Granular cheese, also known as stirred curd cheese and hard cheese, is a type of cheese

Cheese

Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

 produced by repeatedly stirring and draining a mixture of curd

Curd

Curds are a dairy product obtained by curdling milk with rennet or an edible acidic substance such as lemon juice or vinegar, and then draining off the liquid portion. The increased acidity causes the milk proteins to tangle into solid masses, or curds. The remaining liquid, which contains only...

 and whey

Whey

Whey or Milk Serum is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. Sweet whey is manufactured during the making of rennet types of hard cheese like cheddar or Swiss cheese...

. It can refer to a wide variety of cheeses, including the grana cheeses

Grana (cheese)

Grana originally referred to a class of hard, mature cheeses from Italy which have a granular texture and are often used for grating. These cheeses are typically made in the form of large drums. The structure is often described as crystalline, and the drums are divided by being split with a fairly...

 such as Parmigiano-Reggiano (at right) and various others. Many types are commonly used in the production of processed cheese

Processed cheese

Processed cheese, process cheese, cheese slice, prepared cheese, cheese singles or cheese food is a food product made from normal cheese and sometimes other unfermented dairy ingredients, plus emulsifiers, extra salt, food colorings, or whey...

, especially American cheese

American cheese

American cheese is a processed cheese. It is orange, yellow, or white in color and mild in flavor, with a medium-firm consistency, and melts easily. American cheese was originally only white, but is usually now modified to yellow. In the past it was made from a blend of cheeses, most often Colby...

, which by law must consist of Cheddar cheese

Cheddar cheese

Cheddar cheese is a relatively hard, yellow to off-white, and sometimes sharp-tasting cheese, produced in several countries around the world. It has its origins in the English village of Cheddar in Somerset....

, Colby cheese

Colby cheese

-History:Joseph F. Steinwand in 1874 developed a new type of cheese at his father's cheese factory near Colby, Wisconsin. The cheese was named after the village, which had been founded three years earlier....

, cheese curd, or granular cheese.

Food and Drug Administration standards

In the United States, the FDA mandates certain qualifications for something to be called granular cheese. The maximum allowed moisture content is 39 percent, and the minimum allowed milkfat content is 50 percent by weight of the solids. Regular granular cheese must either use pasteurized

Pasteurization

Pasteurization is a process of heating a food, usually liquid, to a specific temperature for a definite length of time, and then cooling it immediately. This process slows microbial growth in food...

 dairy products or be cured

Curing (food preservation)

Curing refers to various food preservation and flavoring processes, especially of meat or fish, by the addition of a combination of salt, nitrates, nitrite or sugar. Many curing processes also involve smoking, the process of flavoring, or cooking...

 for at least 60 days at a temperature of at least 35 °F. Either cows' milk or cream may be used as the main ingredient. Other permissible ingredients include clotting enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s such as rennet

Rennet

Rennet is a complex of enzymes produced in any mammalian stomach to digest the mother's milk, and is often used in the production of cheese. Rennet contains many enzymes, including a proteolytic enzyme that coagulates the milk, causing it to separate into solids and liquid...

, coloring, calcium chloride

Calcium chloride

Calcium chloride, CaCl2, is a salt of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation...

 as a coagulation

Coagulation

Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...

 aid, enzymes used in curing, hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...

, and agents used to protect against fungi. The name granular cheese can encompass many types of cheeses; for example, Parmigiano-Reggiano is a granular cheese.

Granular cheese for manufacturing must meet all of these standards except that it does not need to be cured, nor do the dairy ingredients used need to be pasteurized. This is the type of granular cheese most commonly used for processing.

Production

Although granular cheese can be created using any method that achieves the designated standard for physical and chemical properties, there is one method that is generally used. First, the milk or cream may be warmed and treated with hydrogen peroxide and catalase

Catalase

Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...

, producing water and oxygen gas. Then, a lactic acid

Lactic acid

Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

-producing bacterial culture is added, and the product is treated with clotting enzymes to form a semisolid mass. This mass is cut, stirred, and heated to separate the curd and the whey. Increasing the amount of time between cutting and heating will increase both the final moisture content and the milkfat content of the cheese, thereby increasing the yield. There follows an alternating cycle of draining of the whey and stirring. After most of the whey has been drained, the curd is salted

Salting (food)

Salting is the preservation of food with dry edible salt. It is related to pickling . It is one of the oldest methods of preserving food, and two historically significant salt-cured foods are dried and salted cod and salt-cured meat.Salting is used because most bacteria, fungi and other potentially...

, drained, and pressed into the desired form. The remaining product may be cured if the original dairy products were not pasteurized. A common method of curing is to dry the cheese on racks for about a week, then to wax it and place it in coolers until the time of consumption.

Taste

Granular cheese is rich and tangy. Although unpasteurized granular cheese is ready to eat after 60 days of curing, it has a very mild flavor unless aged further to increase sharpness. The cheese is sharpest after 12 months of aging, after which it is usually sold.