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WORKING WITH EGG WHITES RECIPE BY TALLYRAND

This week I wanted to explain a little about the whys and wherefores of working with egg whites. A little bit of science in the kitchen folowed by an example recipe where you need to bear in mind what I am about to explain.

Whisking egg whitesWhy do egg whites foam?
If you try to whip plain water into a foam, you won't have much luck. Bubbles that form in plain water quickly pop. That's because water molecules stick together. Water molecules are electrically attracted to each other. They won't spread out to form a bubble film unless you add something that lessens the attraction.

An egg white is about 90% water and 10% protein. The egg-white proteins are long chains of amino acids that fold and curl into more or less spherical tangles. When you beat an egg white, these proteins uncurl and stretch out.

When the proteins uncurl, they expose amino acids that were hidden in the centre of the tangle. Some of the amino acids repel water; these are hydrophobic, or water-fearing amino acids. Some of the amino acids are electrically charged and are attracted to water; these are hydrophilic, or water-loving amino acids.

As you beat the egg whites, you also whip bubbles into the mixture. The water molecules and egg-white proteins bump around, jockeying for position. The water molecules are attracted to each other and to the hydrophilic amino acids on the proteins. While trying to get close to each other and to the hydrophilic amino acids, the water molecules squeeze the hydrophobic amino acids out. The best place for the egg proteins is on the surface of the liquid, with their hydrophobic amino acids sticking out into the air.

The surface of each bubble film becomes crowded with egg proteins. The water molecules are forced apart by these proteins. Since the attraction between water molecules decreases with distance, the water molecules don't stick together quite as well-they can spread out and make a bubble film.

Separating the water molecules so that they spread out in bubble films is only one step in making a meringue. The chicken egg contains a mixture of proteins that makes meringue possible. Some of the proteins form bonds with each other to create a stable network that keeps the bubbles from popping. When the meringue is in the oven, another protein-ovoalbumin-forms bonds that cause the meringue to stiffen.

Temperature does matter!
Egg whites at room temperature can be beaten to a foam more easily than cold egg whites.

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Why can't I use a plastic bowl?
Fat interferes with the formation of a good foam-and fat clings to plastic. No matter how carefully you clean a plastic bowl, odds are good that a bit of grease remains behind. It's preferable - and easier - to use a glass or stainless steel bowl to produce a fluffy meringue. Egg yolks also contain fat, so when you separate the eggs, try to make sure that none of the yolk ends up in your egg whites.

Why not add sugar at the beginning?
Adding sugar at the beginning can double the time you have to whip the egg whites to get a foam. That's because the sugar molecules get in the way of the egg proteins. With sugar molecules in the way, it takes longer for the proteins to find each other and form bonds.
When meringue is cooking, sugar helps keep it stable by bonding with water molecules and preventing them from escaping as water vapour. Delaying the evaporation of water from the foam helps keep the foam stable until it stiffens.

Why add vinegar?
Adding vinegar (or any other acid) can make the foam less likely to suffer the consequences of over beating: lumpiness, loss of water, and collapse. These undesirable consequences result from too many bonds forming between the egg proteins.

When you add an acid to a mixture, you are essentially adding some positively charged particles. These positively charged particles are hydrogen ions-hydrogen atoms that have lost an electron. The hydrogen ions hop onto charged portions of the proteins and leave them uncharged. Proteins that are electrically neutral are less likely to react with other proteins.

The Pavlova recipe is a good illustration of these points.

PAVLOVA RECIPE

Ingredients

castor sugar

400

gm

egg whites (room temp)

200

ml

white vinegar or lemon juice

1

tsp

corn flour

25

gm

vanilla essence

 

sq

Method

  • Place the egg whites and sugar in a stainless steel bowl over a bain-marie (double boiler)

  • Whisk the whites and sugar together until it reaches a temperature of 40ºC (it will feel just warm to the touch if you do not have a food thermometer)

  • Remove it from the bain-marie and continue beating it until it is completely cold

  • When the mixture is cold fold in the sifted corn flour and the vinegar

  • Add the vanilla essence to taste (approx. 2 tsp)

  • Place a large, deep bottomless cake ring onto a baking sheet lined with greaseproof paper or a silicon mat, spoon in the mixture and level it off with a palette knife

  • Run a knife around the inside of the cake ring to remove it and tidy the edges with a palette knife

or

  • Spoon mixture onto silicon mat (or baking sheet lined with greaseproof paper) and shape free form with a warm, wet palette knife

  • Cook in a warm oven 160°C just until the Pavlova starts to crack with little or no colour

  • Remove from the oven and allow to cool

  • Serve with whipped cream and fresh fruits or make it part of a larger dessert

Chef's Tip:

One large one or smaller individual ones may be formed and cooked.

The taller / thicker the Pavlova the better, as this ensures a creamier centre - about 15cm tall is ideal.

Success can also be had by making as per meringue (without the use of a bain marie) but the result is more of a meringue texture than a soft marshmallow inner).

Pavlova are best stored at room temperature, chilling them will cause the sugar to sweat out of them.

Enjoy and bon appetit . . . . .

Chef's terminology:

  lt
=
litres   tsp = teaspoon
  ml
=
millelitres   tbs = tablespoon
  kg
=
kilograms   sq = sufficient quantity (add to taste)
  gm
=
grams   pc = piece, meaning a whole one of

Tallyrand
Recipe from professional
Chef Tallyrand

Email Hub-UK : info@hub-uk.com