Chapter: EGG COOKERY

EGG COOKERY

            Certain foods play a major role in cookery and the egg is one of them. It can be served as a main dish, as an accompaniment to other dishes or as an ingredient in a dish. Due to its versatility, the egg is considered a primary ingredient in culinary preparation, providing moisture, structure, and richness to a dish. It is also an emulsifier and an aerator when properly handled and used.                        

          In cooking, the term `EGG’ refers to the oval ovum of a bird (a cell from which a living organism takes birth and grows), used as food. There are many types of eggs, such as goose, duck and turkey. However, we are most concerned with the egg of the domesticated fowl called chicken. A recipe calling for egg normally means chicken egg unless otherwise specified.

STRUCTURE OF AN EGG 

         A whole egg is made up of yolk, white and shell. A membrane lines the shell and forms an air cell at the large end of the shell. The yolk is centered in the shell by the Chalazae .These are two white strands that are visible when the egg is broken.

SHELL: The shell or the outer covering of the egg may be white or brown. Shell color has no effect on the quality, cooking properties or nutritive value of the egg. The breed of the bird determines color of the shell. Composed primarily of Calcium Carbonate, the shell is extremely fragile. It is porous, which allows it to breathe. The porous nature of the shell allows loss of moisture even if the shell is unbroken. It consists of 12% of the total weight of an egg.

EGG WHITE: The egg white is the food and moisture source for the embryo in a fertilized egg. It accounts for 58% of the liquid weight of the egg. Egg white is made up of two parts. A thick white surrounds the yolk. Thinner, more liquid white is between the membrane and the thicker white. Albumin protein is the major component of the white. It also contains sulfur. The white is clear and soluble when raw. It is white and firm when coagulated. Albumin is the egg white valued by the cook and the baker for its ability to hold air when beaten. Beaten egg whites provide light fluffy texture for soufflés and light sponge cakes.

EGG YOLK: The yolk is the unfertilized embryo in the egg. Although normally yellow, the depth of color will vary with the feed of the hen. The yolk is high in fat and protein, and contains iron. The yolk is valued for the richness and texture it provides in both cooking and baking. It accounts for 30% of the liquid weight of the Egg. The colour of the yolk is dependent on the feed (diet)of the hen.Feeding yellower corn will yield yellow yolks as compared to feeding wheat and barley .Sometimes Marigold flowers are also added to the feed to increase the colour of the yolk.

VITELLINE MEMBRANE: it is a clear seal that holds the Egg yolk.

CHALAZAE: These are the twisted cord like strands of the Egg white. They anchor the yolk in the centre of the Egg. Prominent Chalazae indicate high quality.

SHELL MEMBRANE: This membrane surrounds the albumen. They form a protective barrier against bacteria. An Air cell /Sac is formed between these membranes.

AIR CELL/SAC: It is the pocket formed at the large end of the Sac. It is formed by the contractions of the contents on cooling after the egg is laid. The Air Cell increases with Age of the Egg. The Eggs are stored with the larger side facing upwards to keep the yolk in the center.

EGG SIZE CLASSIFICATION

Jumbo	70 gms	850 gms/doz
Extra Large	60-65 gms	765 gms/doz
Large	55 gms	680 gms/doz
Medium	48 gms	595 gms/doz
Small	40 gms	510 gms/doz

SOURCES OF EGGS                          GRADES OF EGGS

Ostrich                                                           AA

Goose                                                              A

Duck                                                                B

Turkey                                                             C

Hen

Pheasant

Guinea fowl

Quail

 (PLEASE REFER “FOOD PRODUCTION OPERATIONS” BY PARVINDER BALI FOR MORE DETAILS ON SOURCES OF EGGS AND GRADES OF EGGS)

SELECTION OF EGGS

        Eggs available in the market are graded according to their freshness, cleanliness, size, cracks and colour. With the exception of freshness these points can be told readily from the appearance of the eggs.

