In art, fermentation can be understood metaphorically as a representation of transformation. However, as a biocultural phenomenon within a posthuman framework, it manifests a complex lattice of multispecies relationships, microbiopolitics, and metaphorical figurations that are adopted in works of art and biology as medium and content. In this article, the authors analyze artworks and projects that utilize fermentation by artists such as WhiteFeather Hunter, Amor Muñoz, Anna Dumitriu, and others. These works explore fermentation in the creation of biomaterials, its role in foods like cheese, and its status as a metaphorical figuration in hybrid mechanisms that give center stage to fermentation as a biocultural artifact embodying a nature-culture continuum in a microbial postanthropocentric framework.