Main ingredients | Eggs (typically chicken) | ||||||
---|---|---|---|---|---|---|---|
Variations | Baked eggs, starting temperature, preparation | ||||||
136 kcal (569 kJ) | |||||||
| |||||||
Boiled eggs are typically from a chicken, and are cooked with their shells unbroken, usually by immersion in boiling water. Hard-boiled or hard-cooked eggs are cooked so that the egg white and egg yolk both solidify, while soft-boiled eggs may leave the yolk, and sometimes the white, at least partially liquid and raw. Boiled eggs are a popular breakfast food around the world.
Besides a boiling water immersion, there are a few different methods to make boiled eggs. Eggs can also be cooked below the boiling temperature, i.e. coddling, or they can be steamed. The egg timer was named for commonly being used to time the boiling of eggs.
Eggs have a long history of use as a food source, following the history of the domestic Chicken, and recipes that include boiled eggs have been recorded since the first known cookbook, De re coquinaria , [1] in which at least one recipe calls for the use of preserved boiled eggs. [2] Alexander Pope is recorded as having recommended the method of cooking eggs over the embers or ashes of an open fire. [3]
The process of cooking an egg causes the proteins within the yolk and albumin to denature and solidify, resulting in a solid egg white and yolk. [4] Coagulation (denaturing) of egg white proteins begins in the 55–60 °C (131–140 °F) temperature range, and egg yolks thicken at the slightly higher temperature of 65 °C (149 °F), solidifying at 70 °C (158 °F). As such, the yolk of an egg will never solidify before the white, though in a boiled egg heat will take longer to reach the yolk through the albumin (compared to a fried egg), making this doubly true. [3] The process may be reversed through breaking the connections between the proteins, which has been demonstrated through the application of either sodium borohydride or vitamin C. [5]
There are variations both in degree of cooking and in the method of how eggs are boiled, and a variety of kitchen gadgets for eggs exist. These variations include:
Hard-boiled or hard-cooked [6] eggs are boiled long enough for the yolk to solidify (about 10 minutes). [7] They can be eaten warm or cold. Hard-boiled eggs are the basis for many dishes, such as egg salad, cobb salad and Scotch eggs, and may be further prepared as deviled eggs.
There are several techniques for hard-boiling an egg. [8] One method is to bring water to a boil and cook for ten minutes. [9] Another method is to bring the water to a boil, but then remove the pan from the heat and allow eggs to cook in the gradually cooling water. [7] Over-cooking eggs will typically result in a thin green iron(II) sulfide coating on the yolk, [10] though the coating has been reported as having little effect on flavor. [5] This reaction occurs more rapidly in older eggs as the whites are more alkaline. [11] Rinsing [3] or immersing the egg in cold water after boiling is a common method of halting the cooking process to prevent this effect, [4] and in commercial operations the discoloration is removed by immersing peeled eggs in a bath of organic acid after cooking. [12]
Hard-boiled eggs are recommended by the United States Department of Agricultural Food Safety and Inspection Service to be used within two hours if kept at room temperature, or within a week if kept refrigerated and in the shell. [13] [14] [15] Shelled hard-boiled eggs sold in bulk are pickled or sealed in an atmosphere of carbon dioxide and nitrogen for preservation. [1]
Hard-boiled eggs are commonly sliced, particularly for use in sandwiches. For this purpose specialized egg slicers exist, to ease slicing and yield even slices. For consistent slice sizes in food service, several eggs may have their yolk and white separated and poured into a cylindrical mold for stepwise hard-boiling, to produce what is known as a "long egg" or an "egg loaf". Commercial long eggs are produced in Denmark by its inventor Danæg and in Japan by KENKO Mayonnaise . The machine for producing long eggs was first introduced in 1974. [16] In addition to being sliced, long eggs can also be used in their entirety in gala pies. [17]
