Last week in our class, we had the pleasure of filling the air of the science center again with the aroma of our tasty treats. This lesson we were learning about emulsions and foams using egg yolk and egg whites. Emulsion is the process of mixing two or more liquids in which one of the liquids is present as microscopic droplets distributed among another liquid. Emulsion is the process we used to create our mayonnaise. By adding vegetable VERY VERY slowly to 3 egg yolks and while beating vigorously (Sarah and I got a serious arm work-out) , we were able to create fluffy mayonnaise over the time span of almost 30 minutes. This process was rather interesting because Sarah and I originally added the vegetable oil in our egg yolks to quickly. Consequently, our mixture remained liquefied and the vegetable oil and egg yolk were separated. Only when we tried again (with more vigorous beating and adding the oil more slowly), were we able to suspend the oil droplets more effectively.
Bottom Left: Elle and Annie’s finished mayonnaise
Bottom Right: Amy and Sarah’s new mayonnaise about 10 minutes into beating
We also learned how to create a foam. This is when we trap pockets of air into a liquid or solid using mechanical energy. In our case, the procedure to make meringue involves beating egg whites with a electronic mixture until the mixture has pretty firm peaks. This took about 15 minutes of consistent beating. Sarah and I used granulated sugar while Elle, Annie, and Jocelyn used powdered sugar. The meringue with the granulated sugar definitely came out with firmer peaks and also tasted a little better (at least I thought so! But Professor Didem preferred the ones with powdered sugar). It was really fascinating to see how without actually performing any chemical reactions, we could observe physical changes to the mixture.
