The Chemistry of Food and Cooking-
Citric Meringue Pie
How does the ingredient you experimented with affect the food’s overall characteristics?
In this project, I experimented the difference in taste between an authentic lemon pie and a similar pie except the lemon juice was replaced with a proportional amount of citric acid. This did not affect the food’s characteristics very much because lemons are up to 8% citric acid and are commonly used as a substitute for lemon juice. However, when compared side by side with an authentic lemon pie the differences between the flavors become apparent. The citric acid pie is much sourer and “less mellow” than the authentic pie. A large reason behind this would be the difference in the introduction of the citric acid and the lemon juice. Lemon juice has a pH of 2 when fresh, but once put into a base it neutralizes and becomes about 7. Since lemon juice is acidic, neutralizing it involves mixing it into a formula with enough alkali ions to cancel out the acidic ions. Acids are defined to be substances that produce a high amount of hydrogen ions, or protons (H+). Bases, on the other hand, contain hydroxide ions (OH-), which when interacted with
Hydrogen ions produce H2O, like so:
H+ + OH– –> H2O
So, what does that have to do with citric acid and lemon juice? Because lemon juice isn’t pure citric acid, it neutralized faster and cleaner than the citric acid did in the filling. Based on this, I can derive that because the citric acid in the lemon juice was already diluted in the juice, there was less neutralizing that needed to be done than with the powdered acid. This is also supported by the fact that the previous pie that I made for the initial taste test was less tart than the one that I made for the exhibition. In the first trial, I mixed an extra ½ cup of water in the filling of the citric pie to account for the ½ cup of liquid that was supposed to be lemon juice. In the second trial, I forgot this step and tasted a stronger tart than the previous month, which was also supported by the feedback I received from the exhibition-goers. I believe that by not adding that extra amount of a base it resulted in a more intense tasting pie, meaning that there would have to be a sufficient amount of water in the pie to cancel out the complete tartness of the acid. Another reason behind this change in flavor comes from the presence of other acids in lemon juice, such as ascorbic and malic.
In what ways are cooking and doing science similar and in what ways are they different?
Cooking and participating in chemistry similar because they both require a level of specific measurements, a reactive and a product group, they both have an in-between “transformation” stage and require some outer source of energy to make happen. Take the Precise Amount of Copper lab, in that lab we were encouraged to derive how much iron we would have to substitute in a set amount of copper (II) sulfate to allow the iron to bond with the sulfate, leaving the copper in the mixture isolated. This required very specific measurements, went through a transformation stage where it went from one substance to another, and also needed our input of energy to take place. Think about it as if you were sifting dry ingredients for cake through a strainer, and you also accidentally spilled chocolate chips into it. The ratios of the flour, sugar and baking soda would need to be precise for the cake to bake properly, the transformation stage would be an unsifted mixture with unwanted ingredients to a sifted and chocolate chip free substance, along with the added input of our energy and eventually the oven’s to bake the cake.
In a sense, a chef is just a food chemist because the work has so many similarities, the difference being the materials worked with. Well, and a few other things. For example, cooking is a lot less precise than chemistry. While it is important to have accurate measurements so your cake will bake properly, a gram or two extra of flour isn’t going to ruin it. However, an extra gram or two in an actual chemistry experiment just might. For instance, if in the Precise Amount of Copper lab we had added even just slightly more iron than the copper, the reaction would still take place but the copper would no longer be isolated and would instead make a mixture with the excess iron at the bottom of the beaker we used. Another difference between chemistry and cooking would be that chemistry is typically viewed as microscopic, while cooking is macroscopic. In order to derive how much of a substance you need for cooking, you can eye-to-eye measure it out, while in chemistry you need to use mole conversions between formula units to grams in order to derive how much of a substance you need.
Here is my recipe card:
In this project, I experimented the difference in taste between an authentic lemon pie and a similar pie except the lemon juice was replaced with a proportional amount of citric acid. This did not affect the food’s characteristics very much because lemons are up to 8% citric acid and are commonly used as a substitute for lemon juice. However, when compared side by side with an authentic lemon pie the differences between the flavors become apparent. The citric acid pie is much sourer and “less mellow” than the authentic pie. A large reason behind this would be the difference in the introduction of the citric acid and the lemon juice. Lemon juice has a pH of 2 when fresh, but once put into a base it neutralizes and becomes about 7. Since lemon juice is acidic, neutralizing it involves mixing it into a formula with enough alkali ions to cancel out the acidic ions. Acids are defined to be substances that produce a high amount of hydrogen ions, or protons (H+). Bases, on the other hand, contain hydroxide ions (OH-), which when interacted with
Hydrogen ions produce H2O, like so:
H+ + OH– –> H2O
So, what does that have to do with citric acid and lemon juice? Because lemon juice isn’t pure citric acid, it neutralized faster and cleaner than the citric acid did in the filling. Based on this, I can derive that because the citric acid in the lemon juice was already diluted in the juice, there was less neutralizing that needed to be done than with the powdered acid. This is also supported by the fact that the previous pie that I made for the initial taste test was less tart than the one that I made for the exhibition. In the first trial, I mixed an extra ½ cup of water in the filling of the citric pie to account for the ½ cup of liquid that was supposed to be lemon juice. In the second trial, I forgot this step and tasted a stronger tart than the previous month, which was also supported by the feedback I received from the exhibition-goers. I believe that by not adding that extra amount of a base it resulted in a more intense tasting pie, meaning that there would have to be a sufficient amount of water in the pie to cancel out the complete tartness of the acid. Another reason behind this change in flavor comes from the presence of other acids in lemon juice, such as ascorbic and malic.
In what ways are cooking and doing science similar and in what ways are they different?
Cooking and participating in chemistry similar because they both require a level of specific measurements, a reactive and a product group, they both have an in-between “transformation” stage and require some outer source of energy to make happen. Take the Precise Amount of Copper lab, in that lab we were encouraged to derive how much iron we would have to substitute in a set amount of copper (II) sulfate to allow the iron to bond with the sulfate, leaving the copper in the mixture isolated. This required very specific measurements, went through a transformation stage where it went from one substance to another, and also needed our input of energy to take place. Think about it as if you were sifting dry ingredients for cake through a strainer, and you also accidentally spilled chocolate chips into it. The ratios of the flour, sugar and baking soda would need to be precise for the cake to bake properly, the transformation stage would be an unsifted mixture with unwanted ingredients to a sifted and chocolate chip free substance, along with the added input of our energy and eventually the oven’s to bake the cake.
In a sense, a chef is just a food chemist because the work has so many similarities, the difference being the materials worked with. Well, and a few other things. For example, cooking is a lot less precise than chemistry. While it is important to have accurate measurements so your cake will bake properly, a gram or two extra of flour isn’t going to ruin it. However, an extra gram or two in an actual chemistry experiment just might. For instance, if in the Precise Amount of Copper lab we had added even just slightly more iron than the copper, the reaction would still take place but the copper would no longer be isolated and would instead make a mixture with the excess iron at the bottom of the beaker we used. Another difference between chemistry and cooking would be that chemistry is typically viewed as microscopic, while cooking is macroscopic. In order to derive how much of a substance you need for cooking, you can eye-to-eye measure it out, while in chemistry you need to use mole conversions between formula units to grams in order to derive how much of a substance you need.
Here is my recipe card: