Cheese
Cheese is a dairy food produced from the coagulation and subsequent draining of milk, cream, skimmed milk, or partly skimmed milk, or combinations thereof, using suitable coagulants such as rennet or acid, resulting in a fresh or matured solid product.[1] This process transforms liquid milk into a versatile food with diverse textures, flavors, and uses, ranging from fresh and soft varieties to aged and hard ones.[2] The origins of cheese-making date back to the Neolithic period, with evidence of milk-fat residues in pottery from western Anatolia around the 7th millennium BCE and specialized ceramic sieves used for draining curds in Europe by 5500–5000 BCE.[3] Early cheeses were likely soft, acid-coagulated products made from the milk of domesticated sheep and goats in the Fertile Crescent, developed as a way to preserve dairy for lactose-intolerant adults.[3] By the 4th millennium BCE, proto-cuneiform tablets from Mesopotamia provide the first written records of cheese, and the practice spread with ancient civilizations, including Sumerians, Egyptians, Greeks, and Romans, who refined techniques and documented over 100 varieties.[3] In medieval Europe, monks advanced cheesemaking, preserving knowledge through monasteries, while the first commercial U.S. cheese factory opened in 1851 in New York, marking the shift to industrialized production.[4] Today, cheese production consumes over one-third of U.S. milk supply, with natural cheese output exceeding 6 billion pounds annually since the 1990s.[4] Cheese production begins with milk collection and preparation, often involving pasteurization to reduce pathogens, followed by the addition of starter cultures and coagulants to form curds.[2] The curds are then cut, cooked, and drained to separate whey, after which salting—either dry or in brine—preserves the product and develops flavor.[2] The cheese is pressed into forms and aged under controlled conditions, with duration and environment varying by type; for instance, raw-milk cheeses require at least 60 days of aging at or above 2°C to ensure safety.[2] Variations in milk type (cow, goat, sheep), coagulation method, temperature, and ripening introduce diversity: mesophilic cultures suit softer cheeses, while thermophilic ones yield harder varieties, and surface molds like Penicillium candidum create bloomy-rind types such as Camembert.[2] There are over 1,000 known cheese varieties worldwide, broadly categorized into eight main types based on texture, moisture, and production method.[5] Blue cheeses, like Gorgonzola (originating in Italy's Po Valley around 879 CE), feature veins from Penicillium molds and a pungent flavor.[4] Hard cheeses, such as Parmesan, are low-moisture and aged for grating. Pasta filata types, including mozzarella, are stretched in hot water for elasticity. Processed cheeses are emulsified blends that melt smoothly. Semi-hard varieties like cheddar (ranging from mild creamy to sharp crumbly) balance firmness and flavor. Semi-soft options, such as Havarti, offer spreadable texture. Soft and fresh cheeses, like ricotta or cottage, are unaged and moist. Soft-ripened cheeses, including Brie, develop a runny interior under edible rinds.[5] Nutritionally, cheese is dense in high-quality protein (about 8 grams per ounce of hard cheese), calcium (180 mg per ounce for bone health), and vitamins like B12 and A, while also providing probiotics in fermented varieties that may support gut and heart health.[6] However, it is calorie-rich (around 120 calories per ounce of hard cheese) with high saturated fat (6 grams per ounce) and sodium (180–450 mg per serving), potentially raising risks for cardiovascular disease and hypertension if consumed excessively.[6] Despite these concerns, moderate intake—such as replacing red meat—has been linked to lower stroke risk and no weight gain in some studies.[6] Globally, cheese holds cultural significance in cuisines from French charcuterie to Italian pasta, with annual per capita consumption in the U.S. exceeding 40 pounds.[4]Overview
Definition and characteristics
Cheese is a dairy product produced by coagulating the proteins in milk—primarily casein—and processing the resulting curds through partial whey drainage and optional treatments such as salting, ripening, or flavoring, excluding any non-dairy analogs or plant-based imitations.[7] This process transforms liquid milk into a solid or semi-solid form suitable for direct consumption or further culinary use, with the whey protein-to-casein ratio not exceeding that of the original milk.[7] Key characteristics of cheese include diverse textures ranging from soft and spreadable, as in fresh cheeses like ricotta, to firm and crumbly in aged varieties like Parmesan, largely determined by moisture content and maturation duration.[8] Flavor profiles vary widely from mild and creamy in young cheeses to pungent and complex in ripened ones, arising from microbial fermentation, enzymatic breakdown, and the addition of elements like herbs or molds.[9] Colors span natural whites from uncolored milk to pale yellows or oranges, often enhanced by natural colorants such as annatto derived from achiote seeds.[9] Shelf life is influenced by factors like water activity, pH, salt concentration, and packaging; soft, high-moisture cheeses typically last days to weeks under refrigeration, while low-moisture hard cheeses can endure months or years due to reduced microbial growth.[10] In terms of basic composition, cheese consists primarily of fat (typically 20–40% by weight), protein (20–30%, mostly casein), water (30–60%), and minerals including calcium (often 600–1,000 mg per 100 g), with variations across types reflecting the source milk and processing methods.[11] These components contribute to cheese's nutrient density and versatility. Historically, cheese served as an effective preservation method for milk, concentrating its proteins and fats into a stable form that extended usability beyond seasonal production cycles.[12]Etymology
The English word "cheese" derives from Old English cēse, which meant "curd of milk used as food," stemming from Proto-Germanic kāsijaz and ultimately borrowed from Latin caseus, the classical term for cheese.[13] This Latin root traces further to the Proto-Indo-European kwat-, signifying "to ferment" or "become sour," reflecting cheese's process as a fermented dairy product.[13] Cognates appear in other Germanic languages, such as Dutch kaas and German Käse, all sharing this Latin and pre-Indo-European lineage.[14] In Romance languages, terminology diverges based on regional linguistic evolutions from Latin. French fromage originates from Old French fromage, derived from Vulgar Latin formāticum, meaning "that which is formed," referring to cheese shaped in molds, distinct from the direct caseus borrowing.[15] Similarly, Italian formaggio comes from Late Latin formaticum, emphasizing the molding process in cheese production, while Spanish queso preserves a closer form to Latin caseus, entering via Old Spanish qeso.[16][17] Historical shifts in terminology often aligned with regional dairy practices, particularly for fresh, unaged varieties. For instance, the term "quark," used in Germanic dialects for a soft, fresh cheese curd, derives from Late Middle High German quarc or twarc, borrowed from West Slavic languages like Polish twaróg, denoting "curd" or "that which is formed," and gained prominence in Central European traditions for minimally processed dairy.[18]History
