Milk (11 page)

The third crucial achievement was
homogenization, or the technique of crushing milkfat globules into droplets too small to rise to the surface in a cream layer. Homogenization had to overcome several obstacles before it could be coupled with the first two advances. It disrupted the chemical structure of the milkfat so drastically as to release a torrent of enzymes that promptly turned raw milk rancid. Even when dairy chemists learned to sidestep
rancidity by combining the steps of pasteurizing (which inactivated the enzymes) and homogenizing, there remained the age-old consumer habit of judging milk by its richness—i.e., the thickness of the cream layer on top. When packaging in glass bottles came in toward the start of the twentieth century, one of its advantages from a buyer’s point of view was the plainly visible “
creamline.” The fact that homogenized milk in glass tended to acquire an unpleasant oxidized flavor on exposure to light more rapidly than creamline milk was another strike against it.

As a result, until shortly after World War II few people saw any reason to want homogenized milk. Milk for drinking was almost without exception available in only two degrees of richness: with or without all the original fat.
Skim milk, or what was left when the cream was separated for other purposes, was the ugly sister. Health experts warned mothers that it was paltry stuff, deficient in crucial nutrients. (Most states required that it be fortified with
vitamin A to replace the fat-soluble beta-carotene that disappeared along with the cream; this step is still mandatory for fat-free and most reduced-fat milk.) At the nation’s creameries skim milk was an unvalued by-product, often dumped for lack of any profitable use.

As early as the late 1930s a few dairy processors had been trying to win people over to homogenized milk. The turning point came with a postwar shift to opaque paper or
cardboard containers in place of returnable milk bottles. This
in turn accompanied another shift away from home delivery and toward supermarket purchases of milk. Consumers and supermarket managers adored the convenience of throwaway packaging, Milk processors and distributors loved the fact that cardboard couldn’t be seen through, which incidentally solved the oxidation problem. It was the perfect moment for abolishing
creamline milk and substituting a product whose appearance had previously weighed against it.

From an industry perspective, homogenization meant not simply homogenizing milk as it came from Bessy, Ellen, or Lucinda but being able to play with it. A commercial
dairy could now calculate the amount of fat in incoming milk, completely remove it, and homogenize it back into the milk
in any desired proportion,
while putting any surplus to other purposes such as
butter or
ice cream. In effect, “
whole milk” could now be whatever the industry said it was.

Publicity campaigns successfully persuaded housewives that homogenized milk was both handier and—a particularly Orwellian stroke—creamier-tasting than messy old-fashioned milk with the cream on top. The fact that few milk drinkers now had ever met a cow was a great help. Very soon even the few diehards who preferred milk in glass had forgotten about creamlines, and today curiosity seekers tasting unhomogenized milk for the first time often find the appearance and “mouthfeel” vaguely unnatural. The dairy-processing industry was free to set the standard milkfat content for supposedly “whole” milk at 3.25 percent by weight—the minimum specified by the
Food and Drug Administration in the Code of Federal Regulations, though some states mandate a slightly higher percentage.

In 1929 a survey of the composition of milk produced by major dairy-cow breeds showed milkfat ranges from 2.9 to 8.4 percent; though a similar listing today would show some ironing-out of extremes, a real average for American dairy herds probably would be around 4 percent, with the best herds easily achieving 5 or 5.5 percent. Yet after more than half a century of almost universal homogenization, it would be fiscal insanity for most processors to sell anything mirroring the composition of real whole milk. Indeed, consumers have trouble grasping that the usual homogenized product is
not
whole, in the sense of being entire or intact.

