Cheese is a type ofdairy product produced in a range of flavors,textures, and forms bycoagulation of the milk proteincasein. It comprisesproteins and fat from milk (usually the milk ofcows,buffalo,goats orsheep). During production, milk is usuallyacidified and either the enzymes ofrennet or bacterial enzymes with similar activity are added to cause the casein to coagulate. The solidcurds are then separated from the liquidwhey and pressed into finished cheese.[1] Some cheeses have aromaticmolds on the rind, the outer layer, or throughout.
Over a thousandtypes of cheese exist, produced in various countries. Their styles, textures and flavors depend on the origin of the milk (including the animal's diet), whether they have beenpasteurised, thebutterfat content, the bacteria andmold, the processing, and how long they have beenaged. Herbs, spices, orwood smoke may be used asflavoring agents. Other added ingredients may includeblack pepper, garlic,chives orcranberries. A cheesemonger, or specialist seller of cheeses, may have expertise with selecting, purchasing, receiving, storing and ripening cheeses.[2]
Most cheeses are acidified by bacteria, which turnmilk sugars intolactic acid; the addition of rennet completes the curdling. Vegetarian varieties of rennet are available; most are produced throughfermentation by the fungusMucor miehei, but others have been extracted fromCynara thistles. For a few cheeses, the milk iscurdled by addingacids such as vinegar orlemon juice.
Cheese is valued for its portability, longshelf life, and high content of fat, protein,calcium, andphosphorus. Cheese is more compact and has a longer shelf life than milk.[3]Hard cheeses, such asParmesan, last longer than soft cheeses, such asBrie orgoat's milk cheese. The long storage life of some cheeses, especially when encased in a protective rind, allows selling when markets are favorable.Vacuum packaging of block-shaped cheeses andgas-flushing of plastic bags with mixtures ofcarbon dioxide andnitrogen are used for storage andmass distribution of cheeses in the 21st century,[3] compared with the paper and twine that was used in the 20th and 19th century.
Old Englishcyse (West Saxon),cese (Anglian) ... from West Germanic *kasjus (source also of Old Saxonkasi, Old High Germanchasi, GermanKäse, Middle Dutchcase, Dutchkaas), from Latincaseus [for] "cheese" (source of Italiancacio, Spanishqueso, Irishcaise, Welshcaws).
TheOnline Etymological Dictionary states that the word is of:[5]
unknown origin; perhaps from a PIE root *kwat- "to ferment, become sour" (source also of Prakritchasi "buttermilk;" Old Church Slavonickvasu "leaven;fermented drink,"kyselu "sour," -kyseti "to turn sour;" Czechkysati "to turn sour, rot;" Sanskrit kvathati "boils, seethes;" Gothic hwaþjan "foam").
When the Romans began to make hard cheeses for theirlegionaries' supplies, a new word started to be used:formaticum, fromcaseus formatus, or "cheese shaped in a mold". It is from this word that the Frenchfromage, standard Italianformaggio,Catalanformatge,Bretonfourmaj, andOccitanfromatge (orformatge) are derived. Of the Romance languages, Spanish,Portuguese,Romanian,Tuscan and some Southern Italian dialects use words derived fromcaseus (queso,queijo,caș,cacio andcaso for example). The wordcheese is occasionally employed, as inhead cheese, to mean "shaped in a mold".[6][7]
A piece of soft curd cheese, oven-baked to increaseshelf life
Cheese is an ancient food whose originspredate recorded history. There is no conclusive evidence indicating where cheesemaking originated, whether inEurope,Central Asia or theMiddle East. The earliest proposed dates for the origin of cheesemaking range from around 8000 BCE, when sheep were firstdomesticated. Because animal skins and inflated internal organs have provided storage vessels for a range of foodstuffs since ancient times, it is probable that the process of cheese making was discovered accidentally by storing milk in a container made from the stomach of an animal, resulting in the milk being turned tocurd andwhey by the rennet from the stomach.[8] There is alegend—with variations—about the discovery of cheese by an Arab trader who used this method of storing milk.[9]
The earliest evidence of cheesemaking in the archaeological record dates back to 5500 BCE and is found in what is nowKuyavia, Poland, where strainers coated withmilk-fat molecules have been found.[10][11] The earliest evidence of cheesemaking in theMediterranean dates back to 5200 BCE, on the coast of theDalmatia region ofCroatia.[12]
Cheesemaking may have begun independently of this by the pressing and salting of curdled milk to preserve it. Observation that the effect of making cheese in an animal stomach gave more solid and better-textured curds may have led to the deliberate addition of rennet. Earlyarcheological evidence ofEgyptian cheese has been found inEgyptian tomb murals, dating to about 2000 BCE.[13] A 2018 scientific paper stated that cheese dating to approximately 1200 BCE (3200 years before present), was found in ancient Egyptian tombs.[14][15] The earliest ever discovered preserved cheese was found on mummies inXiaohe Cemetery in the Taklamakan Desert inXinjiang, China, dating back as early as 1615 BCE.[16][17][18]
The earliest cheeses were likely quite sour and salty, similar in texture to rusticcottage cheese orfeta, a crumbly, flavorful Greek cheese. Cheese produced in Europe, where climates are cooler than the Middle East, required less salt for preservation. With less salt and acidity, the cheese became a suitable environment for usefulmicrobes and molds, giving aged cheeses their respective flavors.
