Butter
For alternate meanings of the term, see Butter (disambiguation). |
Butter is commonly sold in sticks (pictured) or small blocks, and frequently served with the use of a butter knife. |
Butter is a
dairy product made by
churning fresh or
fermented cream or
milk. In many parts of the world, butter is an everyday food. Butter is used as a
spread and a
condiment, as well as in
cooking applications such as baking, sauce making, and frying. Butter consists of
butterfat surrounding minuscule droplets consisting mostly of
water and milk
proteins. The most common form of butter is made from
cows' milk, but can also be made from the milk of other
mammals, including
sheep,
goats,
buffalo, and
yaks.
Salt,
flavorings, or
preservatives are sometimes added to butter.
Rendering butter produces
clarified butter or
ghee, which is almost entirely butterfat.
When
refrigerated, butter remains a solid, but softens to a spreadable consistency at
room temperature, and melts to a thin liquid consistency at 32–35 °C (90–95 °F). Butter generally has a pale
yellow color, but varies from deep yellow to nearly white. The color of the butter depends on the animal's feed and is sometimes manipulated with
food colorings, most commonly
annatto or
carotene.
The term "butter" is used in the names of products made from
puréed nuts or
peanuts, such as
peanut butter. It is also used in the names of fruit products, such as
apple butter. Other
fats solid at room temperature are also known as "butters"; examples include
cocoa butter and
shea butter. In general use, the term "butter", unqualified, almost always refers to the dairy product. The word
butter, in the
English language, derives (via
Germanic languages) from the
Latin butyrum, borrowed from the
Greek boutyron. This may have been a construction meaning "cow-cheese" (
bous "ox, cow" +
tyros "cheese"), or the word may have been borrowed from another language, possibly
Scythian.
[Douglas Harper's Online Etymology Dictionary entry for butter. Retrieved 27 November 2005.] The root word persists in the
butyric acid found in
rancid butter and other rancid dairy products.
|
Today, commercial butter-making is a carefully-controlled operation. |
Unhomogenized milk and cream contain
butterfat in the form of microscopic globules. These globules are surrounded by
membranes made of
phospholipids (
fatty acid emulsifiers) and
proteins, which prevent the fat in milk from pooling together into a single mass. Butter is produced by agitating cream, which damages these membranes and allows the milk fats to conjoin, separating from the other parts of the cream. Variations in the production method will create butters with different consistencies, mostly due to the butterfat composition in the finished product. Butter contains fat in three separate forms: free butterfat, butterfat
crystals, and undamaged fat globules. In the finished product, different proportions of these forms result in different consistencies within the butter; butters with many crystals are harder than butters dominated by free fats.
Almost all commercially-made butter today begins with
pasteurized cream, which is commonly heated to a relatively high temperature above 80 °C (180 °F). Before it is churned, the cream is cooled to about 5 °C (40 °F) and allowed to remain at that temperature for at least eight hours; under these conditions about half the butterfat in the cream crystallizes. The jagged crystals of fat inflict damage upon the fat globule membranes during churning, speeding the butter-making process.
Churning produces small butter grains floating in the water-based portion of the cream. This watery liquid is called
buttermilk—although the buttermilk most common today is instead a directly fermented skimmed milk. The buttermilk is drained off; sometimes more buttermilk is removed by rinsing the grains with water. Then the grains are "worked": pressed and kneaded together. When prepared manually, this is done using wooden boards called
scotch hands. This consolidates the butter into a solid mass and breaks up embedded pockets of buttermilk or water into tiny droplets.
Commercial butter is about 80% butterfat and 15% water; traditionally-made butter may have as little as 65% fat and 30% water. Butterfat consists of many moderate-sized, saturated
hydrocarbon chain fatty acids. It is a
triglyceride, an
ester derived from
glycerol and three
fatty acid groups. Butter becomes
rancid when these chains break down into smaller components, like
butyric acid and
diacetyl.