Origins in ancient civilizations
Cheese production is thought to have originated in the Middle East following the domestication of sheep and goats around 8000 BCE, likely through an accidental process where milk stored in animal stomach containers coagulated due to natural rennet enzymes.[19] The earliest archaeological evidence dates to the seventh millennium BCE, with milk fat residues in pottery from Anatolia.[20] This serendipitous discovery would have provided a method to preserve milk solids in a region where nomadic herding practices were developing, transforming perishable liquids into a more stable food source.[21] Archaeological analysis of lipid residues in pottery sieves from the Kujawy region of Poland, dating to approximately 7000 years ago during the Linear Pottery culture (circa 5500–5000 BCE), reveals the earliest direct evidence of cheese-making in Europe, indicating the straining of curds from whey to produce a dairy product.[22] Similar residues in Neolithic pottery from sites in Sweden further support the widespread adoption of these techniques in northern Europe by the mid-sixth millennium BCE, suggesting cheese served as a key dietary staple for early agricultural communities.[23] In Mesopotamia, cuneiform texts from the Third Dynasty of Ur (early second millennium BCE) document cheese as a traded commodity, highlighting its role in economic exchange and food preservation amid the region's arid climate.[24] Egyptian tomb paintings from around 2000 BCE depict cheese production processes, including milking and curd formation, underscoring its cultural significance as an offering for the afterlife and a means of extending dairy shelf life.[25] In Anatolia, clay tablets from the Kültepe site (circa 2000 BCE), an Assyrian trading post, reference a specific cheese variety ("Kültepe peyniri") involved in long-distance commerce, while earlier milk fat residues in seventh-millennium BCE pottery indicate the region's pioneering role in dairying innovations for storage and barter.[26][20]Classical antiquity
In ancient Greece, cheese was a staple food documented in early literature, with Homer describing fresh cheeses in the Iliad around 800 BCE, portraying them as simple, soft varieties made from sheep or goat milk, often consumed soon after production. These depictions highlight cheese as part of everyday pastoral life, pressed in baskets and seasoned minimally. Aristotle, in the 4th century BCE, further advanced understanding by noting the coagulation process, observing that milk could be curdled using extracts from figs or other plants, such as in Phrygian cheese production, which demonstrated early experimentation with vegetal rennet alternatives to animal sources.[27][28] The Romans built upon Greek knowledge, refining cheese production into a more systematic craft as detailed by Columella in his De Re Rustica (1st century CE), where he outlines coagulation using rennet extracted from the stomachs of lambs or kids, emphasizing the importance of warm milk and gentle heating to form curds without direct flame contact. Columella also describes pressing the curds in molds, salting for preservation, and distinguishing between fresh cheeses eaten soon after making and harder varieties ripened for longer storage, including the use of thistle or silphium for vegetal coagulation in some cases. A notable Roman innovation was the development of caseus formatus, or molded cheese, referring to hard, shaped wheels suitable for transport and aging, which marked a shift toward durable products.[29][30] Roman cheese trade flourished across the empire, with hard varieties exported from provinces like Narbonnese Gaul and the Alps to supply urban markets in Italy, as noted by Pliny the Elder in his Natural History (77 CE), who praised the superior quality of Gallic cheeses and described imports such as the Docleatian from Dalmatia and Vatusican from the Centronian Alps. These durable hard cheeses were integral to military rations, providing portable, long-lasting nutrition for legions, with examples like early forms of Pecorino Romano issued to soldiers for campaigns.[31][32]Medieval and Renaissance Europe
During the Middle Ages, cheese production in Europe evolved significantly through the efforts of monastic communities, particularly those of the Benedictine and Cistercian orders, who preserved and refined techniques inherited from ancient Roman traditions. These monks, bound by rules emphasizing manual labor, established dairies within abbeys across France and Italy, experimenting with coagulation, salting, and aging methods to create durable, flavorful varieties suitable for long storage and trade. For instance, Benedictine monks in the Parma and Reggio Emilia regions of Italy began producing hard, grated cheeses known as caseus parmensis as early as the 12th century, laying the groundwork for what would become Parmigiano-Reggiano.[33] Similarly, Cistercian abbeys in France developed semi-soft washed-rind cheeses, such as precursors to modern Époisses and Maroilles, using local cow's milk and brine washes to enhance flavor and preservation.[34] Trade networks expanded the reach of these monastic innovations, transforming cheese from a local staple into a commodity of economic importance. The Hanseatic League, a powerful confederation of merchant guilds in northern Europe, played a key role in distributing Dutch cheeses from the Low Countries starting in the late 13th century. In the Netherlands, particularly around Edam, farmers produced compact, ball-shaped cheeses coated in wax for easy transport by sea, which the League's ships carried to Baltic ports and beyond, fostering standardization in production to meet distant markets' demands.[35] This commerce not only boosted regional economies but also encouraged refinements in cheese shapes and packaging to withstand long voyages.[36] In the Renaissance period, particularly from the 14th to 16th centuries, Italian cheesemakers formalized quality standards amid growing urban demand and cultural appreciation for refined foods. In 1348, regulations in the Duchy of Parma and Reggio Emilia restricted Parmigiano-Reggiano production to specific geographic areas and monastic-supervised methods, ensuring consistency in milk sourcing, rennet use, and minimum aging periods of up to two years, which distinguished it from lesser imitations.[37] The invention of the printing press further accelerated these advancements by disseminating recipes and techniques through early cookbooks; Bartolomeo Platina's De Honesta Voluptate (1474), the first printed book on culinary arts, included detailed instructions for incorporating aged cheeses like Parmigiano into dishes, influencing chefs across Europe and promoting artisanal standards.[38]Industrialization and modern developments
The industrialization of cheese production began in the mid-19th century, marking a shift from small-scale, farm-based cheesemaking to centralized factory systems. In 1851, Jesse Williams, a dairy farmer in Rome, New York, established the world's first cheese factory, where he processed milk from multiple neighboring farms into standardized Cheddar cheese using a systematic approach that included mechanized stirring and pressing. This innovation, often called the "factory system," dramatically increased efficiency and output, enabling the production of up to 25,000 pounds of cheese annually from a single operation and laying the foundation for the modern dairy industry in the United States. By the 1860s, Louis Pasteur's invention of pasteurization—a heat treatment process to eliminate harmful microorganisms—began influencing dairy practices, though its widespread application to milk for cheesemaking occurred later, around the early 1900s, improving safety and consistency in industrial production. The 20th century saw further advancements in mass production techniques, transforming cheese into a globally traded commodity. In 1911, Swiss inventors Walter Gerber and Fritz Stettler developed the first processed cheese by melting and emulsifying natural cheeses with stabilizers, extending shelf life and uniformity for commercial distribution; James L. Kraft refined and patented a similar process in 1916, leading to the launch of Kraft's canned processed cheese in 1917, which became a staple for its meltability and portability. During World War II, rationing in countries like the United States and United Kingdom profoundly impacted cheese production: in the U.S., cheese was limited to 4 ounces per person weekly from 1943 to 1945, spurring demand for durable processed varieties and boosting exports of government-standardized Cheddar to Allied forces; in the UK, rationing from 1941 to 1954 restricted production to a single "government Cheddar" type, prioritizing efficiency for wartime needs and nearly eradicating diverse farmhouse cheeses. In the 21st century, cheese production has experienced a dual trajectory of technological innovation and cultural revival amid growing globalization. An artisanal movement, building on 1970s roots in the U.S. and Europe, has surged since the 2000s, with small-scale producers emphasizing traditional methods, raw milk, and regional terroirs; by the 2010s, the U.S. alone saw over 1,000 artisan cheesemakers, reviving varieties like farmhouse Cheddar and fostering a market for premium, handcrafted products. Concurrently, plant-based cheese alternatives have proliferated post-2010, driven by veganism and sustainability concerns, with nut- and oat-based options from brands like Miyoko's Creamery (founded 2014) and Kite Hill achieving improved texture and flavor through fermentation techniques, capturing a growing segment of the dairy-free market. Global cheese production reached approximately 23.8 million metric tons in 2023, reflecting steady demand growth fueled by population increases and exports, particularly from leading producers like the European Union and the United States.Production
Milk selection and preparation
The production of cheese begins with the careful selection of milk, which serves as the foundational ingredient determining the final product's quality, yield, and flavor profile. Globally, cow's milk is the primary source for cheese production, as it constitutes approximately 83% of the world's milk output due to its abundance and suitability for large-scale processing. Breeds such as Holstein are preferred for their high milk yield, producing up to 10,000 liters per lactation cycle, though this comes at the expense of lower fat content compared to breeds like Jersey. Other sources include sheep's milk (about 1.3% of global milk production), goat's milk (2.3%), and buffalo's milk (13.3%), each imparting distinct flavors—such as the tangy notes from goat milk or the creamy richness from buffalo milk—often used in artisanal or regional varieties like Roquefort or mozzarella.[39][40][41] Quality criteria for milk in cheesemaking emphasize compositional balance and hygiene to ensure consistent coagulation and minimize defects. Fat content typically ranges from 3% to 5% by weight, with an average of around 3.9% in Holstein-derived milk, directly influencing cheese texture and yield—higher fat levels promote softer, richer cheeses. Bacterial load must be controlled, with total plate counts ideally below 3,000 colony-forming units (CFU) per milliliter for good quality to support beneficial fermentation without risking spoilage or off-flavors. Seasonal variations further affect quality, as spring and summer milk from pasture-fed animals tends to have higher beta-carotene and conjugated linoleic acid content, contributing to more complex, grassy flavors in the resulting cheese, while winter milk may be denser but less vibrant due to supplemental feeds.[41][42][43][44] Preparation of selected milk involves several steps to standardize its composition for reliable cheese outcomes. Standardization adjusts the fat-to-protein ratio, typically targeting 0.70 to 1.15 depending on cheese type—for instance, a ratio of about 0.91 for Cheddar—to optimize curd firmness and recovery rates, achieved by separating cream via centrifugation and recombining it with skim milk or by adding protein concentrates like milk protein concentrate. Filtration removes physical impurities and somatic cells, using microfilters with 10- to 14-micron pores to clarify the milk without altering its chemistry, thereby reducing the risk of bitterness or uneven ripening. Milk is typically pasteurized by heating to 72°C for 15 seconds (high-temperature short-time method) or equivalent to eliminate pathogenic bacteria, although raw milk is permitted for certain traditional varieties with minimum aging periods to ensure safety. Optionally, milk may be fortified with starter cultures—lactic acid bacteria such as Lactococcus lactis—early in preparation to initiate controlled acidification, enhancing flavor development and consistency, particularly in pasteurized milk where natural microbiota are diminished.[45][46][47][48][49][2]Coagulation and curd formation