We soon reached his cave, but he was out shepherding, so we went inside and took stock of all that we could see. His cheese-racks were loaded with cheeses, and he had more lambs and kids than his pens could hold...
When he had so done he sat down and milked his ewes and goats, all in due course, and then let each of them have her own young. He curdled half the milk and set it aside in wicker strainers.[19]
Columella'sDe Re Rustica (c. 65 CE) details a cheesemaking process involving rennet coagulation, pressing of the curd, salting, and aging. According toPliny the Elder, it had become a sophisticated enterprise by the time theRoman Empire came into being.[20] Pliny the Elder also mentions in his writingsCaseus Helveticus, a hardSbrinz-like cheese produced by theHelvetii.[21][22] Cheese was an everyday food and cheesemaking a mature art in the Roman empire.[23]Pliny'sNatural History (77 CE) devotes a chapter (XI, 97) to describing the diversity of cheeses enjoyed by Romans of the early Empire. He stated that the best cheeses came from the villages nearNîmes, but did not keep long and had to be eaten fresh. Cheeses of theAlps andApennines were as remarkable for their variety then as now. ALigurian cheese was noted for being made mostly from sheep's milk, and some cheeses produced nearby were stated to weigh as much as a thousand pounds each. Goats' milk cheese was a recent taste in Rome, improved over the "medicinal taste" ofGaul's similar cheeses bysmoking. Of cheeses from overseas, Pliny preferred those ofBithynia in Asia Minor.[24]
Until its modern spread along with European culture, cheese was nearly unheard of in east Asian cultures and in the pre-Columbian Americas and had only limited use in sub-Mediterranean Africa, mainly being widespread and popular only in Europe, the Middle East, theIndian subcontinent,[citation needed]Tibet,[30][31] and areas influenced by those cultures. But with the spread, first of European imperialism, and later of Euro-American culture and food, cheese has gradually become known and increasingly popular worldwide.
The first factory for the industrial production of cheese opened in Switzerland in 1815, but large-scale production first found real success in the United States. Credit usually goes to Jesse Williams, a dairy farmer fromRome, New York, who in 1851 started making cheese in anassembly-line fashion using the milk from neighboring farms; this made cheddar cheese one of the first USindustrial foods.[32] Within decades, hundreds of such commercial dairy associations existed.[33]
The 1860s saw the beginnings of mass-produced rennet, and by the turn of the century scientists were producing pure microbial cultures. Before then, bacteria in cheesemaking had come from the environment or from recycling an earlier batch's whey; the pure cultures meant a more standardized cheese could be produced.[34]
Factory-made cheese overtook traditional cheesemaking in theWorld War II era, and factories have been the source of most cheese in America and Europe ever since.[35] By 2012, cheese was one of the mostshoplifted items from supermarkets worldwide.[36]
In 2022, world production of cheese from whole cow milk was 22.6 milliontonnes, with the United States accounting for 28% of the total, followed by Germany, France, Italy and theNetherlands as secondary producers (table).
As of 2021, thecarbon footprint of a kilogram of cheese ranged from 6 to 12 kg ofCO2eq, depending on the amount of milk used; accordingly, it is generally lower than beef or lamb, but higher than other foods.[38]
Consumption
France, Iceland, Finland, Denmark and Germany were the highest consumers of cheese in 2014, averaging 25 kg (55 lb) per person per annum.[39]
In industrial production ofEmmental cheese, the as-yet-undrained curd is broken by rotating mixers.
