() is a technique in the manufacture of a family of Italian cheeses also known in English as stretched-curd, pulled-curd, and plastic-curd cheeses. Stretched curd cheeses manufactured using the technique undergo a plasticising and kneading treatment of the fresh curd in hot water, which gives the cheese its fibrous structure. The cheese-making begins in the normal way. The milk (usually from cows or

water buffalo The water buffalo (''Bubalus bubalis''), also called domestic water buffalo, Asian water buffalo and Asiatic water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also kept in Italy, the Balkans ...

) is warmed and curdled and allowed to rest for an hour before the

curd Curd is obtained by Denaturation (biochemistry), coagulating milk in a sequential process called curdling. It can be a final dairy product or the first stage in cheesemaking. The coagulation can be caused by adding rennet, a Kefir cheese, ...

s are cut into small pieces and the

whey Whey is the liquid remaining after milk has been curdled and strained. It is a byproduct of the manufacturing of cheese or casein and has several commercial uses. Sweet whey is a byproduct resulting from the manufacture of rennet types of hard c ...

is drained off. The curds are allowed to rest for a number of hours. Then follows the , which is when the curds are steeped for some hours in a bath of very hot whey, or water (for the temperature is 95 °C). Once they begin to float, most of the liquid is removed and the curd is mixed and kneaded until the required soft, elastic, stringy texture is obtained. The mass of curd is divided (often by pulling out a thick strand and chopping it) and shaped into individual cheeses. In the case of

mozzarella Mozzarella is a Types of cheese#Semi-soft cheese, semi-soft non-aged cheese prepared using the ('stretched-curd') method with origins from southern Italy. It is prepared with cow's milk or buffalo milk, taking the following names: * or mozz ...

, the process is now essentially complete—ideally these cheeses should be eaten within a few days. For other , such as provolone, , ,

burrata Burrata () is an Italian cow's milk (occasionally buffalo milk) cheese made from mozzarella and cream. The outer casing is solid cheese, while the inside contains and clotted cream, giving it an unusual, soft texture. It is a speciality of ...

, and , further processing is needed:

ageing Ageing (or aging in American English) is the process of becoming older until death. The term refers mainly to humans, many other animals, and fungi; whereas for example, bacteria, perennial plants and some simple animals are potentially biol ...

and, in some cases, brining or

smoking Smoking is a practice in which a substance is combusted, and the resulting smoke is typically inhaled to be tasted and absorbed into the bloodstream of a person. Most commonly, the substance used is the dried leaves of the tobacco plant, whi ...

Chemistry

Phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

groups attached to the

casein Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins (CSN1S1, αS1, aS2, CSN2, β, K-casein, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of ...

proteins in the cheese curd are highly charged but repel each other. Naturally high levels of

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

ions are found in the casein

micelle A micelle () or micella () ( or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated colloidal system). ...

s of the cheese curd and allow the casein micelles to form a more rigid network by bridging the

steric hindrance Steric effects arise from the spatial arrangement of atoms. When atoms come close together there is generally a rise in the energy of the molecule. Steric effects are nonbonding interactions that influence the shape ( conformation) and reactivi ...

created by the self-repelling phosphate groups. Calcium ions are removed during the production of cheeses. This increases the repulsion casein micelles have against each other, allowing the micelle to become less dense and more extensible. A relatively high amount of calcium is removed during the cheese making process, reducing the overall amount of this nutrient in mozzarella relative to other cheeses. Relative to cheddar cheese, mozzarella has 40% less calcium.

References

Italian cheeses Stretched-curd cheeses {{italy-cheese-stub

Chemistry

See also

References