Coagulation is the critical step in cheesemaking where liquid milk transforms into a semisolid curd through the destabilization of casein micelles, the primary protein structures in milk that normally remain suspended in colloidal form.[50] This process involves the formation of a gel network that entraps fat globules and water, setting the foundation for cheese structure.[51] The method of coagulation varies depending on the cheese type, but all rely on disrupting the electrostatic and steric stabilization of casein micelles to induce aggregation.[52] The primary coagulation methods include acid, enzymatic, and heat-based approaches. In acid coagulation, direct addition of acids such as vinegar or citric acid lowers the milk's pH to approximately 4.6, neutralizing the negative charge on casein micelles and causing them to aggregate into a fragile curd; this technique is commonly used for fresh cheeses like paneer. Enzymatic coagulation employs rennet, an enzyme extract primarily containing chymosin, which specifically hydrolyzes the kappa-casein protein on micelle surfaces, removing hydrophilic glycomacropeptides and exposing hydrophobic regions that promote rapid micelle fusion into a firm gel; this is the standard for aged varieties like cheddar. Heat coagulation, often combined with mild acidification, involves heating milk or whey to 80–90°C at pH 5.6–6.0, denaturing whey proteins and facilitating casein precipitation without enzymes; ricotta exemplifies this method, yielding a soft, granular curd.[53] At the chemical level, casein micelles—spherical aggregates of alpha-, beta-, and kappa-caseins stabilized by colloidal calcium phosphate and kappa-casein's extended hydrophilic chains—are destabilized to form the curd. In enzymatic action, chymosin cleaves the Phe105-Met106 bond in kappa-casein, reducing surface charge and steric hindrance, which initiates primary phase aggregation followed by secondary gelation as micelles form a three-dimensional network trapping fat and water.[50] Acid coagulation protonates casein surfaces, collapsing the micelle structure by minimizing electrostatic repulsion and releasing bound calcium, leading to a coarser gel compared to enzymatic methods.[52] Heat-assisted processes enhance this by partially unfolding proteins, promoting hydrophobic interactions and cross-linking that strengthen the network under acidic conditions.[51] Curd firmness, which determines the cheese's final texture and yield, is influenced by several key factors including temperature, pH, and coagulant dosage. Optimal temperatures of 30–40°C accelerate enzymatic reactions and micelle aggregation without denaturing proteins, yielding firmer curds; deviations can extend coagulation time or weaken the gel. A controlled pH drop to 4.6–5.2 during acid methods or to around 6.3–6.5 post-rennet addition optimizes charge neutralization and calcium solubility, preventing overly soft or brittle curds.[54] Coagulant dosage must be precisely calibrated—typically 20–40 mL of rennet per 1000 L of milk—to achieve coagulation within 30–45 minutes, as excess can cause premature firming and fat loss, while insufficient amounts prolong the process and reduce yield.[55] These parameters interact synergistically, with post-preparation adjustments ensuring consistent curd quality across batches.[56]Whey separation and pressing
After coagulation, the curd undergoes syneresis, a process where the gel network contracts and expels liquid whey, concentrating the solids to form the basis of the cheese mass.[57] This contraction is primarily induced by cutting the coagulum into small pieces, which increases the surface area and disrupts the protein matrix, allowing whey to drain more readily.[58] Stirring the curds further promotes syneresis by maintaining even distribution of heat and agitation, preventing matting and facilitating the release of up to 90% of the whey in hard cheese varieties.[57] Factors such as temperature, pH, and milk composition influence the rate of syneresis, with higher temperatures and lower pH accelerating whey expulsion.[58] Once syneresis has progressed sufficiently, the curds are typically drained to separate the remaining whey. This is commonly achieved by transferring the curd mass into cheesecloth or a muslin-lined colander, where gravity assists in draining the liquid over several minutes to hours, depending on the cheese type.[59] For softer cheeses like queso fresco, gentle twisting of the cheesecloth squeezes out excess whey without additional mechanical aid.[59] The resulting curd is a loose, semi-solid mass ready for further processing, with the separated whey serving as a byproduct that can be used to produce secondary cheeses like ricotta or as nutritional animal feed.[60][61] Pressing follows draining to consolidate the curds and expel any residual whey, forming a cohesive cheese wheel or block. For soft cheeses, such as Neufchâtel, light hand-pressing with weights applied via cheesecloth in perforated molds for 2–4 hours suffices to achieve the desired texture.[59] Hard cheeses require more intensive mechanical pressing in specialized molds, where pressures gradually increase to knit the curds together; for example, experimental production of low-fat varieties has used up to 60 psi over extended periods.[62] In the case of Gouda, a semi-hard cheese, pressing typically begins at low pressures around 2–4 psi and builds to ensure even whey removal without cracking the rind.[63] Overall cheese yield from this stage is approximately 1 kg per 10 liters of milk, reflecting the concentration of milk solids after whey removal.[64]Salting and shaping
After the whey is separated and the curds are pressed, salting is applied to preserve the cheese, enhance its flavor, and control moisture levels. Salt functions primarily as a preservative by reducing water activity, which inhibits the growth of spoilage bacteria and pathogens while favoring salt-tolerant beneficial microorganisms.[65] It also draws out excess moisture from the curds through syneresis, aiding in texture development and preventing over-hydration during subsequent stages.[66] Additionally, salt directly contributes to the cheese's flavor profile by modulating enzymatic activities and aroma compounds.[67] The final salt content in most cheeses ranges from 1% to 3% by weight, though it varies by type, with lower levels in Swiss-style cheeses (~0.7%) and higher in brined varieties up to 5%.[68] Salting methods differ based on cheese variety and desired outcomes. Dry salting involves mixing salt directly into the curds, often after milling, as in Cheddar production where milled curd pieces (approximately 7 × 1.2 × 1 cm) are tumbled with 2–3% salt by weight for 10–30 minutes before pressing; this ensures even distribution and rapid uptake.[69] Brine immersion, used for semi-soft and fresh cheeses like Feta and Gouda, submerges molded curds in a saturated salt solution (18–25% NaCl) at 8–20°C for 0.5–8 days, allowing gradual diffusion while expelling whey and achieving uniform salting.[69] For Feta specifically, the brine concentration is typically around 18%, which supports its characteristic tangy preservation during ripening.[69] Surface dry salting or rubbing applies salt directly to the exterior of molded cheeses, such as certain blue varieties, to create a protective rind.[70] Following salting, the curds are shaped into their final forms using molds that define the cheese's size, weight, and appearance. Common shapes include cylindrical wheels for aging varieties like Gouda or Brie, which promote even rind development and moisture distribution; for example, traditional Brie wheels measure about 30 cm in diameter and 3–5 cm in height, weighing 2–3 kg.[71] Molds are often perforated to allow whey drainage during pressing, and the shaped cheeses may be flipped periodically to ensure uniformity. Once firm, the rind is typically stamped with marks indicating origin, producer, and production date, as seen in protected designation cheeses like Parmigiano-Reggiano, where stenciled bands imprint "marks of origin" around the wheel shortly after molding to verify authenticity.[72] This stamping not only aids traceability but also helps distinguish genuine products in regulated varieties.[73]Processing and ripening