A required step in cheesemaking is to separate the milk into solidcurds and liquidwhey. Usually this is done by acidifying (souring) the milk and addingrennet. The acidification can be accomplished directly by the addition of an acid, such as vinegar, in a few cases (paneer,queso fresco). More commonlystarter bacteria are employed instead which convertmilk sugars intolactic acid. The same bacteria (and theenzymes they produce) also play a large role in the eventual flavor of aged cheeses. Most cheeses are made with starter bacteria from theLactococcus,Lactobacillus, orStreptococcus genera.[citation needed]
Some fresh cheeses are curdled only by acidity, but most cheeses also use rennet. Rennet sets the cheese into a strong and rubberygel compared to the fragile curds produced by acidic coagulation alone. It also allows curdling at a lower acidity—important because flavor-making bacteria are inhibited in high-acidity environments. In general, softer, smaller, fresher cheeses are curdled with a greater proportion of acid to rennet than harder, larger, longer-aged varieties.[citation needed]
While rennet was traditionally produced via extraction from the inner mucosa of the fourth stomach chamber of slaughtered young, unweaned calves, most rennet used today in cheesemaking is producedrecombinantly.[41] The majority of the applied chymosin is retained in the whey and, at most, may be present in cheese in trace quantities. In ripe cheese, the type and provenance of chymosin used in production cannot be determined.[41]
Curd processing
At this point, the cheese has set into a very moist gel. Some soft cheeses are now essentially complete: they are drained, salted, and packaged. For most of the rest, the curd is cut into small cubes. This allows water to drain from the individual pieces of curd.
Some hard cheeses are then heated to temperatures in the range of 35–55 °C (95–131 °F). This forces more whey from the cut curd. It also changes the taste of the finished cheese, affecting both the bacterial culture and the milk chemistry. Cheeses that are heated to the higher temperatures are usually made withthermophilic starter bacteria that survive this step—eitherLactobacilli orStreptococci.
Salt has roles in cheese besides adding a salty flavor. It preserves cheese from spoiling, draws moisture from the curd, and firms cheese's texture in an interaction with itsproteins. Some cheeses are salted from the outside with dry salt or brine washes. Most cheeses have the salt mixed directly into the curds.
Other techniques influence a cheese's texture and flavor. Some examples are:
Stretching (Mozzarella,Provolone): the curd is stretched and kneaded in hot water, developing a stringy, fibrous body.
Cheddaring (Cheddar, other English cheeses): the cut curd is repeatedly piled up, pushing more moisture away. The curd is also mixed (ormilled) for a long time, taking the sharp edges off the cut curd pieces and influencing the final product's texture.
Washing: (Edam,Gouda,Colby): the curd is washed in warm water, lowering its acidity and making for a milder-tasting cheese.
Most cheeses achieve their final shape when the curds are pressed into a mold or form. The harder the cheese, the more pressure is applied. The pressure drives out moisture—the molds are designed to allow water to escape—and unifies the curds into a single solid body.
A newborn cheese is usually salty yet bland in flavor and, for harder varieties, rubbery in texture. These qualities are sometimes enjoyed—cheese curds are eaten on their own—but normally cheeses are left to rest under controlled conditions. This aging period (also called ripening, or, from the French,affinage) lasts from a few days to several years. As a cheese ages, microbes and enzymes transform texture and intensify flavor. This transformation is largely a result of the breakdown of casein proteins andmilkfat into a complex mix ofamino acids,amines, andfatty acids.
Some cheeses have additional bacteria ormolds intentionally introduced before or during aging. In traditional cheesemaking, these microbes might be already present in the aging room; they are allowed to settle and grow on the stored cheeses. More often today, prepared cultures are used, giving more consistent results and putting fewer constraints on the environment where the cheese ages. These cheeses include soft ripened cheeses such asBrie andCamembert; blue cheeses such asRoquefort,Stilton,Gorgonzola; andrind-washed cheeses such asLimburger.