Before modern factory butter making, cream was usually collected from several milkings and was therefore several days old and somewhat fermented by the time it was made into butter. Butter made from a fermented cream is known as
cultured butter. During fermentation, the cream naturally sours as
bacteria convert
milk sugars into
lactic acid. The fermentation process produces additional aroma compounds, including
diacetyl, which makes for a fuller-flavored and more "buttery" tasting product.
[McGee p. 35.] Today, cultured butter is usually made from pasteurized cream whose fermentation is produced by the introduction of
Lactococcus and
Leuconostoc bacteria.
Another method for producing cultured butter, developed in the 1970s, is to produce butter from fresh cream and then incorporate bacterial cultures and lactic acid. Using this method, the cultured butter flavor grows as the butter is aged in cold storage. For manufacturers, this method is more efficient since aging the cream used to make butter takes significantly more space than simply storing the finished butter product. A similar and even more efficient method is to add lactic acid and flavor compounds directly to the fresh-cream butter; while this more efficient process simulates the taste of cultured butter, the product produced is not considered real cultured butter.
Today, dairy products are often
pasteurized during production to kill
pathogenic bacteria and other
microbes. Butter made from pasteurized fresh cream is called
sweet cream butter. Production of sweet cream butter first became common in the 19th century, with the development of
refrigeration and the mechanical cream separator.
[McGee p. 33.] Butter made from fresh or cultured unpasteurized cream is called
raw cream butter. Raw cream butter has a "cleaner" cream flavor, without the cooked-milk notes that pasteurization introduces.
Throughout
Continental Europe, cultured butter is preferred, while sweet cream butter dominates in the United States and the
United Kingdom. Therefore, cultured butter is sometimes labeled
European-style butter in the United States. Raw cream butter is virtually unheard-of in the United States, and is rare in Europe as well.
[McGee p. 34.]Several
spreadable butters have been developed; these remain softer at colder temperatures and are therefore easier to use directly out of refrigeration. Some modify the makeup of the butter's fat through chemical manipulation of the finished product, some through manipulation of the cattle's feed, and some by incorporating
vegetable oils into the butter.
Whipped butter, another product designed to be more spreadable, is aerated via the incorporation of
nitrogen gas— normal air is not used, because doing so would encourage
oxidation and
rancidity.
All categories of butter are sold in both salted and unsalted forms. Salted butters have either fine, granular
salt or a strong
brine added to them during the working. Nations that favor sweet cream butter tend to favor salted butter as well, possibly reflecting the blander taste of uncultured butter. In addition to flavoring the butter, the addition of salt also acts as a
preservative.
Another important aspect of production is the amount of
butterfat in the finished product. In the United States, all products sold as "butter" must contain a minimum of 80% butterfat by weight; most American butters contain only slightly more than that, averaging around 81%. European-style butters generally have a higher ratio of up to 85% butterfat.
Clarified butter is butter with almost all of its water and milk solids removed, leaving almost-pure butterfat. Clarified butter is made by heating butter to its melting point and then allowing it to cool off; after settling, the remaining components separate by density. At the top,
whey proteins form a skin which is removed, and the resulting butterfat is then poured off from the mixture of water and
casein proteins that settle to the bottom.
Ghee is clarified butter which is brought to higher temperatures (120 °C/250 °F) once the water has cooked off, allowing the milk solids to brown. This process flavors the ghee, and also produces
antioxidants which help protect it longer from rancidity. Because of this, ghee can keep for six to eight months under normal conditions.
[McGee p. 37.] |
Ancient butter-making techniques were still practiced in the early 20th century. Picture taken from March 1914 National Geographic. |
Since even accidental agitation can turn cream into butter, it is likely that the invention of butter goes back to the earliest days of
dairying, perhaps in the
Mesopotamian area between 9000 and 8000
BCE. The earliest butter would have been from
sheep or
goat's milk;
cattle are not thought to have been
domesticated for another thousand years or so.
