Egg whites: Salt provides stability

This is how egg whites turn out perfectly

The art of a successful foam is to pack as much air as possible in as little protein as possible. Good egg whites can contain up to 99% air. However, you have to pay attention to a few things so that the egg whites turn out perfectly.

• Separate egg whites and yolks very carefully. Under no circumstances should only traces of egg yolk remain in the egg white, otherwise the foam result will be disappointingly unstable and not snow-white. Because the egg yolk contains lipids, i.e. fats. Incidentally, detergent residues have a similar effect.
• The mixing bowl should be high and absolutely free of grease. Professionals don't even use plastic bowls for whipping egg whites, as they fear that the smallest grease residues will always stick to the surface. Metal bowls are an alternative, many even recommend copper.
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• the Eggs should be at room temperature. Egg whites that come straight out of the refrigerator only provide poor egg whites because they are quite tough.
• The aim is to work air bubbles under the egg white and solidify it at the same time. If you do this - without an electric mixer - with two forks placed on top of each other, you can feel and recognize the gain in blisters and firmness with every handshake.


Fold in the egg whites - this is how it works

Many dough masses, whether for a light sponge cake or meringue, should be airy ...

• Incidentally, the egg white is stiff when the mass takes on a silky sheen and the lobed structures that are formed do not dissolve again by themselves. Then do not work any longer, especially not with an electric mixer, otherwise the protein network will become rigid and cannot hold the air bubbles.

Salt provides stability - an explanation at the molecular level

• One beats water With a whisk, bubbles form, but these rise quickly and burst on the surface.
• Protein also consists for the most part of water, but also contains about 10% protein, the proteins.
• Like almost all biomolecules, these consist of one or more chains of amino acids.
• They are not simply in the form of stretched threads in the protein, but are shaped in many ways.
• If you now process the egg white mechanically, these molecules are exposed to forces that gradually disentangle their shape - they become more thread-like. Chemists call this "denature".
• However, weak binding forces still act between the protein chains. As a result, they attach themselves to each other and form a kind of meshwork - an elastic network, which gives the egg whites stability.
• The mixed in air bubbles get caught in this network and are surrounded by the proteins like a protective cover, in between are the water molecules of the albumen - the foam is created.
• The more you hit, the smaller the bubbles and the foam becomes more stable.
• A kind of secret recipe for stable egg whites is the addition of a pinch of salt or a dash of lemon juice.
• In fact, acids and salts seem to dissociate into positively and negatively charged ions in a watery environment, such as egg white is. In this way you ensure that the protein chains stretch and then coagulate. This facilitates the formation of the important protein network and then stabilizes it.
• Too much table salt, however, binds all the water that is necessary for the surface membranes around the air bubbles. This gives the foam a rather dry consistency (and also tastes salty, which is not always desirable).
• You should also be careful with sugar. It may only be added to the finished egg whites because it also removes the water from the proteins. This will make the egg white syrupy and you will have a hard time getting air bubbles into it.
• However, if you add both after whipping, both a pinch of salt and sugar will strengthen the foam.