusting their gastronomic compasses to take in kinds of butter far beyond Eurocentric models. Meanwhile, you can learn a lot about international preferences by searching for goats’-, sheep’s-, or even buffaloes’-milk butter and registering how greatly they differ from cows’-milk butter. (A few Greek groceries carry imported sheep’s-milk butter, and buffaloes’-milk butter from Italy shows up in a few specialty venues.)

  SALTED VERSUS UNSALTED BUTTER: SOME HISTORICAL PERSPECTIVE

  Unlike most milk and cream, plain butter as it reaches American consumers today in either salted or unsalted state probably is better made and better tasting than most of the counterparts produced on this continent before the twentieth century. I don’t mean butter inflated with gases or mixed with vegetable oils, but the ordinary mass-produced kind put up in quarter-pound sticks. It is a very particular, fairly modern artifact of northwestern European culinary culture, and its uniqueness is difficult to understand without some explanation of how butter reached different cuisines at different times. If you harbor strong prejudices about the superiority of either salted or unsalted butter, much of the reason lies in this same past.

  I have mentioned that the ancient Greeks, who didn’t raise milch animals for butter, puzzled their heads over the butter, or “cow cheese,” that they saw being scarfed down by barbarian cattle herders (this page). It’s highly unlikely that this curiosity resembled modern table butter, because it couldn’t possibly have been produced under the conditions that make butter waxy and delicate-tasting. Before modern chilling technology, a more important consideration would have been making the butter keep. Butter does last longer than the milk or cream that furnishes it, but that’s not very long. People therefore took to salting it, and sometimes burying it underground in pots or casks. To this day people in parts of the Middle East and North Africa bury butter long enough to reach some desired state of fermentation, and the custom of burying it in Irish peat bogs seems to be centuries if not millennia old.

  Given the perishablility of butter, it’s impossible to generalize about what it tasted like in ancient and perhaps early medieval Europe. Did people clarify it for longer keeping, or mix it with herbs for more complex flavors, as many of the world’s butter-eating peoples still do? Was it strong and almost cheesy-smelling like the North African smen? We may never know. But we do know that plenty of it was salted, probably to a degree that we would find harsh. And with repeated use the vessels it was churned in (animal skins in earliest times, later unglazed clay and wood) would have acquired penetrating smells and tastes that they then communicated to the butter.

  The butter of the Middle Ages was more a humble rural staple than a delicacy. The situation changed with the eighteenth-century rise of specialized modern dairying, when farmstead butter freshly churned for market became something of a luxury article for town-dwellers’ tables in England and northern Europe. The buttermaking scene in George Eliot’s novel Adam Bede, set in 1799, marvelously evokes what might be called the modern European butter esthetic: “it is so pure, so sweet-scented; it is turned off the mould with such a beautiful firm surface, like marble in a pale yellow light!”

  But fine, expensive butter made to exacting tastes was very far from most of the butter sold and eaten throughout the nineteenth century. From contemporary accounts, the usual article was likely to be ill-flavored or frankly rancid through poor handling. In countries that put up a lot of butter for mass commercial distribution (especially the United States and Ireland), it was routinely made with gross amounts of undissolved salt worked in before the butter was packed for keeping into large firkins—sometimes meant to last through a winter—that might be topped up with brine, resulting in a further salt crust on the surface. This did not stop poorly made butter from still being rancid or contaminated with foreign flavors.

  “America must have the credit of manufacturing and putting into market more bad butter than all that is made in the rest of the world together,” announced the domestic science writer Catharine Beecher and her sister Harriet Beecher Stowe in The American Woman’s Home (1869). By their reckoning, “about one pound of salt to every ten of butter” was a usual ratio—not surprising, with salt costing “five cents a pound and butter fifty.”

  The disdain for salted butter among many modern American food authorities is a remnant of this era. The Beecher sisters, who had tasted exquisite unsalted butter in France and England, saw the matter in better perspective. One could, they wrote, find at least some American butter “salted with care and delicacy, so that it might be a question whether even a fastidious Englishman might no
t prefer its golden solidity to the white, creamy freshness of his own.”

