The invention is directed to an apparatus adapted to prepare a cultured food product, such as but not limited to tempeh, from a plant material. The apparatus comprises a housing, a container and at least one heating element. The container holds the plant material, such as a soyfood substrate, and is incubated in the housing whereby the cultured food product, such as a tempeh, is formed. The housing further comprises a controlled airflow wherein the housing is adapted to allow ambient air to flow into and out of the housing during the culturing process.