Conventional or Traditional Sponges

"Hmmm" we made sponges and we had some very interesting and varied results!Let's discuss briefly why the results in our products varied. There are two basic ways to produce a conventional sponge:

1) Warm Foaming.

2) Cold Foaming.

In the first method we warmed the eggs and sugar over a baire marie to 43 degrees celcius ensuring the sugar had completely dissolved.Why did we do this? This helps improve the emulsifying properties of the eggs, the warm eggs will aerate faster and create an emulsion which has greater stability. Remember if the eggs aerate faster we will also save time!

The cold foaming method only required us to pre-condition the eggs to 23 degrees celcius. We then aerated the eggs with the sugar. You should have noticed that this method takes a little longer for the eggs to reach the correct volume and consisitency. You will also have noticed that there is less stability in the egg foam because the mixture is cooler.

Why is it less stable when using the cold foaming method?

When we heat the eggs we change the nature of the protein in the eggs (De-nature), in other words we are encouraging the partial coagulation of the proteins and it is this which contributes to the greater stability in the egg foam.

Are you a little confused? Read the posting on proteins and coagulation, that should help, if you are still confused come and see me in class. Remember it takes a little time to learn something new!