  The new dairying technology of the late nineteenth century resulted in butter of much more uniform and, on the whole, better quality, generally produced at centrifuge-equipped industrial creameries rather than on farms. There are advantages to doing some things on at least a modest industrial scale, and buttermaking is one of them. The fact is that being able to precisely measure fat content, buttermilk content, temperature, and other conditions, while using vessels and churning equipment a great deal cleaner than many earlier counterparts, raised the average quality of creamery butter well above any but the very finest farmstead article. (Eventually, batch churning was supplanted by more highly automated continuous-flow processes.) At the same time, revolutions in packaging, transportation, and home storage meant that nearly everyone could frequently buy butter put up in small amounts and keep it for short periods in an icebox or refrigerator. Before that, you either bought whole firkins meant to last you for months or went to the grocer’s for a pound or so dug out of a barrel, in either decent or horrible condition.

  By the time creameries proliferated, most American consumers had a taste for salted butter that persists to this day. The minority, at around the turn of the twentieth century, included culinary writers who fancied that unsalted butter was an elegant French preference, as well as a rising tide of Ashkenazic Jewish immigrants from the Pale of Settlement.

  Today salting is done less for preservation than because of taste preference, and salted butter is almost invariably made with amounts of smoothly incorporated salt that the Beechers would have thought quite delicate. Both salted and unsalted versions have a fine, waxy consistency and gratifying flavor that would have been far from routine 150 years ago. But the question of which kind is preferable still tends to be debated as if we were awash in butter coarsely oversalted to mask awful defects. I think the facts are much misunderstood.

  In the first place, good-tasting butter can be salted or unsalted. Setting aside the differences between butter churned from sweet or slightly soured cream (this page), the most important factors are first, cream without off flavors contributed by the animals’ feed or poor handling; second, meticulous control of temperature at every stage of churning and draining; and third, scrupulous working to remove nearly all the buttermilk while leaving just the tiny residue that will lend soul to the butter. Salt does not ruin well-made butter; it imparts something that some people care for and others don’t. Its aficionados can taste just as much complexity in salted butter as can the opposite party in unsalted.

  Though I was raised on salted butter, I eventually switched allegiances. Still, I’ve tasted enough good salted butter to disagree with knee-jerk responses about its invariable inferiority for spreading on bread or melting over vegetables. Other purposes are a different story. Unsalted butter is a must in any situation where the salt would tend to crystallize out of the whole and form a crust on the bottom of the pan—Beurre Noisette or Beurre Noir, any kind of clarified butter, or most dishes involving butter heated to a fairly high temperature for a long time. Pastry-makers say that salted butter often gives poorer results in baking because it tends to retain slightly more water. It also has disadvantages when you’re trying to pregauge the amount of salt needed for seasoning, especially since degrees of saltiness vary from brand to brand. If you cook with salted butter, it’s always a good idea to use much less salt than is called for in a recipe, then add more to taste if needed.

  Supermarket butter today may not be the ne plus ultra of wonderful butter, but whether salted or unsalted it’s usually pretty good. And even pretty good butter is a treasure beyond the power of industrial chemistry to imitate by playing games with either animal or vegetable fats.

  A SHOPPING AND HANDLING PRIMER

  Buying butter is not absolutely a guessing game, but you have to expect much inconsistency in labeling. The fine print may or may not clear things up. Some common terms are:

  • Sweet butter: Often incorrectly used as a synonym for unsalted butter. Properly speaking, it is butter made from sweet cream, as in the recipe on this page. Sweet butter can be salted or unsalted. The basic butter flavor is pure and simple.

  • Cultured or ripened butter: In the strictest sense, butter churned from cream that has been lightly soured by culturing with lactic-acid bacteria (see this page). Whether salted or unsalted, it has nuances of flavor and aroma not found in sweet butter. The genuine article is time-consuming and expensive to produce, and has largely been replaced by easier methods. Small amounts of lactic-acid cultures are often pumped into the butter after churning; this may not be easy to detect from the label, since “cultures,” “bacterial cultures,” or “cultured cream” can be listed among the ingredients of butter made by either method. A still more convenient shortcut is to buy distillates of the main flavoring substances that would have been developed by ripening and inject them into the churned butter. The most usual is diacetyl, a volatile compound with a bloomy fragrance. Lactic acid may also be directly added. The labels of butter so treated probably will have no clue except “natural flavoring,” which is accurate only in a pretty strained sense of “natural.” You know that you are getting true cultured butter if the label says that the cream was cultured before churning, but perhaps one maker out of dozens will vouchsafe this information.

