August 29, 2011

Eggs - what you need to know

Baking is a science of predetermined weights and ingredients. It is therefore important to ensure that the size and temperature of eggs are accurate to the recipe that you are using. Here are several tips to help you achieve that perfect bake. Knowing how the egg works will also help you understand why it is important to be exact in what you are doing.

WEIGHTS of eggs

Large  (old size 1-3 UK)
Medium       Small
In Shell
57g  2.01oz
50g1.75oz     1.5oz
Without Shell
50g  1.76oz = 1/4c = 4tbsp

White Only
30g  1.06oz      2tbsp+2tsp

Yolk Only
18g  0.63oz      1tbsp+1tsp

TIPS on Size
  • For half an egg - lightly beat one egg, then measure out 1 1/2 tablespoons.
  • Always use large eggs in recipes where egg size is not given
  • The size of the egg used will make a difference in the consistency of the batter and ultimately affects the outcome of the baked good
    If I half a recipe which calls for 1 egg, how do I halve the egg?
    One large egg = about 4tbsp - therefore 1/2 is 2tbsp. To get this put the egg in a bowl and lightly whisk with a fork until just incorporated. Separate out 2tbsp. 

    Freshness Test
    The air cell, or empty space between the white and shell at the large end of the egg, gets larger as the egg ages. When an egg is first laid it is warm. As it cools. the contents contract and the inner shell membrane separates from the outer shell membrane to form the air cell. (you see this when you peel a hard boiled egg)
    • Place an egg in water mixed with a little salt. If the egg is fresh it will sink. The quicker or farther it sinks, the fresher it is. If the egg floats, it has spoiled. or/
    • If you immerse an egg in cool water, you can judge how fresh it is by how high it floats. Really fresh eggs won't float at all (as the air cell is very small or not there at all). The higher the egg floats, the less likely it is to be fresh. or/
    • If you shake the egg and it sloshes around in the shell then it is likely to be old  - Fresh eggs make no sound (again because there is little air) 

    more EGG TIPS
    • Cold eggs are easier to separate than warm eggs. 
    • Separate eggs when cold and then warm egg whites to room temperature before using.  Make sure there is no egg yolk in the egg whites.
    • When separating the cold eggs, make sure no specks of egg yolk get into the whites or they will not whip to their full volume.
    • Most of us use eggs right from the refrigerator. As most recipes call for eggs at room temperature - remove eggs from fridge 20-30min before using them or if you forget, put them in a bowl of warm (not hot/boiling) water while you assemble the other ingredients. Dry them with a tea towel before cracking.
    • To maintain freshness it is better to store eggs in the fridge as they will last longer. 
    • Store whole eggs that are not in their shells for 2 - 3 days, covered tightly.
    • If the eggs are separated, you can refrigerate raw whites for up to 3 weeks  (cover with clingfilm) and unbroken raw yolks for 3 days (cover with clingfilm)
    • If you can’t use the yolks quickly enough, hard cook them just as you would cook whole eggs in the shell, drain them well and refrigerate them in a tightly sealed container for up to 4 or 5 days. 
    • For longer storage, freeze raw whites, sugared or salted yolks and cooked yolks for up to 1 year.
    • It's best to freeze the yolks separately from the whites because they store better and are handy when you only need part of the egg for your recipe
    • Store in a plastic bag and ensure you label what it is and how many egg (whites/yolks) are in the pack for easy reference. Take out of freezer and allow to thaw before using - doesn't take long but put in warm bowl of water if you are in a rush (ensuring no water gets inside)
    • If you want to store a whole egg, whisk it with a pinch of salt or a drop of corn syrup per egg to stabilise the egg proteins.
    • To achieve maximum volume when beating eggs, have them at room temperature  (triple in volume)
    • Start beating the egg whites at low speed, gradually increasing the speed to medium-high.  If you start at high speed the air bubbles created will be less stable as they are too large.  Adding cream of tartar (1/8 teaspoon for each white) and sugar will help stabilize the beaten egg whites.  Cream of tartar should be added once the whites are foamy.  Continue beating the whites and once they have reached the soft peak stage, gradually add the sugar (this ensures that the sugar fully dissolves into the foam).  The egg whites should be beaten until you have moist stiff shiny pointed peaks when the beaters are raised. 
    • Cream of tartar is added when beating egg whites to stabilize the whites and give them volume and strength. 
    Bowls to use
    • Have a clean copper or stainless steel bowl and beaters. 
    • Don't use a aluminum bowl as it gives the beaten egg whites a grayish tinge as some of the aluminum does come off during beating.  
    • Plastic and glass are not good surfaces either as the whites tend to slip down the sides of the bowl and plastic attracts grease because of its porous surface.
    • Perfectly beaten egg whites produce a baked good that has good volume and texture.  The foam needs to have a stable structure so it maintains its volume until the batter sets in the oven.  Always use the beaten egg whites right away as they start loosing volume immediately.  If you accidentally over-beat the egg whites, add one unbeaten white andwhipagain until stiff peaks form.  Remove 1/4 cup of egg white.
    Did you know......A typical step in some cake recipes is to cream butter & sugar and then add the eggs one at a time. This creates an emulsion.  Fat and liquid are by nature unmixable  - so the goal when mixing a recipe is to form a water-in-fat emulsion. A well emulsified cake batter should not be curdled or weeping liquid (this will happen if your eggs are cold and your mixture is at room temperature. If this happens the batter will loose air cells and your baked cake may be grainy or flat in texture, sometimes dry, flavourless, look uneven and may sink.

