Science and Cooking Labs

Pia Sörensen details how the Science of Cooking class conducts lab assignments through actual cooking experiences. For this example, she navigates through the Molten Chocolate Cake Lab/Heat Lab, but also attached three other examples for more resources. This experiment is supposed to help students understand the concepts of science and cooking in a practical setting by actually cooking or baking with the scientific tools and knowledge acquired through class.

Before starting the lab, students only need to attend lectures/watch online lecture materials, read lab procedure, and answer two question pre-lab about the lab procedure (see Lab Heat Transfer pdf to follow along with Sörensen's instructions). Before beginning the lab, the teaching fellow hands out the corresponding hand out, goes through some of the key concepts, then explains a few helpful pointers.

Tools Generally Required: Common cooking equipment and foods.

Example: Molten Chocolate Cake: Materials:

• 1 pot
• 1 induction burner
• 8 ramekins
• 1 medium bowl (wet ingredients)
• 1 small bowl (dry ingredients)
• 1 scale
• 2 cutting boards
• 1 ruler
• 1 spoon
• 1 knife
• 1 whisk
• 1 spatula
• 1 oven mitt
• 1 convection oven
• 120 g dark chocolate chips
• 113 g butter (1 stick)
• 120 g sugar
• 5 eggs
• 60 g flour
• 0.5 g (pinch) salt
•  Non-stick baking spray

Experiment Example, Molten chocolate lab: Procedure (estimated to take ~1 hr), last 15 min devoted to sketching the temperature distribution inside the baked cake, and using the crust thickness, L, to calculate the heat diffusion constant of cake batter.

1. Preheat the oven to 350°F (=177 °C) with the middle dial turned to “convection”.
2. Melt chocolate and butter on low heat while stirring.
3. Combine eggs and sugar in a medium sized bowl and beat until well mixed.
4. Combine flour and salt in another bowl and mix.
5. With one person whisking and another person pouring, slowly add the chocolate mixture to the egg mixture.
6. Little by little, add the flour and salt to the wet ingredients and whisk well. Make sure all of the flour is completely mixed with the batter.
7. One of the groups at your table will continue to the next step, the other group will gather for a demo of liquid nitrogen ice cream, and then come back to the next step when the oven is free.
8. Spray 8 ramekins with non-stick baking spray and place them on a cutting board.
9. Fill the ramekins with cake batter so that they are a little more than half full (~1.5-2 cm from the top edge).
10. Place the ramekins in the oven (middle rack).
11. Take out 1 cake after 10 minutes, 2 after 12 minutes, 2 after 13 minutes, 2 after 14 minutes, and 1 after 15 minutes and place them on a white tray.
12. Remove the cakes from the ramekins right after you take them out of the oven.
13. Slice the cakes in half and measure the distance of diffusion, i.e. the radius of the cake minus the radius of “uncooked” cake. Record your measurements on the worksheet. One of the student teams (with help from your TF) will prepare one ramekin with a heat probe sensor. The heat probe has four thermometers, each arranged to measure temperatures ~1cm apart in the cake. To set this up, follow these steps: 1. Attach the heat probe to one of the ramekins. Place the sensors in a line from the center of the cake to the edge of the cake (i.e. along the radius). 2. Place this ramekin in the oven (middle rack). 3. While baking, record the four temperatures as well as the oven temperature on the white board.

Ultimately, they produce a molten chocolate cake and use it to calculate the heat diffusion constant of cake batter (i.e. water), hand in a lab work sheet with their graphs, calculations, and sketches of temperature distribution in the baked cake. This will help students observe heat diffusion into a baked good, and use basic measurements to calculate a physical constant. Labs like this prepare students for final projects later on in the course.