Milk, long a staple of the American diet, gets a cool, refreshing examination in this film that looks back at the introduction of swill milk as a means of disposing of brewery grain and forward to a future of alternative, natural dairy systems. Interviews with farmers, activists, and historians, together with a rich array of collaged and animated materials, reveal a contested, unexpected history. From presidential funding scandals to links with eugenics, milk consumption has been touted and normalized by political administrations, science, and agribusiness. On the other side of the pasture are those who argue that milk is an overproduced, industrialized food. Filmmakers Gerstein and McCollum's earlier Hybrid was a cultural history of genetically modified crops; here they observe cows engineered to provide more milk than can possibly be consumed, a lamentable waste.