Have you ever taken part in a food fight? There are foods flying left and right, and all you can think about is how you don’t want to get mustard on your new shirt. But instead of worrying about stains, you really should be thinking about density. This experiment presents a unique approach to biological agents by using the lens of density to look at the impact of yeast organisms in sugar fermentation. The hands-on activity allows students to investigate how the presence or lack of yeast can affect the overall density of a cinnamon roll. Students calculate density using a dimensional analysis that incorporates basic geometry skills, which makes the lab an excellent opportunity for a cross-curricular lesson with math. In addition to the biology and math content, the lab also looks at experimental design, asking students to identify the controlled variables within the experiment. Students are given one procedure, which they modify based on their assigned independent variable. This approach builds their understanding of the scientific method, knowledge of yeast reactions, and math application skills.