Haminados , braised eggs slowly cooked overnight, is a traditional Sephardic Jewish dish first documented in medieval Spain and now part of Israeli cuisine, where they are typically served on their own or as part of the Shabbat stew chamin and other dishes. [18] [19]
While the traditional egg timer counts to 3 minutes for cooking a soft-boiled egg, [20] some how-to guides recommend longer cooking times ranging from five [7] to six minutes. [21] Chef Heston Blumenthal, after "relentless trials", published a recipe for "the perfect boiled egg", suggesting cooking the egg in water that starts cold and covers the egg by no more than a millimeter, removing the pan from the heat as soon as the water starts to bubble. After six minutes, the egg will be ready. [22]
Soft-boiled eggs are not recommended by the Food and Drug Administration for people who may be susceptible to salmonella, such as very young children, the elderly, and those with weakened immune systems. [23] To avoid the issue of salmonella, eggs can be pasteurised in shell at 57 °C for an hour and 15 minutes. The eggs can then be soft-boiled as normal. [24]
Soft-boiled eggs are commonly served in egg cups, where the top of the egg is cut off with a knife, spoon, spring-loaded egg topper, or egg scissors, using an egg spoon to scoop the egg out. Other methods include breaking the eggshell by tapping gently around the top of the shell with a spoon. [25] Soft-boiled eggs can be eaten with toast cut into strips, which are then dipped into the runny yolk. In the United Kingdom and Australia, these strips of toast are known as "soldiers". [26]
In Southeast Asia, a variation of soft-boiled eggs known as half-boiled eggs are commonly eaten for breakfast. [27] [28] The major difference is that, instead of the egg being served in an egg cup, it is cracked into a bowl to which dark or light soy sauce or pepper are added. The egg is also cooked for 7 minutes, resulting in a runnier egg instead of the usual gelatin state and is commonly eaten with kaya toast and kopi. [29] [30]
Boiled eggs are also an ingredient in various Philippine dishes, such as embutido [31] and chicken galantina. [32] Boiled or steamed duck eggs that have been incubated for several days are also eaten in the Philippines, Vietnam, Laos, Cambodia, and Thailand as the food known as balut. [33]
In Japan, marinated soft-boiled eggs (味付け玉子, ajitsuke tamago) are commonly served alongside ramen. The eggs are typically steeped in a mixture of soy sauce, mirin, and water after being boiled and peeled. This provides the egg a brownish color that would otherwise be absent from boiling and peeling the eggs alone. Once the eggs have finished steeping, they are usually served on top of the soup. [34] [35] A similar method of cooking soft-boiled eggs popular in Japan is that of the hot spring boiled egg (温泉玉子, onsen tamago ), which is cooked at a constant temperature of 70 °C (158 °F) as is present in the volcanic hot springs of Japan, producing an egg with solid yolk and sol-like white. [1]
Boiled eggs often form part of larger, more elaborate dishes. For example, a boiled egg may garnish a bowl of ramen (often first marinated in soy sauce), be baked into a pie such as a torta pasqualina , [43] or be encased in aspic (similar to the French dish œufs en gelée, which features poached eggs [44] ). They may also be chopped and mixed with mayonnaise to form egg salad, or be deep-fried and then baked within a serving of lamprais. [45]
Boiled eggs can vary widely in how easy it is to peel away the shells. In general, the fresher an egg before boiling, the more difficult it is to separate the shell cleanly from the egg white. [21] As a fresh egg ages, it gradually loses both moisture and carbon dioxide through pores in the shell; as a consequence, the contents of the egg shrink, it loses protein, and the pH of the albumen becomes more basic. [3] Albumen with higher pH (more basic) is less likely to stick to the egg shell, while pockets of air develop in eggs that have lost significant amounts of moisture, also making eggs easier to peel. [46]
Keeping the cooked eggs soaked in water helps keep the membrane under the egg shell moisturized for easy peeling. Peeling the egg under cold running water is an effective method of removing the shell. Starting the cooking in hot water also makes the egg easier to peel. [21]