[Dates from McGee p. 10.] An ancient method of butter making, still used today in some parts of
Africa and the
Near East, is shown in the photo at right, taken in
Palestine. A goat skin is half filled with milk, then inflated with air and sealed. It is then hung with ropes on a tripod of sticks and rocked to and fro until the butter is formed.
Butter was certainly known in the classical
Mediterranean civilizations, but it does not seem to have been a common food, especially in Ancient
Greece or
Rome. In the warm Mediterranean climate, unclarified butter would spoil very quickly— unlike
cheese, it was not a practical method of preserving the benefits of milk. The people of ancient Greece and Rome seemed to consider butter a food fit more for the northern
barbarians. A play by the Greek comic poet
Anaxandrides refers to
Thracians as
boutyrophagoi, "butter-eaters".
[Dalby p. 65.] Pliny's
Natural History calls butter "the most delicate of food among barbarous nations", and goes on to describe its medicinal properties.
[Bostock and Riley translation. Book 28, chapter 35.]Historian and linguist Andrew Dalby says that most references to butter in ancient Near Eastern texts should actually be translated instead as
ghee. Ghee is mentioned in the
Periplus of the Erythraean Sea as a typical trade article around the 1st century CE
Arabian Sea, and Roman geographer
Strabo describes it as a commodity of
Arabia and
Sudan.
[Dalby p. 65.] In
India, ghee has been a symbol of purity and an offering to the gods—especially
Agni, the
Hindu god of fire—for more than 3000 years; references to ghee's sacred nature appear numerous times in the
Rig Veda, circa 1500–1200 BCE. The tale of the child
Krishna stealing butter remains a popular children's story in India today. Since India's prehistory, ghee has been both a
staple food and used for ceremonial purposes such as fueling holy lamps and funeral pyres.
|
Butter-making woman, Compost et Kalendrier des Bergères, Paris, 1499. |
Cooler climates in northern Europe allowed butter to be kept longer before spoiling.
Scandinavia has the longest history in Europe of a butter export trade, dating at least to the 12th century.
[Web Exhibits: Butter. Ancient Firkins.] Across most of Europe after the fall of Rome and through much of the
Middle Ages, butter was a common food, but one with a low reputation; it was consumed principally by
peasants. It slowly became more accepted by the upper class, especially when, in the early 16th century, the
Roman Catholic Church permitted its consumption during
Lent.
Bread and butter became common fare among the new
middle class, and the English, in particular, gained a reputation for their liberal use of melted butter as a sauce for meats and vegetables.
[McGee p. 33, "Ancient, Once Unfashionable".]Across far-northern Europe—
Ireland,
Scotland,
Iceland, and Scandinavia—butter was sometimes treated in a manner unheard-of today: it was packed into barrels (
firkins) and buried in
peat bogs, perhaps for years. Such "bog butter" would develop a strong flavor as it aged, but remain edible, in large part because of the unique cool, airless,
antiseptic and
acidic environment of a peat bog. Firkins of such buried butter are a common archaeological find in Ireland; the Irish National Museum has some containing "a grayish cheese-like substance, partially hardened, not much like butter, and quite free from putrefaction." The practice was most common in Ireland in the 11th–14th centuries; it ended entirely before the 19th century.
[Web Exhibits: Butter. Ancient Firkins.] France, like Ireland, became well-known for its butter, particularly in the
Normandy and
Brittany regions. By the 1860s, butter had become so in demand in France that Emperor
Napoleon III offered prize money for an inexpensive substitute to supplement France's inadequate butter supplies. In 1869, a
French chemist claimed the prize with the invention of
margarine. The first margarine was
beef tallow flavored with milk and worked like butter; vegetable margarines followed after the development of
hydrogenated oils around 1900.
Until the 19th century, the vast majority of butter was made by hand, on farms. The first butter factories appeared in the United States in the early 1860s, after the successful introduction of
cheese factories a decade earlier. In the late 1870s, the
centrifugal cream separator was introduced, marketed most successfully by
Swedish engineer
Carl Gustaf Patrik de Laval. This dramatically sped the butter-making process by eliminating the slow step of letting cream naturally rise to the top of milk. Initially, whole milk was shipped to the butter factories, and the cream separation took place there. Soon, though, cream-separation technology became small and inexpensive enough to introduce an additional efficiency: the separation was accomplished on the farm, and the cream alone shipped to the factory. By 1900, more than half the butter produced in the United States was factory made; Europe followed suit shortly after.
Per capita butter consumption declined in most western nations during the 20th century, in large part because of the rising popularity of margarine, which is less expensive and, until recent years, was perceived as being healthier. In the United States, margarine consumption overtook butter during the 1950s
[Web Exhibits: Butter. Eating less butter, and more fat.] and it is still the case today that more margarine than butter is eaten in the U.S. and most other nations that track such data.
[See for example this chart from International Margarine Association of the Countries of Europe statistics. Retrieved 4 December 2005.]India produces and consumes more butter than any other nation, dedicating almost half of its annual milk production to making butter or
ghee. In 1997, India produced 1,470,000
metric tons of butter, consuming almost all of it. Second in production was the United States (522,000 tons), then France (466,000),
Germany (442,000), and
New Zealand (307,000). In terms of consumption, Germany was second after India, using 578,000 tons of butter in 1997, followed by France (528,000),
Russia (514,000), and the United States (505,000). Most nations produce and consume the bulk of their butter domestically. New Zealand,
Australia, and the
Ukraine are among the few nations that export a significant percentage of the butter they produce.
[Statistics from USDA Foreign Agricultural Service (1999). Dairy: Word Markets and Trade. Retrieved 1 December 2005. Note that the export and import figures do not include trade between nations within the European Union, and that there are inconsistencies regarding the inclusion of clarified butterfat products (explaining why New Zealand is shown exporting more butter in 1997 than was produced).]Different varieties of butter are found around the world.
Smen is a spiced
Moroccan clarified butter, buried in the ground and aged for months or years.
Yak butter is important in
Tibet;
tsampa,
barley flour mixed with yak butter, is a staple food.
Butter tea is consumed in the
Himalayan regions of Tibet,
Bhutan,
Nepal and India. It consists of
tea served with intensely flavored — or "rancid"—yak butter and salt. In
African and
Asian
developing nations, butter is traditionally made from sour milk rather than cream. It can take several hours of churning to produce workable butter grains from fermented milk.
[Crawford et al, part B, section III, ch. 1: Butter. Retrieved 28 November 2005.]Normal butter softens to a spreadable consistency around 15 °C (60 °F), well above
refrigerator temperatures. The "butter compartment" found in many refrigerators may be one of the warmer sections inside, but it still leaves butter quite hard. Until recently, many refrigerators sold in
New Zealand featured a "butter conditioner", a compartment kept warmer than the rest of the refrigerator—but still cooler than room temperature—with a small heater.
[Bring back butter conditioners. Retrieved 27 November 2005. The feature has been phased out for energy conservation reasons.] Keeping butter tightly wrapped delays rancidity, which is hastened by exposure to light or air, and also helps prevent it from picking up other odors. Wrapped butter has a shelf life of several months at refrigerator temperatures.
[According to joyofbaking.com, unsalted butter can last for up to three months and salted butter up to five.]"French butter dishes" or "
Acadian butter dishes" involve a lid with a long interior lip, which sits in a container holding a small amount of water. Usually the dish holds just enough water to submerge the interior lip when the dish is closed. Butter is packed into the lid. The water acts as a seal to keep the butter fresh, and also keeps the butter from overheating in hot temperatures. This allows butter to be safely stored on the countertop for several days without spoilage.
Once butter is softened,
spices,
herbs, or other flavoring agents can be mixed into it, producing what is called a
composed butter or
composite butter. Composed butters can be used as spreads, or cooled, sliced, and placed onto hot food to melt into a sauce. Sweetened composed butters can be served with
desserts; such
hard sauces are often flavored with
spirits.
Melted butter plays an important role in the preparation of
sauces, most obviously in
French cuisine.
