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Curdling is the breaking of an emulsion or colloid into large parts of different composition through the physio-chemical processes of flocculation, creaming, and coalescence. [1] Curdling is purposeful in the production of cheese curd and tofu; undesirable in the production of a sauce, cheese fondue or a custard. [1]
In curdling, the pH of the milk decreases and becomes more acidic. [1] Independently floating casein molecules attract one another, forming "curdles" that float in a translucent whey. [1] At warmer temperatures, the clumping reaction occurs more quickly than at colder temperature. [1] Curdling occurs naturally if cows' milk is left open in a warm environment to air for a few days.[ citation needed ]
Milk and soy milk are curdled intentionally to make cheese and tofu by the addition of enzymes (typically rennet), acids (including lemon juice), or various salts (magnesium chloride, calcium chloride, or gypsum); the resulting curds are then pressed. [2]
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In hot preparations emulsified with eggs like hollandaise and custard, curdling is the undesirable result of overheating the sauce. Sauces which contain starch curdle with more difficulty.
In cold sauces like mayonnaise as well as in hot sauces, too large a ratio of fat to egg may also cause curdling.
In sauces which include milk or yogurt, overheating often causes curdling. The higher the fat content, the less likely curdling is. Strained yogurt used in sauces also curdles only with difficulty.[ citation needed ]
When a plant based milk such as soya milk is added to coffee, curdling can sometimes occur. To help prevent this manufacturers sometimes add acidity regulators. [3]
When making cheesecake, if water is added to the cream cheese during the combining period, it will curdle.[ citation needed ]
Dairy products or milk products, also known as lacticinia, are food products made from milk. The most common dairy animals are cow, water buffalo, nanny goat, and ewe. Dairy products include common grocery store food around the world such as yogurt, cheese, milk and butter. A facility that produces dairy products is a dairy. Dairy products are consumed worldwide to varying degrees. Some people avoid some or all dairy products because of lactose intolerance, veganism, environmental concerns, other health reasons or beliefs.
Custard is a variety of culinary preparations based on sweetened milk, cheese, or cream cooked with egg or egg yolk to thicken it, and sometimes also flour, corn starch, or gelatin. Depending on the recipe, custard may vary in consistency from a thin pouring sauce to the thick pastry cream used to fill éclairs. The most common custards are used in custard desserts or dessert sauces and typically include sugar and vanilla; however, savory custards are also found, e.g., in quiche.
Yogurt is a food produced by bacterial fermentation of milk. Fermentation of sugars in the milk by these bacteria produces lactic acid, which acts on milk protein to give yogurt its texture and characteristic tart flavor. Cow's milk is most commonly used to make yogurt. Milk from water buffalo, goats, ewes, mares, camels, and yaks is also used to produce yogurt. The milk used may be homogenized or not. It may be pasteurized or raw. Each type of milk produces substantially different results.
Cottage cheese is a curdled milk product with a mild flavour and a creamy, heterogeneous, soupy texture, made from skimmed milk. An essential step in the manufacturing process distinguishing cottage cheese from other fresh cheeses is the addition of a "dressing" to the curd grains, usually cream, which is mainly responsible for the taste of the product. Cottage cheese is not aged.
Curd is obtained by 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 culture, or any edible acidic substance such as lemon juice or vinegar, and then allowing it to coagulate. The increased acidity causes the milk proteins (casein) to tangle into solid masses, or curds. Milk that has been left to sour will also naturally produce curds, and sour milk cheeses are produced this way.
Buttermilk is a fermented dairy drink. Traditionally, it was the liquid left behind after churning butter out of cultured cream. As most modern butter in Western countries is not made with cultured cream but uncultured sweet cream, most modern buttermilk in Western countries is cultured separately. It is common in warm climates where unrefrigerated milk sours quickly.
Soy milk, also known as soya milk or soymilk, is a plant-based drink produced by soaking and grinding soybeans, boiling the mixture, and filtering out remaining particulates. It is a stable emulsion of oil, water, and protein. Its original form is an intermediate product of the manufacture of tofu. Originating in China, it became a common beverage in Europe and North America in the latter half of the 20th century, especially as production techniques were developed to give it a taste and consistency more closely resembling that of dairy milk. Soy milk may be used as a substitute for dairy milk by individuals who are vegan or lactose intolerant.