It is often claimed that steaming eggs in a pressure cooker makes them easier to peel. [47] Double blind testing has failed to show any advantage of pressure cooking over steaming, and has further shown that starting boiling in cold water is counterproductive. Shocking the eggs by rapidly cooling them helped, and cooling them in ice water for 15 minutes or longer gave more successful peeling. Shocking was also found to remove the dimple in the base of the egg caused by the air space. [21]
There are several foodborne illnesses associated with eggs, [48] most if not all of which are caused by pathogenic bacteria. [49] The harmful bacteria associated with eggs are mostly of the genus Salmonella , [50] but other harmful bacteria that can grow at refrigerated temperatures have been found in retail egg products, such as Bacillus cereus and Staphylococcus aureus . [49] Previous studies indicated that "the complete coagulation of [the] whole egg" was sufficient to destroy Salmonella bacteria, [51] but it is now known that the only factor in the inactivation or destruction of pathogenic bacteria in eggs is temperature. [50] Boiling eggs at a temperature of at least 62 °C (144 °F) for 30 minutes has been shown to inactivate Salmonella bacteria, [50] though the Food and Drug Administration recommends cooking at the higher temperature of 74 °C (165 °F). [48]
Bulk hard-boiled eggs have been linked to disease outbreaks such as listeria [52] and S. aureus infections, mainly from contamination and when eggs are not washed in the supply chain. [49]
Cooking, also known as cookery or professionally as the culinary arts, is the art, science and craft of using heat to make food more palatable, digestible, nutritious, or safe. Cooking techniques and ingredients vary widely, from grilling food over an open fire, to using electric stoves, to baking in various types of ovens, reflecting local conditions. Cooking is an aspect of all human societies and a cultural universal.
Poaching is a cooking technique that involves heating food submerged in a liquid, such as water, milk, stock or wine. Poaching is differentiated from the other "moist heat" cooking methods, such as simmering and boiling, in that it uses a relatively lower temperature. This temperature range makes it particularly suitable for delicate food, such as eggs, poultry, fish and fruit, which might easily fall apart or dry out using other cooking methods. Poaching is often considered a healthy cooking method because it does not use fat for cooking or flavoring the food.
A pressure cooker is a sealed vessel for cooking food with the use of high pressure steam and water or a water-based liquid, a process called pressure cooking. The high pressure limits boiling and creates higher temperatures not possible at lower pressures, allowing food to be cooked faster than at normal pressure.
In cooking, coddled eggs are eggs that have been cracked into a ramekin or another small container, placed in a water bath or bain-marie and gently or lightly cooked just below boiling temperature. They can be partially cooked, mostly cooked, or hardly cooked at all. Poached eggs are similar to coddled eggs but cooked by submersion in water, rather than being placed in a water bath.
Bouillabaisse is a traditional Provençal fish soup originating in the port city of Marseille. The word is originally a compound of the two Provençal verbs bolhir and abaissar.
Balut is a fertilized developing egg embryo that is boiled or steamed and eaten from the shell. It is commonly sold as street food most notably in the Philippines, Cambodia and Vietnam.
Deviled eggs, also known as stuffed eggs, curried eggs or dressed eggs, are hard-boiled eggs that have been peeled, cut in half, with the yolk scooped out and then refilled having been mixed with other ingredients such as mayonnaise, mustard and sprinkled with paprika, cinnamon or curry powder. They are generally served cold as a side dish, appetizer or a main course during gatherings or parties. The dish is popular in Europe, North America and Australia.
Sous vide, also known as low-temperature, long-time (LTLT) cooking, is a method of cooking invented by the French chef Georges Pralus in 1974, in which food is placed in a plastic pouch or a glass jar and cooked in a water bath for longer than usual cooking times at a precisely regulated temperature.