Initial processing techniques
After whey separation and initial pressing, the curd is subjected to cutting and milling to refine its structure and influence the final cheese texture. The curd is typically cut into grains ranging from 1 to 15 mm using knives or automated cutters, with smaller sizes—around 3-5 mm—employed for hard cheeses to enhance whey expulsion and yield a denser, firmer product, while larger cuts retain more moisture for softer varieties.[74] In specific varieties like Cheddar, the cheddaring process follows, where drained curd is stacked into slabs or blocks about 15 cm high and turned every 15 minutes to promote further acidification and realign the casein proteins, continuing until the pH drops to approximately 5.3 before milling into finer chips.[75][59] Surface treatments are then applied to the pressed cheese forms to safeguard the exterior and facilitate handling prior to ripening. Brushing gently removes surface debris or excess mold from the developing rind, waxing seals the surface to minimize moisture loss and microbial ingress, and banding—often with cloth wraps—is utilized for traditional styles to support shape integrity and rind protection during storage and transport.[74] Throughout these stages, rigorous quality checks ensure consistency, including pH monitoring to achieve a target of 5.0–5.5 for optimal microbial stability and texture development, alongside moisture control to 35–50% via pressing adjustments, which directly impacts the cheese's firmness and shelf life.[74]Ripening processes
Ripening is the transformative phase in cheese production where biochemical reactions convert the fresh curd into a mature product with developed flavor, aroma, and texture. This process involves the coordinated action of enzymes and microorganisms, leading to the degradation of major milk components like proteins, fats, and residual carbohydrates.[76] The ripening process unfolds in distinct stages, beginning with primary changes focused on acidification. During this initial phase, lactic acid bacteria (LAB), such as Lactococcus lactis, rapidly ferment any residual lactose—typically 0.8–1.0% in varieties like Cheddar—into lactic acid, which lowers the pH and stabilizes the curd structure. This acidification, often completed within the first few days, sets the foundation for subsequent developments by influencing moisture retention and microbial succession.[76][77] Secondary ripening follows, spanning weeks to months, where intricate flavor profiles emerge through catabolic reactions. Non-starter LAB and secondary microorganisms further metabolize lactate and other substrates, producing volatile compounds that define the cheese's sensory qualities. This extended phase varies by cheese type, with hard varieties like Parmesan requiring up to two years for optimal complexity.[76][77] Central to these transformations are enzymatic actions, particularly proteolysis and lipolysis. Proteolysis entails the hydrolysis of caseins by residual rennet (chymosin), which cleaves αs1-casein at the Phe23-Phe24 bond and β-casein at multiple sites, alongside plasmin from milk and peptidases from LAB. These enzymes break down proteins into peptides and free amino acids, which act as precursors for savory and bitter notes while softening the texture. Up to 30% of chymosin may remain active post-coagulation, driving ongoing degradation.[76] Lipolysis complements this by liberating free fatty acids from milk fat globule triglycerides via lipases, including lipoprotein lipase from milk, pregastric esterase in some rennets, and microbial sources. The resulting short- and medium-chain fatty acids, such as butyric and caproic acids, impart sharp, pungent flavors, with levels notably elevated in aged hard cheeses and blue varieties.[76][77] Microbial communities play pivotal roles throughout ripening, with LAB dominating the primary stage by converting lactose to L(+)-lactate and later racemizing it to D(-)-lactate via non-starter LAB. In specialized cheeses, molds like Penicillium roqueforti in blue varieties enhance lipolysis and metabolize free fatty acids into methyl ketones, such as heptan-2-one, responsible for the characteristic spicy, blue-veined aroma. Similarly, Penicillium camemberti on soft-ripened surfaces deacidifies the rind, promoting proteolysis and earthy flavors. These interactions underscore how starter and adjunct cultures tailor ripening outcomes.[76][77]Aging environments
The aging environment plays a critical role in cheese maturation, providing the controlled physical conditions that influence microbial activity, moisture retention, and flavor development during ripening. These environments must maintain stable temperature and humidity to prevent undesirable drying, cracking, or excessive mold growth, while allowing biochemical processes to proceed optimally.[78] Temperature and relative humidity vary by cheese type to suit their texture and ripening needs. Hard cheeses, such as Parmesan, are typically aged at warmer temperatures around 18°C with 80–85% humidity to facilitate slow proteolysis and flavor intensification without rapid moisture loss. In contrast, softer or semi-soft varieties like Camembert require slightly cooler conditions of 12–16°C and higher humidity of 92–98% to support surface mold development and prevent rind desiccation. Overall, most cheeses benefit from 80–95% relative humidity to minimize weight loss, with hard types often at the lower end (80–90%) and bloomy-rind types at the higher end (90–95%).[79][80][78] Traditional and modern facilities are designed to replicate or enhance these conditions. Natural caves, such as the Combalou caves used for Roquefort, provide inherent stability with temperatures of 8–15°C and 85–98% humidity, fostering the growth of Penicillium roqueforti for blue veining. Controlled cellars or aging rooms in artisanal settings use insulated structures with glycol cooling systems to maintain precise parameters, often requiring regular turning of wheels for even exposure. Industrial factories employ advanced setups with sensors for monitoring temperature, humidity, airflow, and carbon dioxide levels—emitted by ripening microbes—to ensure consistent quality and prevent off-flavors from anaerobic conditions.[81][82][78] The duration of aging in these environments directly affects the final product's characteristics, with longer periods yielding more complex flavors and firmer textures. For instance, young Gouda ripens for about 2 months at 13–16°C and 80–90% humidity, resulting in a mild, supple cheese, while aged varieties extend to 6–12 months for nuttier notes. Aged Parmesan, conversely, matures for over 2 years—often 24–36 months—in environments of 18°C and 80–85% humidity, developing its granular structure and intense umami through extended enzymatic breakdown.[83][84][79]Types of cheese