This tale of pseudo-progress must be seen against a backdrop of permanent crises in milk allocation. As dairy farming became more capital-intensive and productivity per cow increased, chronic supply-and-demand mismatches arose that led to
price regulation during the New Deal era. I will not attempt to describe the labyrinthine
USDA milk price–support system, which baffles my
comprehension and probably hasn’t been understood by the last five secretaries of agriculture. Suffice it to say that for about seventy years the prices paid to
dairy farmers have been calculated by formulas based on both geographical location and intended use, meant to ensure a steady supply of drinkable fresh milk from rural dairying regions to population centers. “Class I” fluid milk for drinking occupies a privileged rank and ordinarily commands the highest prices, while most of the milk destined for other uses (for instance, in butter, cheese, powdered milk, and various manufactured foods) is placed in a confusing array of generally less lucrative pigeonholes. It probably will surprise no one to learn that, regulatory machinery or no, the country is periodically flooded with regional or nationwide surpluses of fresh fluid milk, while many (perhaps most) dairy farmers barely break even.

Special-interest gimmickry promised an out. Dairy processors had investigated it to an extent after World War I, the success story of chocolate milk being one 1920s example. But their efforts were mere dabbling until the miracle of “standardization” by
homogenizing came along. And even that might not have had the spectacular results it did if not for a swift reversal of
nutritional orthodoxy about the benefits of
whole versus
skim milk during the late-twentieth-century cardiac donnybrooks summarized further on (
this page
). Suddenly milkfat was not proof of quality, but one of nature’s blunders in designing an otherwise virtuous food. From the ’60s or ’70s on, hasty public-health re-education campaigns sought to convert consumers to “the less, the better” attitudes regarding fat percentages in milk, with zero being the new ideal.

Zero was easily attainable through
centrifuging, but centrifuged skim milk lacked the flavor-saving smidgin of cream that remained in the milk after hand skimming. Some people uncomplainingly adopted zero-fat milk; many more balked. The milk-processing industry eventually arrived at a spectrum of products starting with 0 percent milkfat milk and progressing through various homogenized gradations of fat content: 0.5 percent (officially “
low-fat”), 1 percent, 1.5 percent, and 2 percent (these last three “
reduced-fat”). Not all are equally available everywhere, but in most states you will find at least three or four of them. All quickly acquired fan clubs that are now an entrenched part of American culture. For a long time the hardest sell remained skim milk, and for good reason: The usual commercial versions are a singularly thin, vapid travesty of decent hand-skimmed milk. But eventually processors hit on the stratagem of using dried skim milk solids to add body and selling the result under names like “Skim Milk Plus.” (Despite any promotional malarkey on the label, the real difference between this and plain skim milk is not extra “creaminess” or “richness” but more
lactose and
casein.)

Other possibilities opened up with news of the
lactose-tolerance issue,
which began reaching consumers in the 1970s and seriously sank in about a decade later. Instead of acknowledging that people do not in the least need to drink fresh milk, dairy chemists eagerly began working to produce something that would approximate fresh milk without the usual lactose content. In all fairness, this head-in-the-sand approach must be attributed less to industry guile than to cultural biases so deep that even intelligent public-health advocates don’t recognize them as biases.

Making lactose-free milk turned out to be far more difficult than making fat-free milk.
Lactic-acid bacteria do it all the time—but no one wanted the souring and thickening that are part of their wizardry. Instead, the human wizards had to directly expose milk to the lactase enzyme. Unfortunately for flavor, the result was a release of very sweet free
glucose into the milk when the original lactose—one of the
least
sweet sugars in nature—was enzymatically chopped into
galactose and glucose. More recently, advanced techniques have been developed to physically extract the lactose from the milk instead of splitting it into component sugars. No technique so far makes lactose-free or
lactose-reduced milk taste particularly like plain unmodified milk. Taste, however, doesn’t seem to be the point.

Regardless of the new products’ deficiencies, they have brought us still more value-added categories of fluid milk. Along with the aforementioned kinds of fat-free or reduced-fat milk, supermarket dairy cases now display lactose-free or reduced-lactose “whole” (i.e., homogenized 3.25 percent), skim, 1 percent, and 2 percent milk. If your head isn’t already spinning from this surfeit of choices, some retail sources also tout
calcium-fortified milk—either “whole” or reduced-fat, full-lactose or reduced-lactose. Why add calcium to a food that already happens to be a rich source of calcium? Well, call it the Nothing Succeeds like Excess theory of nutrition. Despite the fact that neither osteoporosis nor childhood skeletal maldevelopment is more prevalent among well-nourished people in societies where no one consumes milk than in the United States, it would take a lot to displace the “no milk, no strong bones” syllogism from popular nutrition education. You can even buy milk fortified with fiber, undoubtedly in response to some perception of a market.

