Course: “Science and Cooking: From Haute Cuisine to Soft-Matter Science”
Format: One weekly 90-minute lecture by a visiting chef
One weekly 90-minute lecture by faculty instructors
Two hours of laboratory time each week (there are 10 lab sections for the 300-student class)
Prerequisites: None
Textbook: “Harold McGee, On Food and Cooking: The Science and Lore of the Kitchen” (revised edition, Scribner, 2004)
Grading: Weekly homework problems 20%
Section and lab participation 20%
Midterm examination 15%
Final project 25%
Final examination 20%
Homework problem: The diffusion coefficient of Ca2+ ions in water is about 1.5x10-9 m2/s. A drop of raspberry juice 1 cm in diameter is turned into a sphere by solidifying the outer layer. A) How thick is the shell of alginate formed after 20 minutes? B) How long will it take for the sphere to gel all the way through? C) How thick will the shell be if reverse spherification is used instead?
To solve that problem, students use this equation:
where Lshell is the thickness of the shell, DCa is the diffusion of calcium, and t is time, measured in seconds.
The problem assumes that the cook is using the standard procedure for spherification: First, add 50 grams of raspberry puree to a 150-gram solution of 99-percent water, 1-percent sodium alginate. Then drip the raspberry/alginate mixture into a calcium-chloride bath (typically 2-percent calcium chloride, 98-percent water).
Answers: (A) approx. 2.1 mm; (B) approx. 90 minutes; (C) again, approx. 2.1 mm, assuming that there are enough calcium ions in the raspberry/alginate mixture.