Classification by milk source
Cheeses are primarily classified by the source of milk used in their production, which significantly influences their flavor, texture, and nutritional profile due to variations in fat, protein, and mineral content among different animal species.[85] The vast majority of cheese worldwide is made from cow's milk, accounting for approximately 90% of global natural cheese production. Cow's milk cheese is versatile and typically mild in flavor, allowing for a wide range of styles from fresh to aged varieties, such as Cheddar, which exemplifies its adaptability in both industrial and artisanal production. This dominance stems from the high volume of cow milk available globally, comprising about 83% of total milk production.[39][85] Sheep's milk cheeses represent a smaller but distinctive category, produced from milk with higher fat content, typically 6–7%, which contributes to richer, tangier flavors. Examples include Roquefort, a blue-veined cheese with sharp, earthy notes, and Pecorino, a hard grating cheese valued for its salty intensity. Sheep milk constitutes only about 1% of global milk production, limiting these cheeses to more specialized markets.[86][87][39] Goat's milk is used for cheeses that often exhibit tangy and acidic profiles due to its composition, including a predominance of A2 beta-casein, which differs from the A1 variant common in cow's milk and may influence digestibility. With protein levels around 3.6%, goat milk yields cheeses like chèvre, a fresh, soft variety with a bright, citrusy tang. Buffalo milk, though less common, produces creamy cheeses such as Mozzarella di Bufala Campana, leveraging its high fat (about 7.4%) and solids for superior meltability and richness; it accounts for roughly 13% of world milk supply. Although buffalo milk represents about 13–15% of global production, much of it is consumed as fresh milk or in other products, limiting its use in cheese to niche varieties. Goat and sheep milks together make up about 3–4% of global production (as of 2023).[88][41][89] In niche or mixed-milk categories, non-traditional sources like camel and yak milk are employed in specific regions, yielding unique cheeses adapted to local production methods. Camel milk cheese, such as Caravane—a semi-soft variety reminiscent of Camembert—is made in arid areas and features a mild, slightly sweet taste from milk with low lactose (around 4.1%). Yak milk, used in high-altitude Himalayan communities, produces denser cheeses higher in conjugated linoleic acid, offering potential health benefits over cow milk varieties. These represent less than 1% of global output and often involve blending with other milks for consistency.[90][91][39]Classification by texture and moisture
Cheeses are classified by texture and moisture content, which primarily influence their firmness, mouthfeel, and suitability for various uses, with moisture levels ranging from over 50% in fresh varieties to under 35% in aged hard types. This classification emphasizes physical properties resulting from processing rather than milk source or regional origin. Higher moisture contents generally yield softer, more perishable cheeses, while lower levels produce firmer, longer-lasting ones.[92] Soft or fresh cheeses possess high moisture content, typically 50–80% or more, and are unripened, resulting in a spreadable or crumbly texture that is mild and delicate. Examples include ricotta, with around 70% moisture, and cream cheese, which has a maximum of 55% moisture per U.S. standards.[92][93][94] Semi-soft cheeses have moderate moisture levels, generally between 39% and 50%, conferring an elastic, supple texture that is pliable yet sliceable. Havarti exemplifies this category, with approximately 44% moisture, offering a smooth, creamy consistency suitable for melting.[92][93] Hard cheeses feature low moisture content, typically under 39% and often below 35%, achieved through extensive moisture loss during production, leading to a firm, dense texture ideal for grating. Parmesan (Parmigiano-Reggiano), for instance, contains no more than 32% moisture and is aged for at least 12 months to develop its granular structure.[92][95][93] Moisture content in cheese is controlled through pressing to expel whey and ripening processes that allow further evaporation, directly impacting the final texture and firmness. Ripening environments can enhance this effect by promoting controlled drying.[96]Regional and specialty varieties
Cheese production yields over 1,800 distinct varieties worldwide, many protected by designations that tie them to specific regions and traditional methods.[97] In Europe, Protected Designation of Origin (PDO) status safeguards several iconic cheeses, ensuring they are made exclusively within defined geographic areas using local ingredients and techniques. Camembert de Normandie, originating from Normandy in northern France, is a soft, bloomy-rind cheese crafted from raw cow's milk; its PDO was granted in 1983, requiring production in Normandy with milk from grass-fed cows grazing on the region's pastures.[98] Similarly, Manchego from Spain's La Mancha region is a semi-hard cheese made solely from the milk of Manchega sheep, aged between 60 days and two years; it received PDO protection in 1984, emphasizing the arid plateau's thistle-rennet tradition and sheep-herding heritage.[99] Blue Stilton, a crumbly blue-veined variety from England's Midlands counties of Derbyshire, Leicestershire, and Nottinghamshire, uses pasteurized cow's milk inoculated with Penicillium roqueforti for its characteristic veins and tangy flavor; its PDO status, established in 1996, limits production to just seven licensed dairies.[100] Across the Atlantic, American cheeses reflect innovative adaptations suited to industrial-scale production and diverse consumer tastes. Colby, a semi-soft, mild cow's milk cheese with a creamy texture and open texture from washing the curds, was invented in 1885 by Joseph Steinwand at his family's factory in Colby, Wisconsin, as a milder alternative to cheddar.[101] Processed American cheese, known for its uniform meltability and sliceable form, emerged from a patented emulsification process developed by James L. Kraft in 1916, blending natural cheeses with stabilizers to extend shelf life and prevent spoilage—by the 1930s, it accounted for over 40% of U.S. cheese consumption.[102] Specialty cheeses highlight unique flavor profiles achieved through smoking, veining, or alternative bases, often bridging traditional and modern innovations. Scamorza affumicata, a pear-shaped stretched-curd cheese from southern Italy, is made from cow's milk and lightly smoked over wood to impart a golden rind and subtle smoky aroma, distinguishing it from its unsmoked counterpart while maintaining a semi-soft, elastic texture ideal for grilling.[103] Blue-veined cheeses like Stilton exemplify the category's bold, piquant notes from mold cultures, contrasting with smoother regional styles. Emerging post-2020, vegan cashew-based cheeses have gained traction as plant-derived alternatives, using fermented cashews to mimic creamy textures and aged flavors in varieties like soft spreads or rind-wrapped wheels, driven by demand for dairy-free options.[104] These varieties often align with broader classifications by texture—such as soft for Camembert or firm for Manchego—but their regional ties and specialties define their cultural identity.Culinary uses