·      CANDLING

        To determine whether the egg is fresh or not, it is put through a process known as Candling by which the interior condition of the egg can be ascertained. this method of determining the freshness of an egg consists of placing a piece of cardboard containing a hole , a little smaller than the egg between the eye and the light, which maybe from a lamp or an electric light and holding the egg in front of the light. The rays of the light passing through the Egg shows the condition of the egg, the size of its air space, the growth of mould or the spoiling of the egg by any ordinary means.

·         The Bloom:

            When Eggs are freshly laid, the shell is covered with a substance called as “BLOOM” that gives it a feeling much like that of a thin lime coating deposited in a pan after the water boils.

           This coating disappears gradually as the egg is exposed to air, but as long as it remains, the egg may be considered as fresh and germ-proof.

·         Water Testing:

         A test for freshness which consists in placing the eggs in water has been found effective. A perfectly fresh will sink to the bottom, but if the eggs are 3 weeks old the broad end will rise slightly from the bottom of the glass. An egg that is three months old will sink into the water until only a slight portion of the shell remains exposed, if the egg is older or stale it will rise to the water until nearly half of it is exposed.

       Check for cracks in the shell which could let the bacteria in and contaminate the eggs. They should be less than 21 days old .the yolk should be plump and there should be two layers of white .if the egg is stale yolk becomes flat and the distinction between the two layers is lost. The final test will be the smell bad eggs will have an unpleasant odour.

STORAGE AND HANDLING:

            Protection of eggs is of great importance. When improperly handled, its properties as an ingredient and independent food item are greatly impaired.

- Eggs lose their qualities rapidly at room temperature. They should always be stored at 36-40°F (2C-5C).

- Eggs should be used within a month and stored unwashed, with the air sac on the top in the cold part of the refrigerator. Eggs have porous shells which allow air to enter the shells. They should be stored away from food, which are strong smelling and which may pass on their odors such as blue cheese, fish, onion.

-An hardboiled Egg will keep for 4 days if unshelled and 2 days if shelled.

-Once broken, an egg yolk will keep for 24hrs and an egg white for six to twelve hours in a refrigerator.

-One must also receive eggs in plastic crate rather than card board box as paper breeds germs and invites pests.

MARKET FORMS

     -Fresh eggs or shell eggs

-Frozen eggs (Whole eggs, Egg whites, Egg yolks)

-Dried eggs (whole, whites, yolks)

NUTRITIVE VALUE:

Nutritionally, eggs are important. They contain vitamins A, D, E and K. They also contain some of the B-complex vitamins. They are high in Iron and provide 15% of the protein requirement of the body. Eggs are low in saturated fats and one egg provides approx. 80 calories. The major concern with egg is cholesterol. One large egg averages 213 mg of cholesterol. This is fairly high for people who have restricted diets. Using the egg white only is part of the solution as most of the cholesterol is concentrated in the yolk.  The egg is unquestionably one of the best sources of food.

                                             

SULFUR: The familiar blue ring formation that you have often seen in a boiled egg is caused by cooking for extended periods at a high temperature. This is caused by the sulfur in the egg white, which combines with the iron in the egg yolk to form Ferrous Sulfide, a strong smelling compound that is deposited around the yolk. The best way to avoid this is to cook at low temperatures for the correct cooking time.

EGG FOAMS: Beaten Egg Whites are used to give lightness and rising power to soufflés, fluffy omelets, cakes and some pancakes. The following guidelines will help you handle beaten egg whites properly.

1.     Fat inhibits foaming: When separating eggs, take care not to allow any yolk to be mixed with the white. Yolks contain fat and this will inhibit the foaming. Always use very clean equipment to beat egg whites.

2.     Mild acids help foaming: A small amount of lemon juice or cream of tartar gives more volume and stability to beaten egg.

3.     Egg Whites foam better at Room Temperature: Remove the eggs from the cooler or refrigerator about an hour before beating.

4.     Do not over beat: Beaten egg whites should look moist and shiny. Over beaten eggs look dry and curdled. They have now lost their capacity as aerators.