Beurre noisette (hazel butter) and
Beurre noir (black butter) are sauces of melted butter cooked until the milk solids and sugars have turned golden or dark brown; they are often finished with an addition of
vinegar or
lemon juice.
Hollandaise and
béarnaise sauces are
emulsions of
egg yolk and melted butter; they are in essence
mayonnaises made with butter instead of oil. Hollandaise and béarnaise sauces are stabilized with the powerful
emulsifiers in the egg yolks, but butter itself contains enough emulsifiers—mostly remnants of the fat globule membranes—to form a stable emulsion on its own.
Beurre blanc (white butter) is made by whisking butter into reduced vinegar or
wine, forming an emulsion with the texture of thick cream.
Beurre monté (prepared butter) is an unflavored
beurre blanc made from water instead of vinegar or wine; it lends its name to the practice of "mounting" a sauce with butter: whisking cold butter into any water-based sauce at the end of cooking, giving the sauce a thicker body and a glossy shine—as well as a buttery taste.
[Sauce information from McGee, pp. 36 (beurre noisette and beurre noir), 632 (beurre blanc and beurre monté), and 635–636 (hollandaise and béarnaise).]Butter is used for
sautéing and
frying, although its milk solids brown and burn above 150 °C (250 °F)—a rather low temperature for most applications. The actual
smoke point of butterfat is around 200 °C (400 °F), so clarified butter or ghee is better suited to frying.
[McGee p. 37.] Ghee has always been a common frying medium in India, where many avoid other animal fats for cultural or religious reasons.
Butter fills several roles in
baking, where it is used in a similar manner as other solid fats like
lard,
suet, or
shortening, but has a flavor that may better complement sweet baked goods. Many
cookie doughs and some
cake batters are
leavened, at least in part, by
creaming butter and
sugar together, which introduces air bubbles into the butter. The tiny bubbles locked within the butter expand in the heat of baking and aerate the cookie or cake. Some cookies like
shortbread may have no other source of moisture but the water in the butter.
Pastries like
pie dough incorporate pieces of solid fat into the dough, which become flat layers of fat when the dough is rolled out. During baking, the fat melts away, leaving a flaky texture. Butter, because of its flavor, is a common choice for the fat in such a dough, but it can be more difficult to work with than shortening because of its low melting point. Pastry makers often chill all their ingredients and utensils while working with a butter dough.
According to
USDA figures, one
tablespoon of butter (14
grams) contains 100
calories, all from fat, 11 grams of fat, of which 7 grams are
saturated fat, and 30
milligrams of
cholesterol.
[Data from nutritiondata.com. Retrieved 27 November 2005.] In other words, butter consists mostly of saturated fat and is a significant source of dietary cholesterol. For these reasons, butter has been generally considered to be a contributor to health problems, especially
heart disease. For many years, vegetable margarine was recommended as a substitute, since it is an unsaturated fat and contains little or no cholesterol. In recent decades, though, it has become accepted that the
trans fats contained in partially
hydrogenated oils used in typical margarines significantly raise "bad"
LDL cholesterol levels as well.
[Q&A about Saturated Fat, Trans Fat, and Cholesterol from the (U.S.) National Heart, Lung and Blood Institute (2005). Retrieved 15 April 2006.] Trans-fat free margarines have since been developed.
Small amounts of butter contain only traces of
lactose, so moderate consumption of butter is not generally a problem for those with
lactose intolerance.
[From data here, one teaspoon of butter contains 0.03 grams of lactose; a cup of milk contains 400 times that amount.] People with
milk allergies do need to avoid butter, which does contain enough of the allergy-causing proteins to cause reactions.
[Allergy Society of South Africa. Milk Allergy & Intolerance. Retrieved 27 November 2005.]
*
Composition and characteristics of butter, The Canadian Dairy Commission*
Manufacture of butter, The University of Guelph*
Cooking For Engineers: Making Butter - how to make butter at home with step-by-step photos and discussion