  • European-style butter: A term with no fixed meaning, sometimes referring to cultured butter and sometimes to butter with a butterfat content higher than the usual 80 to 81 percent in American butter.

  • Creamery butter: A phrase left over from the late nineteenth century, when buttermaking largely moved from farms to small centrifuging plants called creameries (this page). People hearing the word “creamery” today usually don’t know that its prior associations were industrial, not pastoral, and it’s been appropriated by a spectrum of small-scale artisanal milk processors and even a few cheesemakers. “Creamery butter” in itself may or may not be better than any other butter.

  • Whipped butter: The dairy industry’s pseudo-solution to the pseudo-problem of chilled butter’s resistance to spreading. In the late 1960s someone had the idea of pumping butter full of nitrogen gas (sometimes air), which both softened the texture and handily increased the volume. Because of its reduced density, it cannot be substituted for plain butter in cooking. (Anyone who finds that regular butter won’t spread easily on bread should either put out a little butter to warm up to room temperature before using it or buy more substantial bread—you can’t expect mass-produced stuff with all the sturdy texture of marshmallow whip to be buttered without tearing into holes.) I skip whipped butter, with one odd but delightful exception: a version of the famous Russian butter made in Vologda, frequently sold in stores that carry imported foods from the ex–Soviet Union. It bears the words “Sweet Whipped Butter” prominently printed on the package below a Cyrillic label, and judging by the taste must be made from cream put through something like the English clotted-cream process. It’s just as hard to spread as any regular butter, but the flavor is phenomenal.

  • USDA butter grades: Marks (AA, A, B) assigned under a Department of Agriculture evaluation system that today unfortunately has no relevance to most of the butter sold in any retail venue. Most manufacturers decline to be involved in the voluntary grading program, and those that do go along don’t necessarily make better butter than the nonparticipants.

  WHAT YOU SEE AND WHAT YOU GET

  Judging the quality of butter from external factors is dicey. Price and distinguished-sounding Old World (or domestic) origins are no guarantee of anything. Neither is color. Butter can be any shade from nearly white to deep yellow, mostly depending on whether the vitamin A in the milkfat occurs in the finished form (colorless) or as the precursor beta-carotene (yellow). Jersey and Guernsey cows give the deepest-colored butter, Holstein-Friesians the palest. Butter from goats’, sheep’s, and buffaloes’ milk is always ivory-white. The color of cows’-milk butter can vary
by season, if the animals have access to spring pasturage (which puts more beta-carotene into the milk). Bear in mind that color has no necessary connection with butteriness; in some parts of the country where people strongly prefer a bright yellow, the color may come from dyes such as annatto.

  Real quality, as opposed to cosmetics, depends not only on how the butter was made but on whether it has been exposed to air or allowed to stand at warm temperatures between the time of manufacture and the time of consumption. Every few degrees of temperature above about 45° or 50°F mean some loss of volatile compounds, some irreversible shift in the intricacies of the fragile substance. Then there is the question of packaging. The onion experiment shows how quick butter is to react with its surroundings. Let it sit uncovered even at refrigerator temperatures, and it will soon oxidize enough to develop a discolored and greasy-looking outer layer. It also will either pick up the smell of other foods or simply lose its own pristine flavor. Moral: Tight, secure packaging in materials like foil or stout laminated cardboard—or both together—is a big plus in choosing butter. Some otherwise excellent butters come in flimsy, ill-sealed wrappings. If you take the plunge and buy these, then scrupulously rewrap them the minute you get them home in some impermeable arrangement like plastic wrap inside a layer of foil. (And maybe a freezer bag for good measure.) I don’t have a home vacuum-seal device, but it sounds like a useful idea for butter.

  Well-wrapped butter keeps quite well in the refrigerator and even better in the freezer. Salt butter has a longer life expectancy than unsalted, but it’s hard to give rules of thumb. Today refrigerated butter almost never goes spectacularly bad in the sense meant by the Beecher sisters; rather, it just keeps taking on whiffs of something slightly foreign while losing the luxe, calme, et volupté that set butter apart from other fats. It may still be quite good after a week’s or two weeks’ sojourn in the refrigerator, but the safest thing is to cut off a chunk for immmediate use and store the rest in the freezer, carefully wrapped. Here again there’s no hard and fast rule about storage times. Good, fresh butter that’s never been taken out of sealed packaging can last in excellent condition for many months.