Biodynamic wines come from wineries that treat their whole farm as a closed-loop ecosystem. They try to grow healthy vines supported by holistic preparations of tea and manure preventatively, instead of reactively spraying with chemicals. These preparations are all produced on-site, leading to a polyculture style of farming instead of conventional grape monoculture. The producers will also often guide their production around a lunar calendar that critics write off as pagan. You can't argue with the results, though!