Among the final absurdities in this sequence of nutritional bad jokes is the rehabilitation of “
filled” and
imitation milks, once synonymous with cheap impostures. In the era when creameries were awash in unwanted skim milk, various quick-buck artists conceived the idea of buying it up for a song and emulsifying (“filling”) it with some kind of vegetable oil, perhaps partially hydrogenated to mimic the “mouthfeel” of the milkfat in whole milk. Dairymen’s associations and health experts—who in those days usually furthered each other’s agendas—denounced the budget-price results as unwholesome shams. They were still louder in condemning the nutritional deficiencies of
“imitation milks” compounded from vegetable oil, sugar, corn-syrup solids, some protein source, and emulsifiers.

Who could have foreseen that one day we would see these old ringers peddled in new guises as more
healthful than what now passes for plain milk? The
American Heart Association serenely certifies a product called SunMilk, made by emulsifing skim milk with sunflower oil. Soy-based imitation milks are rapidly encroaching on real fluid-milk sales. Quite unrelated to the plain fresh
soy milk sold in small Chinatown groceries, they are created from improbable farragoes of ingredients with heavy doses of sugar and added flavorings to counteract an underlying “beany” pong. Today’s dairy aisles are crammed with filled milk and soy milk in such flavors as strawberry, chocolate, green tea, and mango, proudly billed as “lactose-free,” “casein-free,” “cholesterol-free,” and “heart-healthy.” Dairy farmers may regard the trend with dismay—but not the world’s largest conglomerate of milk processors, Dean Foods, which has hedged its bets by acquiring the Silk and Sun Soy brands of soy milk.

Can this spectacle get any crazier? It can and will. Dairying experts everywhere are trying to see whether adding substances like fish oil to dairy cows’ rations will result in milk with more un
saturated fatty acids. It has been difficult to administer feed supplements that won’t either impart off flavors to the milk or end up being turned into saturated fatty acids after all by the ruminal bacteria. But at least one success story is now on retail shelves in Ontario: Dairy Oh!, developed by members of the University of Guelph’s renowned dairy science department. Similar products will eventually jostle for U.S. shoppers’ attention with the already dizzying roster of value-added twists on milk that we now take for granted.

We all know the reason behind the bastardized products flooding the market: the reputation as a killer that milk acquired during successive debates on
heart disease in the last half of the twentieth century. Today a great deal of the diet-and-cardiac-mortality gospel as originally promulgated has had to be profoundly revised or, in some cases, thrown out. But for some reason the milk parts of the creed have never come in for serious re-examination.

Many facts of the case are undisputed. In the first place milkfat as found in all full-fat dairy products is very rich in saturated fatty acids. (For the nuts and bolts of the saturation concept, see the description of butter,
this page
.) Beginning as
unsaturated precursors in the fresh grasses or hay eaten by the cow, these acquire their saturated form in the great chemist’s workshop of the
rumen with its population of fermenting bacteria. The same is true of other ruminants like
goats,
sheep, and
water buffaloes. All produce milkfat with
more saturated fatty acids than any vegetable-derived fats except coconut oil, palm oil, and palm-kernel oil.

The picture is clear from a few simple comparisons. A 100-gram portion of most commercially available vegetable oils contains about 10 to 18 grams of saturated fatty acids and 82 to 90 grams total
unsaturated fatty acids, with widely varying proportions of monounsaturated to
polyunsaturated fatty acids. The figures for olive oil are about 14 grams saturated fatty acids, 77 grams
monounsaturated fatty acids, and 9 grams polyunsaturated fatty acids. But 100 grams of cows’-milk butter that has had the water mechanically removed would—allowing for large variations in composition among different animals—probably average out at roughly 62 grams saturated fatty acids, 29 grams monounsaturated fatty acids, and 4 grams polyunsaturated fatty acids together with a few grams of other milk-derived substances.