    How the number of eggs affects your bake 
    Check out site to see a brilliant description as to how and why the more or less eggs can affect your bake.

    Italian Meringue Buttercream 
    By adding hot sugar syrup to egg whites while beating them does not bring the egg whites to much above 135 degrees F and does not fully pasteurize them. If, however, you bring the sugar syrup all the way to the hardball stage (250 to 266° F), the whites will reach a high enough temperature.

    1 egg roughly sets 100ml of milk therefore if making 1l of ice-cream you will need 10 eggs
    Le Gavroche Pistachio Ice Cream recipe - my fav!

    About the Egg

    Chalazae: the cord looking thing hanging from the egg is the chalazae. The fresher the egg the stronger or pronounced the chalazae.  What's important is that it's essentially a rope of egg white that twists itself into being as the egg travels from the ovary to the nest. Its sole purpose is to keep the yolk centered in the egg. Remove it before using the egg. You may also have to strain a custard after baking to get rid of them or pieces .

    Structure of Egg Yolk
    • 1/2 water
    • 1/6 protein
    • 1/3 fat (5g)
    • emulsifiers (lecithin)
    • all of the egg's vitamins A, D, E are in the yolk. 
    • egg yolks are one of the few foods naturally containing vitamin D. The yolk also contains more phosphorus, manganese, iron, iodine, copper and calcium that then white. It also contains all of the zinc
    Structure of Egg Yolk
    • 7/8 water
    • 1/8 protein
    • 0 g fat
    • niacin, riboflavin, chlorine, magnesium, potassium, sodium and sulfur.
    Egg Nutrition Facts

    • high in cholesteral
    • high in saturated fats
    • good source of Riboflavin, Vitamin B12 and Phosphorus, and a very good source of Protein and Selenium.

    Free Range Eggs
    Free-range eggs are produced by hens that have daily access to an outdoor area with vegetation (weather permitting), although they are housed for the majority of the time in large barns. Even though the hens are housed indoors, they are never kept locked up in cages and the size of the flock is regulated. They are able to wander around and exercise even whilst they are kept indoors.

    Brown vs White Eggs
    Depending on the breed of hen, depends on colour of shell. There is no difference in nutrition  - one isn't healthier than the other.

    Grade A or Class A are the best 

    (UK) Another label to look out for is the Lion Quality stamp - eggs marked with this will have been laid by hens vaccinated against salmonella.

    Thank you to these online sources for all of the info found above:

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