Separating eggs is a process, generally used in cooking, in which the egg yolk is removed from the egg white. This allows one part of the egg to be used without the other part, or each part to be treated in different ways. Recipes for custard call for egg yolks, for example.
Scalding is a form of thermal burn resulting from heated fluids such as boiling water or steam. Most scalds are considered first- or second-degree burns, but third-degree burns can result, especially with prolonged contact. The term is from the Latin word calidus, meaning hot.
Tea egg is a Chinese savory food commonly sold as a snack, in which a boiled egg is cracked slightly and then boiled again in tea, and sauce or spices. It is also known as marble egg because cracks in the egg shell create darkened lines with marble-like patterns. Commonly sold by street vendors or in night markets in most Chinese communities throughout the world, it is also served in Asian restaurants. Although it originated from China and is traditionally associated with Chinese cuisine, other similar recipes and variations have been developed throughout Asia. Tea eggs originated in Zhejiang province as a way to preserve food for a long time but are now found in all provinces.
A poached egg is an egg that has been cooked outside the shell by poaching. This method of preparation can yield more delicately cooked eggs than higher temperature methods such as boiling. Poached eggs can be found in several dishes.
A salted duck egg is an East Asian preserved food product made by soaking duck eggs in brine or packing each egg in damp, salted charcoal. In Asian supermarkets across the Western world, these eggs are sometimes sold covered in a thick layer of salted charcoal paste. The eggs may also be sold with the salted paste removed, wrapped in plastic, and vacuum-packed. From the salt curing process, the salted duck eggs have a briny aroma, a gelatin-like egg white, and a firm-textured, round yolk that is bright orange-red.
Low-temperature cooking is a cooking technique that uses temperatures in the range of about 60 to 90 °C for a prolonged time to cook food. Low-temperature cooking methods include sous vide cooking, slow cooking using a slow cooker, cooking in a normal oven which has a minimal setting of about 70 °C (158 °F), and using a combi steamer providing exact temperature control. The traditional cooking pit also cooks food at low temperature.
Lontong is an Indonesian dish made of compressed rice cake in the form of a cylinder wrapped inside a banana leaf, commonly found in Indonesia, Malaysia, and Singapore. Rice is rolled inside a banana leaf and boiled, then cut into small cakes as a staple food replacement for steamed rice. The texture is similar to that of ketupat, with the difference being that the ketupat container is made from woven janur fronds, while lontong uses banana leaf instead.
Haminados, also known as huevos haminados, chaminados, or braised eggs, is a traditional Sephardic Jewish dish popular in Israel. These eggs are cooked for a long time, resulting in red-brown whites and darkened yolks. The name is derived from the Hebrew word "ham," meaning "hot," reflecting the dish's preparation method.
Humans and their hominid relatives have consumed eggs for millions of years. The most widely consumed eggs are those of fowl, especially chickens. People in Southeast Asia began harvesting chicken eggs for food by 1500 BCE. Eggs of other birds, such as ducks and ostriches, are eaten regularly but much less commonly than those of chickens. People may also eat the eggs of reptiles, amphibians, and fish. Fish eggs consumed as food are known as roe or caviar.
Pasteurized eggs are eggs that have been pasteurized in order to reduce the risk of foodborne illness in dishes that are not cooked or are only lightly cooked. They may be sold as liquid egg products or pasteurized in the shell.
Century eggs, also known as alkalized or preserved egg, are a Chinese egg-based culinary dish made by preserving duck, chicken, or quail eggs in a mixture of clay, ash, salt, quicklime, and rice hulls for several weeks to several months, depending on the processing method.
Onsen tamago is a traditional Japanese low temperature boiled egg which is slow cooked in the hot waters of onsen in Japan.
When shell eggs are hard cooked, the protective coating is washed away, leaving bare the pores in the shell for bacteria to enter and contaminate it. Hard-cooked eggs should be refrigerated within 2 hours of cooking and used within a week.