This article describes an engineering design task that engages students in the creation of polymers. The lesson follows the 5E format of Engage, Explore, Explain, Extend, and Evaluate. Students use the engineering design cycle to develop a polymer from milk and vinegar. Students are challenged to produce the most plastic using the fewest resources. During the explore phase students will vary the amount of vinegar; in the evaluate phase, they will vary the temperature of the milk. The article provides the lesson outline, student handout, and links to background information to be used by the instructor.