The fizzing and foaming in this experiment is produced by a chemical reaction between the vinegar (an acid) and the baking soda (a base). The products of this reaction are sodium acetate, water, and carbon dioxide gas. The carbon dioxide forms bubbles that are surrounded by the liquid. The laundry detergent decreases the surface tension of the liquid, effectively making the liquid more "elastic" so that the bubbles can grow large. The volume of gas produced and trapped in the liquid is much greater than the beaker can hold, so some of it spills over the top of the beaker.

The reaction of sodium bicarbonate to form carbon dioxide is the basis of its use as a leavening agent in baking. Cakes are solid foams. The foam is produced when bubbles of carbon dioxide from the reaction of sodium bicarbonate are trapped in the batter. As the cake bakes, the batter dries, and the trapped bubbles of carbon dioxide form the holes in the cake.