Once arriving at the Farm, we got straight to work so that we could attend the festivities of the announcement of the next president of the Colleges. Congratulations Dr. Gregory Vincent!
Now on to the important stuff, foams! Foams are dispersions of gas in a liquid. Today’s class focused on meringues and whipped cream. Meringues were the first to be created, due to the fact that they were to be baked into quenelles, which takes about 40 minutes if the temperature of the oven is set correctly (and longer if it is not, as we found out).
The control experiment was created using the following ingredients
3 egg whites
¾ cups sugar
Dash of vanilla
The final mixture went from looking like this…
When forming the meringue into quenelles, half of the batter was used to make plain quenelles, and the other half had semi-sweet chocolate chips added to them.
Because we are people of science, the control did not satisfy our hunger for foam knowledge. Seven other experiments were conducted to discover more about the mysterious nature of foams.
Experiment 1: Adding sugar before beating the egg whites into a foam.
In this experiment, the meringue generated had noticeably less volume and appeared much more glossy.
Here they appear near the control. The control is behind the dividing line, and experiment 1 is in front of the line.
Experiment 2: Using over beaten egg whites
When mixed, this meringue had much more volume than the control.
Experiment 3: Using brown sugar instead of white
The obvious difference between the brown sugar and the control was the color, however the brown sugar meringue was also heavier. The retained moisture of the brown sugar had a definite impact on the weight of the merengue.
Experiment 4: Whipping the meringue by hand
This meringue did not quite come to fruition. The egg whites were beaten into a nice foam, but when the sugar was added whipping became much more difficult. While we had strong, capable whiskers make their best attempts, the result was a soupy meringue that was unable to be formed into a quenelle.
Experiment 5: Adding lemon juice
Appearance was not much different, but had delightful lemon flavor.
While the meringues baked and our mixing bowl and whisk were cooling in the refrigerator, the class took a few moments to talk about our upcoming presentations at the Edible Science Fair. Topics were solidified and ideas were shared and generated in order to best prepare to give an informative, engaging presentation.
Once prompted by the timer to remove the quenelles from the oven, the class returned to the kitchen. While the quenelles looked delicious, we waited for them to cool before indulging on them. During that time we did not remain idle however! The groups that were unable to place quenelles on trays were getting their meringues into the oven. We also removed the whisk, bowl and cream from the refrigerator. It is ESSENTIAL that the materials for a whipped cream be cold, so that the solid fat globules of the cream do not melt and become liquid. This would destroy the foam! The fat globules are denatured by whisking and interact with the air and surrounding fat to create a sturdy, voluminous whipped cream.
Now that we had whipped cream, lemon curd, and cooled quenelles, the eating began!
When opening the control, it was easy to see that the meringue had cooked throughout. The inside of the crust was filled and full. It was interesting to see how heat could stabilize a meringue but destroy a whipped cream.
The control quenelles that contained chocolate chips were found to have air pockets inside of them. This is because the density of the chocolate chip crushed the meringue underneath of it. This was consistent of all the quenelles with chocolate chips.
The quenelles made from the meringue that had sugar added before mixing were found to have collapsed inside of their crusts. This was because the inside remained moist and dense and condensed during cooling. These had a crispy texture from the crust but were chewy on the inside.
The quenelles made using the over beaten egg whites were found to be very large and light, and contained large caverns within them. This could be due to the excess air pockets in the meringue. The fluffiness of the meringue did not support a sturdy quenelle.
The ones made with brown sugar looked similar enough to the other quenelles except for their distinctly darker color. Upon tasting, the difference was immediate. They also seemed a bit chewier; perhaps due to the extra water inherit of brown sugar.
The meringues that were whisked by hand did not make quenelles, but were delicious all the same. They baked into disks that had most if not all of their water boiled off. The ones with chocolate chips did not contain air pockets. This may be due to the wet, runny nature of the meringue used.
These quenelles were delicious and enjoyed along with our lemon curd and whipped cream.
Ref: McGee, H., Dorfman, P., & Greene, J. (2004). On Food and Cooking. New York, NY: Scribner.