There are many types of cheese, with around 500 different varieties recognized by the International Dairy Federation,[42] more than 400 identified by Walter and Hargrove, more than 500 by Burkhalter, and more than 1,000 by Sandine and Elliker.[43] The varieties may be grouped or classified into types according to criteria such as length of ageing, texture, methods of making, fat content, animal milk, country or region of origin, etc.—with these criteria either being used singly or in combination,[44] but with no single method being universally used.[45] The method most commonly and traditionally used is based on moisture content, which is then further discriminated by fat content and curing or ripening methods.[42][46] Some attempts have been made to rationalise the classification of cheese—a scheme was proposed by Pieter Walstra which uses the primary and secondary starter combined with moisture content, and Walter and Hargrove suggested classifying by production methods which produces 18 types, which are then further grouped by moisture content.[42]
The British Cheese Board once claimed that Britain had approximately 700 distinct local cheeses;[47] France andItaly have perhaps 400 each (a French proverb holds there is a different French cheese for every day of the year, andCharles de Gaulle once asked "how can you govern a country in which there are 246 kinds of cheese?").[48]
Atrefrigerator temperatures, the fat in a piece of cheese is as hard as unsoftened butter, and its protein structure is stiff as well. Flavor and odor compounds are less easily liberated when cold. For improvements in flavor and texture, it is widely advised that cheeses be allowed to warm up toroom temperature before eating. If the cheese is further warmed, to 26–32 °C (79–90 °F), the fats will begin to "sweat out" as they go beyond soft to fully liquid.[49]
Above room temperatures, most hard cheeses melt. Rennet-curdled cheeses have agel-like protein matrix that is broken down by heat. When enough protein bonds are broken, the cheese itself turns from a solid to a viscous liquid. Soft, high-moisture cheeses will melt at around 55 °C (131 °F), while hard, low-moisture cheeses such as Parmesan remain solid until they reach about 82 °C (180 °F).[49] Acid-set cheeses, includinghalloumi,paneer, some whey cheeses and many varieties of freshgoat cheese, have a protein structure that remains intact at high temperatures. When cooked, these cheeses just get firmer as water evaporates.
Some cheeses, likeraclette, melt smoothly; many tend to become stringy or suffer from a separation of their fats. Many of these can be coaxed into melting smoothly in the presence of acids orstarch.Fondue, with wine providing the acidity, is a good example of a smoothly melted cheese dish.[49] Elastic stringiness is a quality that is sometimes enjoyed, in dishes includingpizza andWelsh rarebit. Even a melted cheese eventually turns solid again, after enough moisture is cooked off. The saying "you can't melt cheese twice" (meaning "some things can only be done once") refers to the fact that oils leach out during the first melting and are gone, leaving the non-meltable solids behind.
As its temperature continues to rise, cheese willbrown and eventually burn. Browned, partially burned cheese has a particular distinct flavor of its own and is frequently used in cooking (e.g., sprinkling atop items before baking them).
Acheeseboard (or cheese course) may be served at the end of a meal before or following dessert, or replacing the last course. The British tradition is to have cheese after dessert, accompanied by sweet wines likeport. In France, cheese is consumed before dessert, with robust red wine.[50][51] A cheeseboard typically has contrasting cheeses with accompaniments, such as crackers, biscuits, grapes, nuts, celery orchutney.[51]
A cheeseboard 70 feet (21 m) long was used to feature the variety of cheeses manufactured inWisconsin,[52] where thestate legislature recognizes a "cheesehead" hat as a state symbol.[53]
Nutrition and health
The nutritional value of cheese varies widely. Low-fatcottage cheese is 2% fat and 11%protein while dry queso seco cheese is 24% fat and 25% protein, and full-fatcream cheese is 34% fat and 6% protein.[54] In general, cheese is a rich source (20% or more of theDaily Value, DV) ofcalcium,protein,phosphorus,sodium andsaturated fat. A 17-gram (one slice) serving of cheddar cheese contains about 4 grams (0.14 oz) of protein and 120 milligrams of calcium.[54] Nutritionally, cheese is essentially concentrated milk, but altered by the culturing and aging processes: it takes about 200 grams (7.1 oz) of milk to provide that much protein, and 150 grams (5.3 oz) to equal the calcium.[citation needed]
A number of food safety agencies around the world have warned of the risks of raw-milk cheeses. The U.S.Food and Drug Administration states that soft raw-milk cheeses can cause "serious infectious diseases includinglisteriosis,brucellosis,salmonellosis andtuberculosis".[59] It is U.S. law since 1944 that all raw-milk cheeses (including imports since 1951) must be aged at least 60 days. Australia has a wide ban on raw-milk cheeses as well, though in recent years exceptions have been made for SwissGruyère,Emmental andSbrinz, and for FrenchRoquefort.[60] There is a trend for cheeses to be pasteurized even when not required by law.
Pregnant women may face an additional risk from cheese: the U.S.Centers for Disease Control has warned pregnant women against eating soft-ripened cheeses and blue-veined cheeses, due to thelisteria risk, which can cause miscarriage or harm the fetus.[61]
Among the few cheeses in Southeast andEast Asian cuisines ispaneer, a fresh acid-set cheese.[62] InNepal, the Dairy Development Corporation commercially manufactures cheese made fromyak milk and a hard cheese made from either cow or yak milk known aschhurpi.[63]Bhutan produces a similar cheese calledDatshi, which is a staple in most Bhutanese curries.[64] The national dish ofBhutan,ema datshi, is made from homemade yak ormare milk cheese and hot peppers.[65] InYunnan, China, several ethnic minority groups produceRushan andRubing from cow's milk.[66] Cheese consumption may be increasing in China, with annual sales doubling from 1996 to 2003 (to a still small 30 millionU.S. dollars a year).[67]
Strict followers of the dietary laws ofIslam and Judaism must avoid cheeses made withrennet from animals not slaughtered in accordance withhalal orkosher laws respectively.[68]
Rennet derived from animal slaughter, and thus cheese made with animal-derived rennet, is not vegetarian. Most widely available vegetarian cheeses are made using rennet produced by fermentation of the fungusMucor miehei.[69]Vegans and other dairy-avoiding vegetarians do not eat conventional cheese, but somevegetable-based cheese substitutes (soy oralmond) are used as substitutes.[69]
Odorous cheeses
Even in cultures with long cheese traditions, consumers may perceive some cheeses that are especially pungent-smelling, ormold-bearing varieties such asLimburger orRoquefort, as unpalatable. Such cheeses are anacquired taste because they are processed using molds ormicrobiological cultures,[70] allowing odor and flavor molecules to resemble those in rotten foods. One author stated: "An aversion to the odor of decay has the obvious biological value of steering us away from possible food poisoning, so it is no wonder that an animal food that gives off whiffs of shoes and soil and the stable takes some getting used to".[49]
Effect on sleep
There is some support from studies that dairy products can help with insomnia.[71] Scientists have debated how cheese might affect sleep. A folk belief that cheese eaten close to bedtime can cause nightmares may have arisen from the Charles Dickens novellaA Christmas Carol, in which Ebenezer Scrooge attributes his visions of Jacob Marley to the cheese he ate.[72] This belief can also be found in folklore that predates this story.[73] The theory has been disproven multiple times, although night cheese may cause vivid dreams or otherwise disrupt sleep due to its high saturated fat content, according to studies by the British Cheese Board. Other studies indicate it may actually make people dream less.[72][74]
^Papademas, Photis; Bintsis, Thomas (2017).Global Cheesemaking Technology: Cheese Quality and Characteristics.John Wiley & Sons. p. 190.ISBN9781119046172.Archived from the original on February 17, 2023. RetrievedFebruary 1, 2023.The production of [Swiss] cheese was mentioned for the first time in the first century by Roman historian Pliny the Elder, who called the cheeseCaseus Helveticus, the 'cheese of the Helvetians', one of the tribes living in Switzerland at the time.
^"History of Cheese".traditionalfrenchfood.com.Archived from the original on January 12, 2012. RetrievedOctober 21, 2011.
^McGee, Harold (2004).On Food and Cooking (Revised ed.).Scribner. p. 54.ISBN0-684-80001-2.In the United States, the market for process cheese [...] is now larger than the market for 'natural' cheese, which itself is almost exclusively factory-made.
^Quoted inNewsweek, October 1, 1962, according toThe Columbia Dictionary of Quotations (Columbia University Press, 1993ISBN0-231-07194-9, p. 345). Numbers besides 246 are often cited in very similar quotes; whether these are misquotes or whether de Gaulle repeated the same quote with different numbers is unclear.
^"Food Fact Sheet - Cholesterol"(PDF). Association of UK Dietitians. December 1, 2018.Archived(PDF) from the original on February 1, 2012. RetrievedJuly 28, 2019.
