A downdraft gasifier is disclosed. The gasifier includes a biomass section that accepts and stirs raw biomass materials, a pyrolysis and tar cracking section having an inner cylinder for receiving biomass and an outer surrounding cylinder for gases from the biomass, and a char gasification section for receiving biomass and gases from the pyrolysis and tar cracking section. The char gasification section provides a grating and scraper for passing gases and ash and retaining biomass for char gasification on the grate.