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No. 26 (March 1959)
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THE EGG AND US

An egg is such a useful article it deserves respectful handling, but of all foods it is the one that suffers the most by cookery.

A fresh egg is heavy in proportion to its size and becomes lighter as it ages. A fresh egg sinks in cold water whilst a stale egg floats. This is partially due to evaporation of the water content of the egg through the porous shell, the air space becoming relatively larger, and also because in the staler egg, gases are formed within the shell due to decomposition of the contents. Eggs are often graded for freshness by a process known as candling. This consists of looking through the egg against a bright light when the size of the air space is clearly visible. When freshly laid there is a protective film over the egg which prevents this evaporation, so it is preferable that eggs should not be washed nor wiped.

STORAGE OF EGGS

Eggs stored for a short time should be kept in a cool dry place, and as they rapidly absorb odours, away from strong smelling foods. Broken eggs should be kept in a tightly covered container as should egg whites, eggs rapidly “dry up” if left uncovered. Egg yolks, provided that they are unbroken, are best covered with cold water. In all cases a cool place is essential for storage, a refrigerator is excellent, but shell eggs must be placed so that air can circulate around them freely. Eggs should be removed from a refrigerator some time before cooking and allowed to come to room temperature.

Eggs remain fresh for long periods providing the shell is made air tight. There are several ways of achieving this seal; the simplest are with a solution of waterglass (Sodium silicate) which deposits a film of lime on the outside of the egg shell, or by using a grease which is rubbed over the shell. Ordinary lard or vaseline can be used for this, but the special greases sold for this purpose are less likely to impart a taint to the eggs. Eggs greased should be stored in a perforated box without packing, and in both methods eggs should be placed for storage with the pointed end downwards. In this position the air space is in the correct place and the yolk is floating and will not stick to the side of the shell. Whatever method of preserving is used the eggs should be fresh, preferably not more than twenty-four hours old, infertile and unwashed.

The food value of eggs is not diminished by preserving, and preserved eggs can be used for egg dishes as well as baking.

BEATING EGGS

When an egg is beaten it forms a foam of many bubbles that have the ability to hold air. When these bubbles are incorporated into a mixture they lighten it—if the mixture is subsequently cooked the heat applied makes this air expand. Providing the heat is applied gradually the tiny walls of each bubble coagulate and the finished product does not collapse when it is cooled.

Whole eggs can be whipped to increase their volume about 6 times, egg whites will increase in 7–8 times and egg yolks about twice. Once eggs are whipped to their maximum volume they cannot expand further. Continued beating will then reduce the volume! Fresh eggs beat more easily than stale ones, but not too fresh 2–3 days old eggs give the best volume. Eggs also need to be cool to beat well, but not too cold; eggs from a refrigerator should be removed at least one hour before they are beaten for good results. Use the correct shaped bowl to suit the beater—if the bowl is too shallow the egg white will not cover the blades of the beater and beating will be a tedious process.

COOKING WITH EGGS

Eggs facilitate so many things in cookery that would otherwise be difficult or impracticable, such as making meringues or cream puffs or sponges or even a mayonnaise dressing.

Eggs set or coagulate at a temperature well below boiling point (212°F.), in fact eggs heated to 160°F. go tough and hard. This is important to know because eggs sometimes need to be added to a hot sauce or to hot milk for custard. When this is done the liquid must be below boiling point or the egg will set in hard bits and “curdle” the mixture. It is safer when adding egg to hot liquids to beat the egg first with a little of the hot liquid and then add this mixture to the remainder, than to add egg directly to the hot liquid. A sauce or custard must not be allowed to boil after eggs are added, but should be heated gradually until it thickens: if such a mixture shows signs of “curdling” (due to overheating) plunge the saucepan immediately into cold water, and beat the mixture well.

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When beaten egg whites are used to lighten a mixture, they should be folded into the other ingredients, and never beaten, as this causes the egg white to lose the air it previously held. Folding in is best accomplished with a metal spoon using a figure of eight movement.

Meringues, which are a combination of sugar and beaten egg white, sometimes go flat. This is due to the incorrect proportion of sugar and egg white (2 ozs sugar to each egg white) or by beating the sugar into the egg whites after they are fully beaten. When egg whites are beaten stiffly the sugar should be folded in, but sugar may be added a little at a time during the beating process—this latter method gives a closer textured meringue.

Baked or steamed custards that show holes in them mean that the eggs have been beaten too much, or that the custard has been cooked too fast. Custards or other egg dishes that are shrunk or weeping indicate again over fast or too lengthy cooking. Whenever eggs are one of the principal ingredients in a dish the cooking must be slow and gentle.

Cream puffs that flop, sponges that sink, or souflées that shrink down when taken from the oven all indicate too fast cooking, and that the egg isn't sufficiently coagulated, so that the shape is lost once the air contained in it contracts.

A variety of dishes are served under the name of scrambled egg, true scrambled egg should be very lightly beaten and cooked slowly. The mixture needs stirring to prevent it sticking and overcooking at the bottom, and is ready when the whole mass is almost set. It must not be fully set, or dry, or worst of all have reached the watery stage.

Eggs which have a tendency to crack when boiled may do so because they are taken straight from the refrigerator,—always run warm water over very cold eggs before plunging into boiling water. The greenish tinge that occurs round the yolk of hard boiled eggs is a sign that the eggs are over cooked, or have been cooked at too high a temperature or that they have not been cooled sufficiently quickly. For fast cooling crack the eggs immediately they are cooked and plunge into cold water.

Contributed by the Home Science Extension Branch, Adult Education Department, University of Otago.

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The boys of Rehua Maori Boys Hostel, Christchurch, have contributed their share in the raising of funds to enlarge the hostel. They formed a concert party and have raised hundreds of pounds through performances in Christchurch, Nelson, Timaru, Temuka and other places.