lord of the meringues

Today’s recipe deals primarily with the different chemical properties of eggs. We made meringa con zabaglione, or meringue tarts with custard and berries in English.

The first step for us, and the first step in making pretty much any meringue, was to separate the egg whites from the yolks and create an egg foam. So we used the stand mixer to beat the whites until we formed soft peaks. At this point, we probably slightly overbeat the eggs, but oh well – once we added the sugar syrup, they came out totally fine, and we were able to achieve stiff and glossy peaks.

After whipping our egg whites, we shaped them into our tart shells and put them in the oven to bake.

While our tarts baked (and also stood in the oven to dry after), we began to work on the zabaglione custard. Zabaglione also features egg as the main ingredient, but the yolks are used instead of the whites – in fact, we used the yolks we separated from the whites earlier in the recipe.

To make the zabaglione, we heated a mixture of the yolks, sugar, and wine in a glass bowl over a saucepan of simmering water. For 30 minutes, we whisked this mixture until it thickened to the consistency of custard.

Finally, we assembled the tarts, topped them with berries, and voila!

• What chemical changes occurred when you made the meringue/meringa? What did you observe that told you these chemical changes were happening?
  • egg white foam creation – egg whites became thick and glossy after beating/addition of sugar syrup/citric acid
  • denaturation and coagulation – zabaglione became thicker while cooking

• What was responsible for the thickening of the zabaglione as you stirred it over the hot water bath?

Applying heat to egg protein causes it to coagulate, making it thicker and insoluble in water.

• Overheating (too fast and or too hot) the zabaglione can leave you with “scrambled eggs” – a lumpy grainy mess of clumps in watery liquid. What is happening in this case?

The application of too much heat to the egg mixture in too short a time period causes it to coagulate too quickly. Instead of becoming a smooth custard, slowly, at a low temperature, and over a longer period of time, it cooks to the consistency of scrambled eggs instead. This is why we used a steam bath in the process of cooking the zabaglione, in order to slow the reaction time and prevent the eggs from scrambling.

And here we are talking about the results of our merenge: