What marvellous little things they are! They’re endlessly versatile, and full of nutrients. They can be used in cooking to make a variety of recipes, from custard to meringues, sauces and cakes.
I love them as they are, whether fried, poached, scrambled or boiled. I also keep a stash of hard boiled eggs, shell on, in the fridge so I can grab one as a non-fattening snack when hungry!
The versatility is due to their chemical and physical properties and the changes that occur when they are cooked. They are packed with protein, along with other nutrients such as vitamins A,D , E and B12.
Protein is made up of molecules called amino acids linked in a chain. When agitated , e.g. by whisking or heating, the links get rearranged.
Whisking egg whites creates bubbles and some of the amino acids form nests which stops the bubbles from popping.. Adding sugar, once the whites have formed gives the bubbles more stability, so you end up with a light fluffy meringue that holds its shape.
I remember whisking egg whites with children when teaching, to demonstrate ‘change of state’. Heat also changes the state of eggs. The amino acids cluster together and lock in water causing the yolks and whites to firm up – demonstrated in fried, boiled scrambled or poached eggs.
Mixed with other ingredients they make sauces, eg custard. When used in baking, the beaten eggs coats the air bubbles that form when creaming butter and sugar together, and then when in the oven the egg coagulates around the bubbles and stops them from bursting—hence light fluffy sponges.
Eggs also emulsify. An egg helps to combine two liquids, such as oil and water (which normally repel each other). Mayonnaise is made using oil and lemon juice or vinegar, and the molecules in egg yolk help them to combine into a creamy sauce.
Eggs can be a little tricky though. When overheated, they can turn rubbery, so for sauces they need slow cooking and constant stirring. Over whisking too can have disastrous results, causing water to be squeezed out of the egg whites and you end up with a grainy, watery mess.
There are pros and cons for storing eggs in the refrigerator or at room temperature. They keep longer in the fridge, but work better at room temperature for most cooking purposes. They can be brought up to room temperature if removed from the fridge half an hour before use.
Eggs can be frozen so long as the yolks and eggs are frozen separately, and in airtight containers. Add a good pinch of sugar or salt to egg yolks to stop them from being too thick when defrosted. Defrost them overnight in the fridge to thaw.
There is so much you can do with an egg (or a few)—so let’s get cracking.!