In cooking and recipes
Cheese plays a pivotal role in global cuisines as a versatile ingredient that enhances flavor, texture, and creaminess in cooked dishes through its ability to melt, bind, and add richness.[105] The melting properties of cheese are influenced by factors such as moisture content, fat level, and protein structure, which determine how it behaves under heat in recipes. Low-moisture varieties like mozzarella are preferred for pizza because they provide an elastic, stretchy melt without excessive oil separation, allowing for even browning and adhesion to toppings.[105][106] In contrast, higher-fat cheeses such as Gruyère, which contains around 30% fat, excel in sauces like Mornay, where they create a smooth, velvety emulsion when incorporated into a béchamel base.[107][108] Common culinary applications leverage these properties for diverse preparations, including grating, baking, and frying. Hard, aged cheeses like Parmesan are often finely grated and sprinkled over pasta dishes, such as cacio e pepe or spaghetti aglio e olio, to provide a sharp, umami finish that integrates without overpowering the sauce.[109] For baked recipes, Emmental's nutty flavor and excellent melting qualities make it ideal for fondue, where it is combined with white wine and cornstarch to form a dip served with bread or vegetables.[110] Halloumi, with its high melting point due to a dense protein matrix, is commonly pan-fried or grilled until golden and crispy, retaining its shape for use in salads, wraps, or as a meat substitute in Mediterranean-inspired meals.[111] Iconic cultural dishes highlight cheese's integration into traditional recipes across regions. Macaroni and cheese became a staple in American cuisine in the 18th century, introduced to the United States by Thomas Jefferson via English and French influences, with early versions featuring a creamy cheese sauce baked over pasta elbows.[112] In Switzerland, raclette involves melting semi-soft cheese over boiled potatoes and accompaniments like pickles, a tradition rooted in Alpine herding practices where the cheese is scraped from the rind after heating.[113] In other regions, fresh cheeses like paneer are used in Indian curries such as palak paneer, adding texture and protein, while queso fresco features in Mexican dishes like tacos for a mild, crumbly contrast.[114]As a table food and pairings
Cheese is commonly enjoyed as a table food, served at room temperature to highlight its flavors and textures, often as a standalone snack or centerpiece of social gatherings like cheeseboards.[115] A typical cheeseboard features an assortment of 3 to 5 cheese varieties to provide a range of textures and intensities, such as soft, semi-soft, and hard options, complemented by fresh and dried fruits like grapes, figs, or apricots for sweetness and contrast, as well as nuts such as almonds or walnuts for crunch.[116][117] Pairing principles emphasize balancing cheese's richness and flavors with beverages; for instance, acidic white wines like Sauvignon Blanc pair well with creamy cheeses such as Brie to cut through the fat, while robust red wines like Cabernet Sauvignon complement hard, aged cheeses like Cheddar with their tannins matching the cheese's intensity.[118][119][120] Beers are also popular accompaniments, particularly with pungent varieties; India Pale Ales (IPAs) or porters stand up to the bold, funky notes of blue cheeses like Gorgonzola, providing a refreshing bitterness.[121] As of 2023, average per capita cheese consumption reached approximately 21.9 kg in the European Union, compared to 18.4 kg (40.5 pounds) in the United States, reflecting its prominence as a table food in both regions.[122][123]Nutrition and health
Nutritional composition
Cheese is a nutrient-dense food, with its nutritional profile varying by type, but typical values per 100 grams provide a substantial source of macronutrients and micronutrients. On average, cheese contains 25–35 grams of total fat, of which 15–20 grams are saturated fats, contributing to its high energy density of 300–400 kilocalories.[124] Protein content is also notable, ranging from 20–25 grams per 100 grams, primarily in the form of high-quality caseins that support muscle maintenance.[124]| Nutrient | Average per 100g | % Daily Value (approx.) |
|---|---|---|
| Calories | 350–400 kcal | 17–20% |
| Total Fat | 25–35 g | 32–45% |
| Saturated Fat | 15–20 g | 75–100% |
| Protein | 20–25 g | 40–50% |
Health benefits and risks
Cheese offers several potential health benefits when incorporated into a balanced diet, primarily through its nutrient profile. Varieties like Swiss and Gouda contain live probiotic cultures that can survive gastrointestinal transit, supporting gut health by modulating the microbiome and promoting beneficial bacteria.[128] These probiotics may also contribute to anti-inflammatory effects and improved immune responses, as evidenced by studies on fermented dairy products.[129] Additionally, cheese is a rich source of calcium, which aids bone health; research shows that calcium from cheese enhances bone mineral density more effectively than supplements in children and adolescents.[130] Grass-fed cheeses provide higher levels of conjugated linoleic acid (CLA), a fatty acid with demonstrated anti-inflammatory properties that may reduce markers of chronic inflammation.[131] Despite these advantages, cheese consumption carries risks, particularly related to its macronutrient composition. It is high in saturated fats, which can elevate low-density lipoprotein (LDL) cholesterol levels, a key risk factor for cardiovascular disease.[132] To minimize this effect, health guidelines recommend moderate intake of around 40 grams per day.[133] Cheese also contains substantial sodium, typically averaging 1 to 1.7 grams per 100 grams in hard varieties, which may increase blood pressure and hypertension risk in salt-sensitive individuals.[134] Scientific evidence on cheese's overall health impact is mixed but often reassuring regarding cardiovascular outcomes. A 2021 systematic review and meta-analysis of prospective cohort studies found inconsistent associations between cheese intake and cardiovascular events, indicating a largely neutral effect despite its saturated fat content.[135] Similarly, an umbrella review of multiple meta-analyses reported moderate-quality evidence linking cheese consumption to reduced risks of cardiovascular disease and mortality, countering traditional concerns.[136] However, individuals with lactose intolerance, which affects 65% to 70% of the global population, may experience digestive discomfort from softer, higher-lactose cheeses, though aged varieties are generally better tolerated.[137]Safety and pasteurization
