Anosmia, or the absence of smell, is not just a subjective experience but, as I argue in this text, an ontological affect. Anosmia in the form of deodorisation and hygienisation, is the aim for many institutions, indeed often societies as a whole, that try to direct individual affects along prefabricated targets of racial, ethnic and class discrimination, rampant consumerism and unconscious participation in atmospheric engineering. Odours consist of what I would like to call the olflow, the incessant flow of odours (...) in which human and nonhuman bodies are agents of odour generation and consumption. Odour engineering directs the olflow and reinforces olfactory discrimination. I conclude with a call against the threat of what I call ‘ontological anosmia’, namely the flattening of multiplicity of desire and the engineering of emergence as spontaneity. (shrink)