Panna cotta is an Italian dessert of sweetened cream thickened with gelatin and molded. The cream may be aromatized with coffee, vanilla, or other flavorings.
Skyr is a traditional Icelandic cultured dairy product. It has the consistency of strained yogurt, but a milder flavor. Skyr can be classified as a fresh sour milk cheese, similar to curd cheese consumed like a yogurt in the Baltic states, the Low Countries and Germany. It has been a part of Icelandic cuisine for centuries.
Junket is a milk-based dessert with a jelly texture, made with sweetened milk and rennet, the digestive enzyme that curdles milk. It is usually set in a mould and served cold.
Ostkaka, ost meaning "cheese" and kaka meaning "cake" in Swedish, is known as Swedish cheesecake or Swedish curd cake, it is a Swedish dessert that has its roots in two different parts of Sweden, Hälsingland and Småland, though there are some differences between ostkaka from Hälsingland resembling halloumi in texture, and the soft-grained ostkaka from Småland. Originally, the food comes from Småland, ostkaka is made with raw milk and cheese rennet. However, these days most people simply use cottage cheese instead, which is much faster, and gives the same flavor and texture.
Okara, soy pulp, or tofu dregs is a pulp consisting of insoluble parts of the soybean that remain after pureed soybeans are filtered in the production of soy milk and tofu. It is generally white or yellowish in color. It is part of the traditional cuisines of Japan, Korea, and China. Since the 20th century, it has been used in the vegetarian cuisines of Western nations.
Requeijão is a milk-derived product, produced in Portugal and Brazil. It is a loose, ricotta-like cheese used to make cheese spreads. It can be a good substitute to mild, unsalty ricotta. This variety is sometimes sold in the markets wrapped in fresh corn husks. In El Salvador, cheeses such as requesón can sometimes be transported wrapped in banana leaves instead.
Tvorog is a European, non-liquid, white fermented milk product, traditional for Eastern, Northern and Central Europe, obtained by fermenting milk with subsequent whey removal. It is officially customary to classify traditionally prepared tvorog according to its fat content. According to GOST RF, tvorog is divided based on physical and chemical indicators into the following categories: fat-free, low-fat, classic and fatty. Also, according to the method of manufacture, such types of tvorog are distinguished as simple, soft, and grained tvorog, which is a type of low-fat tvorog.
A mechanical soft diet or edentulous diet, or soft food(s) diet, is a diet that involves only foods that are physically soft, with the goal of reducing or eliminating the need to chew the food. It is recommended for people who have difficulty chewing food, including people with some types of dysphagia, the loss of many or all teeth, pain from recently adjusted dental braces, or surgery involving the jaw, mouth, or gastrointestinal tract.
Strained yogurt, Greek or Greek-style yogurt, yogurt cheese, sack yogurt, kerned yogurt or labneh is yogurt that has been strained to remove most of its whey, resulting in a thicker consistency than normal unstrained yogurt, while still preserving the distinctive sour taste of yogurt. Like many types, strained yogurt is often made from milk enriched by boiling off some water content, or by adding extra butterfat and powdered milk. In Europe and North America, it is often made from low-fat or fat-free cow's milk. In Iceland a similar product named skyr is made.
Tofu is a food prepared by coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness: silken, soft, firm, extra firm. Tofu is also known as bean curd in English. Tofu originated in China and has been consumed in the country for over 2,000 years. Tofu is a traditional component of many East Asian and Southeast Asian cuisines. In modern Western cooking, it is often used as a meat substitute.
Laban rayeb is a type of curdled skim and fermented milk made in Lower Egypt. It may be drunk fresh or may be used to make areesh cheese, which in turn is used to make mish. There is evidence that it was made by the ancient Egyptians.
Quark or quarg is a type of fresh dairy product made from milk. The milk is soured, usually by adding lactic acid bacteria cultures, and strained once the desired curdling is achieved. It can be classified as fresh acid-set cheese. Traditional quark can be made without rennet, but in modern dairies small quantities of rennet are typically added. It is soft, white and unaged, and usually has no salt added.
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