5.     Sugars make foams more stable: Adding some sugar to partially beaten egg whites will make the foam more stable. It will retain shape for a much longer period of time.

Coagulation

The most important rule of egg cookery is a very simple one: avoid high temperature and long cooking times. In other words, do not overcook. Eggs are largely proteins, so the principle of coagulation is important to consider. Eggs coagulate at the following temperatures.

Egg Whites:  140-149°F or 60-65°C

Egg Yolks:  144-158°F or 62-70°C

Note that the egg white coagulates before the yolk. That is why it is possible to cook the egg with a firm white but a runny yolk. As the temperature of coagulation is reached, the eggs change from semi liquid to solid, and they become opaque. If the temperature continues to rise, they become firmer. An overcooked egg is tough and rubbery. Low temperatures produce the best-cooked eggs.

USES OF EGGS IN COOKERY

-It Thickens custard and sauces.

-Coagulated egg proteins help support cakes and breads. It binds together foods as in meat loaves and burgers. It also coats foods in form of egg based batters.

-To clarify consommé the egg white is beaten into the clear meat, when the white coagulates impurities are trapped and float in the form of a raft.

-It are used to make baked goods such as sponges, cakes.etc

-The egg yolk used as an emulsifier (lecithin –pigment) to make sauces such as mayonnaise and hollandaise.

-The yolk gives a crumbly quality to a rich cake.

COOKING EGGS FOR BREAKFAST

BOILED EGGS

-The term hard boiled is not a good one to use since eggs should be simmered instead of boiled.

-The eggs should be preferable at room temperature prevent the shell from cracking.

-Eggs may be simmered in water to soft, medium or hard boiled eggs.

Soft boiled: 3-4 mins

Medium: 5-7 mins

Hard: 12-15 mins

FRIED EGGS

-They should be always cooked to order and served immediately

-Always break eggs into a bowl so if there are any blood spots or broken yolks you can use it for another preparation.

-Use a well seasoned pan, heat it over low fire till warm, and then slide the eggs in.

-white should be shiny, uniformly set and tender not browned or blistered or crisp at the edges.

-yolk should be set properly according to desired doneness. Sunny side up yellow should be yellow and well rounded. In other styles the yolk is covered with a layer of coagulated white.

-it should be relatively compact and not spread out and thin.

Sunny side up (Cooked without flipping)

Over easy (flipped until the white is just set but the yolk still liquid)

Over medium (Flipped until the yolk is partially set)

Over well (flipped until the yolk is completely set)

SCRAMBLED EGGS

These are best cooked to order. Whites and yolks are mixed together along with sometimes milk/cream. They are normally served soft and moist unless asked for to be served “Scrambled Hard”.

POACHED EGGS

It is simple preparation, but there are several factors to attain a good looking poached egg.

-They should have a bright shiny appearance.

-Compact, round shape not spread or flattened.

-Firm but tender whites, warm, liquid yolks.

Factors influencing the making of a good poached egg:

-Make sure that eggs are very fresh (AA grade).

-Also the poaching liquid to be with salt, vinegar. The Acid in the liquid helps the protein to coagulate faster and hence retains the shape.

-the temperature should not be too hot as to create agitation, but hot enough to start cooking the white as soon as the eggs hit the water.

Remove the cooked eggs with a skimmer or a perforated spoon and drain them well.

Poached can be served plain, on toast or English muffins.

OMELETS

Cooking an omelet is difficult to master, needs a lot of patience and practice. A perfect omelet should be fluffy and moist, soft in the centre, yellow in colour with no brown at all

It should be oval in shape and continuous piece

Fillings can be added as per your choice.

SHIRRED EGGS

Shirred eggs resemble fried eggs, except that they are based in individual serving dishes rather than fried.

They may be baked with or garnished with a variety of meats and sauces.

Reference Books: “Professional Cooking “by Wayne Gisslen

                             “Food production operations” by Parvinder Bali