Its majesty the egg
Eggs are one of the basic ingredients in almost all desserts.
The proteins eggs bring to mixed batters are a crucial element for the introduction of air, while the fat part contained in the yolk is
essential for the friability of pastries such as shortcrust pastry.
Yolk is used in creams to bind and emulsify thus adding to their creaminess.
Chicken eggs are the most commonly used in cooking and baking.
On the market we can find different types of fresh eggs, graded by weight:
- XL: over 73 g
- L: large, from 63 to 73 g
- M: medium, from 53 to 63 g
- S: small, less than 53 g
The most commonly used egg type in cooking and baking is the medium-sized egg, that usually weighs approx. 55g.
Excluding the shell the weights we need are:
- whole egg 50 g
- egg white 30 g
- yolk 20 g
I recommend you learn them because you will need them every time you have to convert the number of eggs into grams.
Once recipes used to call for a certain number of eggs, but over time it became clear that this could negatively affect recipe accuracy;
let’s say a baker added 10 eggs of 50g each, the total egg weight was 500g, but if he added 10 eggs of 70g each he would end up with
an excess of 200g, i.e. 4 eggs too much.
As we can easily imagine, the final outcome would be very different from the expected result.
Composition of Eggs
A whole egg is made of egg white and yolk; the average composition of an egg is:
- 73% water
- 13% proteins
- 12% fats
- 2% sugars and minerals.
Eggs are widely used for whipped batters such as sponge cake, choux pastry and standard shortcrust pastry.
The albumen (commonly called egg white) constitutes 60% of an egg, and consists primarily of:
- 88% water
- 10% proteins
- small amounts of sugars and minerals.
It is a clear colourless liquid that encloses the yolk.
In baking and pastry-making it is used mainly to prepare meringues and some other preparations.
The yolk is the innermost part of an egg; it is made of:
- 50% water
- 35% fats
- 15% proteins
An interesting aspect here is the presence of lecithin, a fat already emulsified in water we get “gifted” from Nature.
Besides fresh eggs, on the market we can find several types of eggs:
– fresh eggs: stored at +2°C they can last over two months
– freeze-dried eggs: they can last several months because they are dehydrated
– pasteurized egg shells: divided into egg white, yolk and whole egg. They undergo pasteurization and are later marketed in sterile boxes. In terms of hygiene they are safer than fresh eggs
– frozen egg yolk: the yolk is pasteurized, then homogeneized, granulated and finally frozen; it is used in ice-cream production and to
make creams and pastries
– sweetened yolk in a jar: usually preserved thanks to the very high quality sugar inside (minimum 50%); this product is widely used in
the production of ice-creams and semifreddi.
Raw eggs are runny and liquid; once heated they thicken and become solid.
Below you can find the cooking temperatures of eggs:
- 60°C egg white begins to coagulate
- 65°C complete coagulation of the egg white; the yolk begins to coagulate
- 70°C complete coagulation of the yolk
If other ingredients such as sugar, liquids, etc. are added the thickening temperature increases by several degrees Celsius.
A classic example is what happens with pastry cream, that reaches much higher temperatures than those indicated above due to the presence of sugar, starches and milk; if salt is added coagulation temperatures decrease.
The following information may substantially impact the outcome of your preparation:
– Fridge-cold eggs are ideal for shortcrust and brisée pastry
– Eggs heated up to 40-45°C are perfect for whipped batters like sponge cake because at this temperature eggs can incorporate more air.
- Excessive whipping speed causes the protein mesh of the eggs to break; consequently weak, nonuniform cavities will form in the dough
- Cold eggs hinders the whipping phase making processing times much longer
- Whipped batters containing large amounts of yolk form smaller cavities and make the dough heavier
- To increase the friability of shortcrust pastry replace part of the whole eggs with yolk
- To make leavened doughs softer replace part of the whole eggs with yolk
- To thicken and bind creams or batters made with ricotta cheese add a small amount of yolk
- Yolk can be replaced with whole eggs in cooked pastry cream.
Have a nice dessert!