# Egg White / Yolk Separation



## yc (Aug 31, 2004)

I'm a newbie.  Does anyone know 
1) why we need to separate the egg white from the egg yolk when making cakes? 
2) why we need to whisk the egg white before pouring into the rest of the mixture?


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## Raine (Aug 31, 2004)

It is often necessary to separate egg whites and yolks for many recipes. Beaten egg whites are used in many baked items and desserts such as meringues, cakes, and soufflés, providing air and volume to the dish. Yolks are required for sauces such as hollandaise and mayonnaise and for sweet items such as butter cream frosting and custards. It is important to learn proper methods for separating eggs successfully.


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## Raine (Aug 31, 2004)

Egg whites are key players in many recipes and often are the reason for recipe failures. Egg whites should whip up high in volume yet be stable, moist and soft enough (even with stiff peaks) to fold easily into batter or spread for meringues. These tips will help make sure your whipping efforts succeed. 

Temperature
To ensure the greatest yield when whipped, whites should be at room temperature. Because warm eggs are harder to separate, however, separate them while they are still cold. Then bring the egg whites to room temperature by placing them in a bowl that is then set in another bowl of warm water. 

Hand Separation
The best way to separate eggs is with your hands. This is because you are less likely to break the yolk. Place two bowls on the counter. Crack the egg, and dump the yolk and egg white into one hand, over one of the bowls. Spread apart your fingers slightly to let the white fall through, into the bowl. Place the yolk into the other bowl. Make sure you thoroughly wash your hands before and after separating eggs. 

Shell Rescue
If you contaminate the whites with a small amount of yolk, use the shell to scoop out the yolk. 

Clean Equipment
Make sure the bowl and beaters are clean and free of fat. Even a small amount of fat, such as egg yolk or oil, can contaminate the whites and prevent them from whipping properly. As a precaution, lightly wipe the clean mixing bowl and beaters with vinegar or lemon juice. 

Best Bowl
A copper bowl is ideal to use for mixing whites. There is a chemical reaction between the copper and the whites, resulting in more stable whites. If you do not have copper, use a stainless steel bowl. 

Slow Start
Begin beating whites at medium-low to low speed until they are frothy. Then increase the speed to medium-high or high and beat continuously until they reach the desired stage. 

Whisk by Hand
If you consistently have problems with over-beating whites, try whipping them by hand using a copper bowl and a large balloon whisk with lots of fine tines. Doing so produces more stable whites and it is nearly impossible to over-beat them. 

Perfectly Whipped
Whites are perfectly whipped when they remain stable, even if you tip the bowl upside down. 

Folding Egg Whites
Sponge-style cakes are light and airy in texture. The cakes owe their texture to beaten egg whites and sugar that are folded with egg yolks and flour. The cakes' leavening, or rising power, comes entirely from the egg whites, so the step of folding the egg whites is critical. If you mix the batter too much when folding, the eggs will deflate and you will have a flat cake. 

After the egg whites and sugar have been beaten to stiff but not dry peaks, add the egg yolk mixture and half of the flour. To keep the mixture light and airy, add the flour using a sieve of sifter. 

To fold the mixture together, bring a rubber spatula straight down into the mixture and slide it across the bottom of the bowl, bringing it up the side and turning over the mixture. Move the bowl one-quarter turn and repeat the process until most of the flour has been incorporated. Not all of the flour will be completely mixed in - this is okay. 

Sift the remaining flour over the mixture, and repeat the folding process. This is a gentle process in which you are trying to keep as much air in the egg mixture as possible, so you want to be careful not to over mix. When you are finished, the batter should be light and airy; there may even be a few traces of flour or egg white that are not mixed in. If you over mix the batter, your cake may stay flat and not rise.


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## jasonr (Sep 1, 2004)

If seperating eggs is a problem, you can always purchase egg whites in little cartons at the grocery store. Although I don't mind seperating, sometimes I'll buy the whites in this way if either it would be extremely wasteful to seperate by hand (if you have a recipe that calls for ten egg whites, it seems like a hell of shame to throw ten perfectly good egg yolks in the trash) or if I am really working on an important recipe that I don't want to mess up, and I don't want to risk any possibility of contamination. Speaking of which, always be sure to use an intermediate bowl when seperating large numbers of eggs. Since inevitably, one egg yolk is going to be pierced when seperating many eggs, you want to prevent one accident from ruining an entire batch of whites. Seperate the white into a small bowl, and then add it to the larger bowl. This way, even if you screw up, the whites in the large bowl remain clean.


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## yc (Sep 3, 2004)

Thanks to everyone especially to Rainee's very detailed and useful explanation, including my another post on sugar.

I've successufuly made a Mascarpone Chocolate Charlotte today.  Thanks for everyone's support!


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## chefcyn (Sep 7, 2004)

*use for all those yolks...*



> ...(if you have a recipe that calls for ten egg whites, it seems like a hell of shame to throw ten perfectly good egg yolks in the trash) ...



Gold Layer Cake
--an Egg Yolk Cake

2 1/2 c cake flour
2 1/2 tsp baking powder
1/4 tsp salt
3/4 c butter
1 1/4 c sifted sugar
*8 yolks*
3/4 c milk
1 tsp vanilla
1 tsp lemon juice or fresh grated rind

Grease three 9" layer pans and dust with flour.

Sift the cake flour three times with the baking powder and the salt.  Set aside.
Cream the butter and gradually add the sugar, creaming until light.
In a separate bowl, cream the yolks until they are light and lemon colored.   Beat them into the butter mixture.  
Add the flour alternately with the milk in three parts, stirring just to blend after each addition.  
Add the vanilla and lemon juice/rind and beat two minutes. 
Bake at 375 for 20 min.  Sprinkle with powdered sugar.  Cool for a few minutes and remove from the pans. Let cool completely on a rack,  then frost with your favorite frosting.  An orange icing or seven minute frosting are both nice.


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