Pasteurization is a critical food safety process in cheese production that involves heating milk to destroy pathogenic bacteria while preserving its suitability for cheesemaking. The standard high-temperature short-time (HTST) method heats milk to 72°C for 15 seconds, which effectively inactivates pathogens such as Listeria monocytogenes and Salmonella enterica. This treatment minimizes the risk of contamination in the final product, and in the United States, regulations under the Pasteurized Milk Ordinance require pasteurization for most dairy processing, resulting in approximately 99.6% of cheese being made from pasteurized milk. [138] Despite these measures, raw milk cheeses—made without pasteurization—remain available under specific conditions and pose higher risks of harboring pathogens if not properly managed. For instance, a 2019 outbreak in France linked to consumption of raw cow's milk cheeses like Saint-Félicien and Saint-Marcellin resulted in 18 cases of Shiga toxin-producing Escherichia coli (STEC) O26 infections, including pediatric hemolytic uremic syndrome. [139] Regulations vary globally; in the European Union, raw milk is permitted for protected designation of origin (PDO) cheeses provided strict hygiene and microbiological criteria are met, allowing traditional varieties to retain their characteristic flavors. [140] To ensure safety in cheese production, factories implement Hazard Analysis and Critical Control Points (HACCP) standards, a systematic approach mandated by the FDA under the Food Safety Modernization Act for identifying and controlling hazards like microbial contamination at key stages such as milk reception, coagulation, and packaging. [141] Additionally, for raw milk cheeses in the US, federal regulations require aging for at least 60 days at a minimum temperature of 1.7°C (35°F) to allow natural acidification and enzymatic activity to reduce pathogen levels, with FDA surveillance finding less than 1% of such aged cheeses contaminated with targeted pathogens like Salmonella, Listeria monocytogenes, and STEC. However, recent 2025 FDA-backed research indicates that this aging process may not effectively inactivate certain viral pathogens, such as H5N1 avian influenza virus detected in raw milk, highlighting ongoing safety considerations for raw milk cheeses.[142] [143] [144]Cultural and economic aspects
Cultural significance worldwide
Cheese holds a prominent place in European cultural traditions, symbolizing regional identity and national pride. In France, fromage is deeply embedded in the nation's culinary heritage, often referred to as part of the "cuisine nationale," where it represents diversity and terroir-driven excellence, with over 1,200 varieties reflecting the country's varied landscapes and history.[145] French cheese courses, served after the main meal and before dessert, underscore social rituals and the appreciation of raw milk products as emblems of authenticity and resistance to standardization.[146] In Switzerland, cheese extends beyond cuisine into diplomatic practices; for instance, raclette is employed in official gatherings to promote unity and hospitality, as noted by Swiss Ambassador Pascale Baeriswyl, who uses it to melt barriers among international diplomats during shared meals.[147] This reflects cheese's broader role in Swiss traditions, where varieties like Gruyère and Emmentaler embody communal alpine herding customs and national heritage.[148] Outside Europe, cheese variants integrate into non-Western dietary and social frameworks, particularly in vegetarian-centric cultures. In India, paneer—a fresh, unaged cheese made from curdled milk—serves as a cornerstone of vegetarian diets, providing essential protein and fat for roughly 30% of the population adhering to such practices, and features prominently in festive dishes like saag paneer during communal celebrations.[149] Its origins trace to ancient innovations that aligned with Vedic purity norms, evolving into a symbol of adaptability in meat-restricted Hindu traditions.[150] In Mongolia, dairy traditions revolve around airag, a fermented mare's milk beverage that is lightly alcoholic, which holds national pride as a nomadic staple produced through communal fermentation rituals, sustaining herders during long migrations and marking seasonal festivals.[151] Accompanying airag, hardened cheeses like aaruul further emphasize preservation techniques vital to steppe survival.[152] Cheese festivals worldwide celebrate these traditions through communal events that blend history, performance, and commerce. In the United States, Wisconsin Cheese Days in Monroe, held biennially since 1938, honors Swiss immigrant influences with parades, yodeling, and cheese-carving contests, drawing thousands to affirm the state's "America's Dairyland" moniker.[153] Similarly, the Alkmaar Cheese Market in the Netherlands, dating to 1593, reenacts medieval trading rituals with hand-clapping negotiations and wheel-carrying demonstrations, preserving Dutch mercantile heritage as a UNESCO-recognized intangible cultural practice.[154] Artistically, cheese symbolizes abundance and transience in Dutch Golden Age still lifes, such as Clara Peeters' Still Life with Cheeses, Almonds, and Pretzels (c. 1615), where stacked wheels denote prosperity and the fleeting nature of wealth amid the era's economic boom.[155] These paintings, including Floris van Dijck's works, elevated cheese as a marker of affluence and national pride in 17th-century Netherlands.[156]Production and consumption trends
Global cheese production reached 22.35 million metric tons in the 2023/2024 marketing year, marking a 2.2% increase from the previous year, driven primarily by expansions in Europe and North America.[157] The European Union remains the dominant producer, accounting for about 47% of global output with 10.7 million metric tons in the 2024/2025 marketing year, followed by the United States at 29% or 6.46 million metric tons. For 2025, EU production is projected at 10.8 million metric tons, a 0.6% increase from 2024.[158] Other notable producers include Russia at 1.16 million metric tons (5%) and Brazil at 775,000 metric tons (3%), reflecting a concentration of production in established dairy regions while emerging markets contribute modestly.[157]| Rank | Country/Region | Production (2024/2025, million metric tons) | Share of Global (%) |
|---|---|---|---|
| 1 | European Union | 10.7 | 47 |
| 2 | United States | 6.46 | 29 |
| 3 | Russia | 1.16 | 5 |
| 4 | Brazil | 0.775 | 3 |