Over 4,000 million eggs are consumed in Great Britain per year, and of these some 40% are home produced. This leaves about 2,400 million as being imported. The price of eggs is lowest in April, and highest in November, one being over three times the other. High as the number of eggs consumed per year for Great Britain may appear, yet it is less than two eggs per week each person, and it would appear likely that, were the prices more steady that a much greater consumption might be expected. As more eggs are actually produced here near April every year than at other months, and as this cannot be easily altered, it would seem that the prices of eggs might be more stabilised by more eggs being produced here, and any surplus stored. The price of eggs here has been proved to vary inversely as the home-produced supply quantity. The methods used in egg storage are three; the first one is that used for large commercial storage; the other two methods are used by those wishing to store smaller numbers or for home use, etc. There may be a few exceptions to these cases of course. The methods are :-(a) Storing in a suitable manner and at a low temperature, (b) Storing in a solution of water-glass, (c) Storing in lime water.

Before dealing with these three methods, something should be said about the eggs themselves. It is highly advisable for many reasons that only the best eggs are stored, and by " best " is meant to be included such points as freshness, size, uncracked shells, cleanness, and not contaminated in any way. All this means that each egg has to be examined. There is a so-called test for freshness that is sometimes mentioned, i.e., the " density test," in which test the eggs are put into a solution of 2 ozs. of salt per pint of water, and it has been stated that an egg 24 hours old will just sink in this solution. Also that one 3 days old will float easily. The test is unreliable ; as due to different thicknesses of the egg shell, totally misleading results can be shown. The eggs are therefore examined by the process of " candling," in which each egg is viewed by the light transmitted through it from one or other type of egg-lamp. These may be such that each egg is held by the operator by hand in front of the lamp, or it may be arranged that a large number can be done quickly, either by having the eggs in trays with a hole under each egg, this tray being placed over a box with a number of electric lamps in it, and each egg being turned over and round in its hole; or a perforated travelling belt may be used, the eggs being placed one over each hole, when the light is reached the egg is turned quickly as required, it then travels on and is taken off by assistants.

A fresh new laid egg white will appear clear and transparent with the air chamber at the large end about 3mm. in height, and the yolk dimly seen in the centre. An older egg has a larger air space, and the yolk has a more pronounced red tinge. Spots or patches in the egg are due to mould. A blood spot may be present, attached to the yolk, and such are rejected for storage purposes. There are two degrees of shell cracks, as well as cracks in the inner membrane termed an " air crack." Leakers are those in which the egg contents are actually leaking away, i.e., the shell and membrane are both broken, also shell cracks, i.e., those in which the shell is cracked, but not the inner membrane; both are to be rejected for storage. It is not generally realised that the egg shell is porous, many things can pass through it, even small solids, therefore it is clear that at least perfect shells are required on eggs for storage. Although some eggs look clean, yet none are really perfectly clean, and given the necessary time and conditions, the micro-organisms that may be on the outside may penetrate the shell and start affecting the contents. Next as to the size of the stored eggs, there is no good to be obtained by storing eggs undersized, for which top prices will not be obtained later on. Most of the imported eggs are graded as being of so many pounds weight per 10 dozen, i.e., 14, 15, 16 or 17 lbs., etc. It is not the general custom of the owner of the eggs produced in this country to grade them, and therefore the eggs may differ very much in cases.

By the cold storage of eggs is meant the storing at a temperature not below their freezing point, they are certainly not frozen eggs, " chilled " would be a better word.

It has been established that an embryonic change does take place in eggs at as low a temperature as 61° F., and therefore no eggs should be stored that have been up to that temperature for any real time. It is also established by tests that the average freezing point for egg white is 31°19 F., and for the yolk 30°-83 F., and also that as chemical changes may take place in an egg that is actually frozen, and as also unless it has an air space of at least 4 % of its volume, it will most likely burst, due to the contents expanding when frozen, it therefore is common practice to keep the temperature of the cold store to between 32° and 33° F. Now as stated before egg shells are porous, and if allowed to do so, contents will evaporate. To prevent this the air in the store must be kept up to a certain value of humidity, the egg then being in a damp atmosphere will not evaporate its contents. At any relative humidity below 99-6 % at 0° C. the egg will evaporate its water contents, this being shown later in a larger air space, which lowers the price obtained for the egg. At the same time a relative humidity as high as the above figure will increase the risk of mould growth, therefore a relative humidity of 80% at 0° C. is usually worked to. This means that air to this humidity has to be circulated through the store, and means taken to check it frequently, by hygrometers, etc., at the same time the temperature has to be maintained as near constant as possible. It has been ascertained by many tests that an important point is that of keeping the humidity at as near a constant figure as possible, in order to keep down the evaporation. Eggs can be stored, they losing less than .4% of their weight per month. A difficulty met with in storage eggs is the "storage taste," an unpleasant flavour, found in the yolk only; it appears to be a fact that given plenty of ventilation, and having the packing and containers made of metal, or something that will not absorb moisture and odours, that this trouble disappears. Now the moving of eggs from a cold store into the outer air will generally provoke a " sweating " of the egg, making the shell moist ; this is simply due to bringing the cold egg into a warmer atmosphere, and one that holds more moisture than is in excess of the saturation point at the egg temperature. The remedy appears to be to raise the store temperature gradually to that of the outside, or take the eggs into another part of the store that can be dealt with in that way. The objection to the shells being damp or wet is that they are not likely in that condition to fetch a good price, and the damp does favour the formation of mould, etc. As to the construction and arrangement of the stores, the eggs themselves are preferably stored in trays of perforated metal, these trays fitting into crates that can be stood on each other, the eggs being placed in the trays air-space uppermost. Whether cold air circulation into the store, or the installation of brine pipes in the store be adopted, depending upon circumstances of space, first cost, capital available, etc., the same precautions will have to be taken, that eggs are not frozen, that the air is of the required humidity, that the air is not too warm, and that conditions do not vary appreciably, also that the necessary arrangements can be made to prevent the eggs sweating on removal.

For small quantities of eggs methods as given below, are available. The Board of Agriculture and Fisheries recommend the following specific solutions :-

Water Glass

A strong solution containing approximately equal part by weight of sodium silicate and water is sold commercially. It is very viscous and has a specific gravity of 1-7. A 5% solution of this is a convenient concentration to use. (1 part of water glass to 15 parts of water is also recommended). Place the eggs in position in the container, and pour the solution over them.

Lime Water

Four parts of finely slaked lime are mixed with twenty parts of cold water, and the whole well stirred for several days to ensure saturation. One part of salt is then added and the clear solution decanted and poured over the eggs, which should be placed in suitable wooden, cement, or galvanised iron containers.

The general opinion of authorities is that the water glass method has greater advantages than the lime water method. The taste of eggs stored in water glass is excellent, they fry and poach perfectly, but for boiling the shell should be pierced at the broad end to prevent it cracking. A comparative test being made with eggs stored in lime water showed that such eggs were not so good, though the flavour was excellent, in all cases the air space had quite disappeared, and the white was more fluid, also most of the shells cracked, although they were first pierced before boiling, apparently the lime water made the shell brittle. It seems that the water glass completely seals up the shell in seven days, hence it must be pierced when boiling, but that the lime water never seals up the shell, and so lets water through into the egg, so filling up the air space. Of course all the precautions previously mentioned, re-selection and inspection of eggs, etc., must be carried out, even if stored in water glass or lime water. Also as far as can be done carry out the requirements of cold storage, i.e., do not let the temperature rise above 61°F., this should be quite easy by merely keeping in a cool place or cellar, etc.